Tropical Fruit Forum - International Tropical Fruit Growers

Citrus => Cold Hardy Citrus => Topic started by: SoCal2warm on May 11, 2017, 11:53:01 PM

Title: Citrus in the Pacific Northwest
Post by: SoCal2warm on May 11, 2017, 11:53:01 PM
Temperatures & Climate of PNW Cities

The city of Olympia, WA happens to be farther north than Duluth, Minnesota. Heck, it happens to be farther north in latitude than Quebec City in Canada. (Don't believe me? Pull out a map)
And yet it is possible to grow some limited varieties of citrus here, and I'm not talking about those yucky borderline hybrids of Trifoliate Orange.

Firstly, temperatures. Olympia is in climate zone 8a. Winter nighttime lows tend to be 27F at the lowest. Looking back at temperature records, there were two separate 3-day stretches where the nighttime lows dipped down to 19F. These nighttime lows were all preceded by sunny days where there wasn't the cloud cover and marine influence that helps moderate the temperatures. So ironically, if you see an anomalous sunny day during the coldest part of winter, watch out! That's probably when the plants are going to need protection that night.

Ironically as you head just an hour or two north you move into climate zone 8b. This is because Tacoma and Seattle sit right against the sound and all that water helps moderate the winter low temperatures. In Olympia, by contrast, a lot of the marine air from the coast has to move over 50 miles of land, and by that time has had a chance to cool down a few degrees. That's not to say Olympia doesn't get any influence from the sound, but the city sits at the very end of the sound, where it's narrower, and ends up not getting as much influence from it. So Olympia may get just a week of light snow in the winter whereas Tacoma may get nothing. Probably the spot with the most moderate winter temperatures is Point Defiance, which juts out into the sound. Not surprisingly there's a plant nursery named Jungle Fever exotics located here.

The overall climate in Olympia and Seattle is not that different, but there are some differences. Olympia tends to have slightly hotter summers. Olympia also has slightly less sunny days per year, though the difference is very slight. Olympia gets a little more rainfall, since Seattle is subject to some extent to the rain shadow effect from the Olympic mountains. Seattle does have slightly higher winter lows than Olympia, both because of its location and because of the extensive urban development in the region. As we move further north into Vancouver, Canada, the winter nighttime lows are yet higher still than Seattle. This is because Vancouver sits right on the water and gets more direct access to the marine influence from the Pacific Ocean (through the Strait of Juan de Fuca). Temperatures are overall about 2 degrees cooler in Vancouver than Seattle, it's just that the lows points tend not to be as low. Victoria, on Vancouver Island, is practically subtropical. Well, as close as subtropical gets in Canada. There's someone with a farm out there growing Meyer lemons! While it is really on the borderline of the temperature citrus can survive in, the huge amount of marine influence probably means there are not devastating cold spells that come along every so many years. This is the case in Olympia, which may occasionally have a winter colder than other years. You can grow regular varieties of pomegranates, but every 8 years or so there will be a devastating freeze that will freeze kill them all to the ground. (Slightly more cold-hardy varieties can survive though)

When you go south to Portland, the trend continues. Portland is warmer, but it's also further inland. This can sometimes mean freak hail storms some years. Overall, Portland probably has just a tiny bit colder lows than Olympia during the winter, but also warmer highs. Certainly it's warmer during the height of summer, where sometimes it can get uncomfortably hot for 2 to 4 weeks. It's worth pointing out here that Portland appears to be the northernmost extent of where roses seem to grow very well (hotter, dryer summers and the longer growing season).

It's fair to say that the temperatures are not a huge degree different from Portland to Vancouver (Canada) but there are some small but significant differences. More like an overall trend as you head north over this regional stretch. It's not a coincidence these major cities are located where they are. Usually going higher in latitude would make things colder, but in this case the major cities have progressively more marine influence as one goes north along this stretch, which helps counteract the difference in latitude.

In case you're wondering why the Northwest experiences much milder winters than the Northeast, it's because winds bring warmer ocean air inland. When it rains, that also helps prevent the temperature from going too low, because water vapor releases latent energy of heat as it condenses. The West coast tends to get most of its precipitation during the winter.

So the Pacific Northwest has mild winters. But it also has a short growing season. The winter lows might not be too bad but those temperatures don't start getting up to where citrus needs for growing until around May. And as much rainfall as the Pacific Northwest gets, the trees are probably still going to need some watering during the dry summers.

Citrus Varieties that can be Grown

Yuzu can definitely grow outside in the PNW. Bloomsweet grapefruit can be reliably grown with just a little bit of minimal protection during the winter, starting in late December. (Make sure the plant is grown indoors during the winter under a grow light, some place warm, and where the indoor humidity won't drop too low, for the first two years to give the plant a chance to get some time to become established, because young small plants usually are not able to survive cold very well, not until they get to 2 or 3 feet high)
Satsuma mandarins have been grown in Olympia, though they don't tend to produce very well without some minimal amount of covering.
Ichang mandarins or Citrus taiwanica (Taiwanica lemon) should be no problem.

Some Overall Thoughts about the Historical World Movement of Citrus

It is ironic, from one standpoint. There are actually so many plants from Japan that are commonly planted in the PNW now. There's a fair amount of influence from Asia (particularly Northeast Asia) in the PNW region, which has come across from the other side of the Ocean. But cold-hardy citrus has not been one of this influences. Even in Southern California, virtually all of the citrus varieties came from Florida or, in a few number of instances, Texas.

The reason citrus has traditionally been viewed as a climate zone 10 fruit (or zone 9 at best) no doubt has to do with history and geography. While Asia was the heart of citrus growing, the traditional varieties that we are most familiar with were brought to Mediterranean Europe via the Muslims from India. Oranges were already growing in Spain before Marco Polo's journey to China, so since Europe already had oranges and lemons of their own, the citrus varieties in Asia were not seen as such a novelty. With the exception of pomelo which could never be grown in Europe. That would later get bred into grapefruit though, which could be grown in Florida and parts of Texas. America was settled from East to West, originally by peoples who came mostly from Western Europe, so this had a profound effect on the varieties of plants under cultivation. The particular varieties might not have been the most suitable to the lands being settled, but that's what they had, that's what they were familiar with. This in large part explains why the Mid-Atlantic Northeast was the first region to be primarily settled, because the climate was so similar to that of England and many of the same crops were suitable to grow there. It also explains why the Spanish were more successful at settling lands with warmer dryer climates more similar to their own (like in Mexico, Texas, and Southern California). Pomegranate and quince were traditionally viewed as warmer Mediterranean fruits. It was not until just two or three decades ago that new varieties of these fruits were brought to America from Southern Russia that were more cold tolerant and disease resistant in wetter climates. Although the Northwestern part of Europe has a cooler wetter climate, they were only familiar with the lineage of pomegranate and quince that had reached them from the Mediterranean, and this carried over into America as well. It's the same story with citrus, the citrus known in Europe were only those varieties that had originally been taken from China to India and cultivated in India (approximately climate zone 10).

Meanwhile, there were cold-hardier citrus being cultivated in remote parts of interior China, and in Japan cold-hardier citrus varieties were being bred (primarily from Yuzu that had been taken from China).

Oranges were probably quicker to culturally disseminate over long distances, gradually making their way to Europe, than mandarins were (despite mandarins being the more cold-hardy of the two) because oranges have a thicker rind and longer shelf life, so the fruit could survive a longer journey, to be tasted by someone else from another culture. Of course the citron was known in the Middle East since ancient times. Just had to add some historical perspective in this post.

On the subject of Bloomsweet and its origins from Japan, please see my post in this thread: "Bloomsweet" ( (it happens not to be posted in the Cold Hardy Citrus section which is why I'm giving you this link)

Thoughts on why the idea of trying to grow Citrus in the PNW never became popular

Well anyway, back on topic. While there has now been plenty of experimentation in Northern Florida, Texas, Georgia, and South Carolina growing citrus varieties outdoors, there is virtually no one in the Pacific Northwest growing citrus outdoors, despite the PNW being in the same official climate zone range.

And despite the PNW actually being much closer to the region of the world where all these cold-hardy citrus varieties came from (Japan and China). That's what I find so ironic.
Perhaps it's because all these areas (FL, TX, GA, SC) are so close to the citrus growing region in Florida. Whereas the PNW is so far away from Southern California, and in any case most of the citrus growing around the coast of California has since been destroyed due to the high land costs due to high population growth in that region. The commercial citrus growing in California has been pushed far inland, but then it can only go so far north before the winter lows get too cold.

So someone in South Carolina has commercial citrus groves growing a few hundred miles South of them, whereas someone in the far northern part of California has the San Francisco Bay area to the South of them. And then there are the coastal mountains in the northern part of the state, which means that the citrus growing would have to be very close to the coast, but then there is also all that coastal fog and clouds. It doesn't have those high temperatures and sunny weather citrus plants like. So I suppose the economics and geography on the West Coast are not as continuous as on the East Coast. On the East Coast it's merely a matter of temperature as you begin heading north from the Florida citrus belt. The region is much more flat, and surrounding land costs lower in the area we are talking about. What I mean is that, when you stop and think about it the reasons become pretty plain as to why there has been such little attempt at trying to start taking citrus northward on the West Coast; it's not such a natural progression or obvious inclination.

So maybe to summarize this post, there are reasons for everything, if we really want to examine them, but sometimes those reasons are kind of complicated.
I have so many thoughts here, hard to stay on one topic.
Title: Re: Citrus in the Pacific Northwest
Post by: rfelsch on May 12, 2017, 12:59:25 PM
What a wonderful post!  I recently moved to some Farm ground west of Portland (Banks, OR west of Hillsboro).  I am currently growing citrus and bananas in a hoop house.  I have Yuzu, Sudachi, Owari, Kishu, Gold nugget, Oro Blanco, and several others I am experimenting with.  I am hoping to see what can go outside, and what microclimate I can setup for them.  I am very eager to read more of your thoughts on the matter.  Again, thanks for the post.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on May 12, 2017, 04:08:01 PM
They recommend Poncirus rootstock to make sure the citrus goes into dormancy so it doesn't experience freeze damage.
In Portland, attempts at trying to grow these cold-hardy citrus outside with no protection generally have a 50% success rate. Whether a particular plant is going to be able to make it appears to be inexplicable. It's also worth pointing out that somewhere like South Carolina has a lot more heat during the Summer half of the year, so all that growth no doubt helps compensate for damage during a winter freeze. The PNW does not have that heat so much. If you really want your citrus to do well, that plant is going to need some transparent covering from Spring on to about May (give or take depending on how far north exactly you are). The plant may barely grow during this time but at least it will help prepare for Summer growth. The citrus should be able to keep growing until about September, when growth will slow to a standstill, though dormancy may not start until October, or even November.
(Covering in mid-October can be important just to keep the plant dry out of the rain to help it more seamlessly enter dormancy)

Fruit-bearing citrus in the PNW really needs some sort of covering for the first part of the year, and/or a good microclimate where it will get lots of sun and retain heat during the night. A large plastic bag covering and an LED bulb on an extension cord can work wonders, as well as putting some black-painted large containers of water inside the enclosure.

Again, young plants need protection. If it's under 2 feet it needs to go in a greenhouse or under grow lights during the Winter for the first few years (1 to 3 years).

Because of the high latitudes, and corresponding low angle of the sun in the sky during Winter, it's important to think about how sun exposure will change throughout the year in different spots. Before you plant, you might want to take a look outside during Winter at different times of the day to see which spots don't get much sun. This has more to do with trying to help prevent the plant from freezing at night. Put against a South-facing brick wall to help retain some of the sun's heat during the night. Or place a dark colored barrel of water behind it.

One guy even created a solar oven with a semicircle of reflectors focused on a black barrel of water with the plant in the ground right in front of it. Not sure how effective that was but it's an interesting idea. (Winter skies are completely overcast 85% of the time, but then again the coldest nightly lows usually hit right after the rare clear sunny days)

I recently moved to some Farm ground west of Portland (Banks, OR west of Hillsboro). I have Yuzu, Sudachi, Owari, Kishu, Gold nugget, Oro Blanco, and several others I am experimenting with.  I am hoping to see what can go outside, and what microclimate I can setup for them.
Unfortuantely where you are isn't going to be any warmer than Portland, because of those mountains blocking marine influence.

I do remember reading someone report about Sudachi being able to survive outdoors in Portland. It was protected from the wind.
Title: Re: Citrus in the Pacific Northwest
Post by: Citradia on May 12, 2017, 10:05:18 PM
I'm in the mountains of NC and I'm noticing that it doesn't get warm enough here for my citrus fruit to fully ripen before freezing temps happen in late October and growth just starting now in May. Despite stopping fertilizer in August, a final flush of growth happens in September. The growth that happens in September may survive through most of winter with raised tunnel and water Barrels, but invariably, all that growth gets killed by early spring; these are trifoliate hybrids and Ichang lemons I'm talking about. I started this cold hardy citrus adventure several years ago under the assumption that some of these trees were as touted, "cold hardy to 5 degrees F, or 10-15 degrees F with some protection ". Well, they're not. The only hybrid I have that didn't lose half of its height or more the past two winters is Dunstan citrumelo. The Dunstans left unprotected all winter did better than the other hybrids in high tunnel or the citradia with only water barrel protection. The tunnel was vented on both ends when not freezing at night to help keep trees dormant. The Dunstan in high tunnel looks good now in full leaf and all others look like crap; Ichang lemons, Thomasville ( it's actually just still dormant and leafless), citradia, nansho dai dai ( looks better than citradia or Ichang), rusk, mortan. My low this winter was 7 degrees and during the 80 degree February, my citrus started to break dormancy and put on little shoots of growth wether in or outside of tunnel. When we got two nights in mid teens in march/April, my trees were cut in half wether in tunnel or not, except for 5 out of seven Dunstans. Two Dunstans that Failed are planted out in open, not protected from wind, and are under black walnut tree which maybe weakens citrus afterall, even though I'd read that citrus isn't susceptible to juglone.  Bottom line, citrus, even trashy hybrids need heat and they don't like to freeze. If you live in south central FL or a coastal microclimate that looks like FL, you can grow citrus outside; otherwise, nontropical climate folks need to invest in plastic coverings and electric heaters for any outside citrus trees.
Title: Re: Citrus in the Pacific Northwest
Post by: rfelsch on May 13, 2017, 01:49:13 AM
Thanks for the additional information.   I built two 4'x20' planting beds insulated and heated with soil heating cables.  Both of these beds are inside my 20x30 hoophouse.  I am able to maintain 80 degree soil temperature throughout the winter with no problem.  The air temperature is another story.  I intend to grow most of my citrus in these conditions.  I intend to experiment outdoors with Yuzu, Saduchi and flying Dragon.  I fantasize about growing something more tasty outside such as an Owari or a another variety with better cold tolerance that I am unaware of.  This winter was exceptionally cold (got down to 7 degrees F. one night) (at least 3 weeks well below freezing) yet I was able to overwinter them with only a modest amount of supplemental heat.  I think I could use less heat by draping some agro-fabric over the trees on the nights below freezing and help them catch more of the heat radiating up from my soil.  Other than the several weeks of below freezing temperatures,  I did not heat the hoop house, just the soil.  I believe we have slightly milder winter extremes west of Portland because the occasional cold arctic blast that blows in from the east through the gorge dissipates up and down the valley without delivering the full force of that extreme this far west.  As you mentioned,  the radiational freeze on clear nights is the one to watch for. The other gotcha as you mentioned is the amount of light the trees receive.   Not sure how well I will be able to ripen fruit.  There is a guy south of here who was selling mandarins he grew in his hoop house.  I don't think he is using supplemental light.  He is heating it though.  When I measured the light inside the hoop house in the winter, it did seem to meet minimum requirements.   I think there is a significant amount of non directional light but the number of hours of light is low being North of the 45th parallel.   Not sure if the long days during the rest of the year will make up for the short days of winter.
Title: Re: Citrus in the Pacific Northwest
Post by: rfelsch on May 13, 2017, 09:48:44 AM
The link to the guy selling satsuma can be found here... (
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on May 15, 2017, 02:36:43 PM
I take back what I said about temperatures going up by May. It's May 15th and the daytime temperature outside is only 50 F (Olympia). It's been like this the last couple of days. It's because of the cloud cover. Ironically that same cloud cover that prevents winter temperatures from going below freezing also keeps temperatures low during the Spring. Earlier this month though there was a stretch of days where the temperatures were around 70 to 73 F.

50 F is not warm enough for citrus to grow in, the plants have gone back into a semi-dormant state, waiting for temperatures to rise.

Even all the other temperate deciduous plants that had begun starting to leaf out (beginning in late April) have stalled.

Fortunately the Summers tend to last later into the year because of the dryer weather and clear skies into the Fall season, and I also suspect the surrounding bodies of water play a role in absorbing and releasing heat, that may to some extent delay and prolong the onset of warmer temperatures over the course of the year.
Title: Re: Citrus in the Pacific Northwest
Post by: Citradia on May 15, 2017, 09:41:09 PM
I've been having lows in upper 40's/ low 50's with highs in 60's-70's this month, high of 84 today though. My citranges and Ichang lemons have stopped growing too; actually, barely started to show any new growth. Need higher temps.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on May 16, 2017, 08:32:03 PM
It might be 52 degrees outside, but it's almost uncomfortably warm being inside a sitting car. Just goes to show how much difference the greenhouse effect can make. It's also very humid now.

The sun came out briefly today, and the Satsuma is looking good. (But who knows, it hasn't gone through a winter yet, so maybe it might start declining the next 2 years. I'll cover it with transparent plastic sheeting to give it a head start this season)

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Title: Re: Citrus in the Pacific Northwest
Post by: Millet on May 16, 2017, 09:00:08 PM
Plastic seems like a good idea for frost protection, but it's just too thin to provide any insulation to plants. Since frost forms when leaf temperatures dip, simply covering the plant isn't going to be enough to protect it -- the trick is to use an insulated covering to capture heat that's radiating from the ground. Plastic that touches plants is even worse than no protection in many cases, since it can hold moisture against plant tissues and cause more serious freeze damage. However, when used as a row cover or placed directly on the ground around a plant, plastic can be an effective tool in the battle against frost. In general, you should toss plastic covers out of your emergency plant supply closet, but thick bedspreads, cardboard boxes and heavy curtains are still winners. Just ensure that when you cover your plant, the cover reaches the ground, trapping warm air under the plant's canopy. The better the cover does this, the safer your plant will be from frost. (
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on May 16, 2017, 10:22:15 PM
I really believe that with plastic sheeting, good sun exposure, and black colored water containers to retain heat, it's possible to prevent the inside air temperature from ever going below freezing. Since the very coldest it ever gets is -7 C (and very rarely that, usually more about -2 C on the colder nights), a 5 degree difference isn't all that much. And if the citrus plant never loses its leaves, that will greatly help compensate for the short growing season and prolonged state of semi-dormancy. You see, you have to identify the advantages the climate does have in the PNW and work off that. The PNW doesn't have the heat of climates in the South, so we have to instead tailor the strategy to use the relatively mild Winter temperatures. In the South, somewhere like GA, the plants can take some hard freeze, because the Winters aren't that long and once the cold season is over the plants will soon have those warm temperatures (and humidity) optimal for growing. That's not the case in the PNW. If the plant suffers severe damage, it's done for, it may not have the chance to recover.
Title: Re: Citrus in the Pacific Northwest
Post by: Millet on May 17, 2017, 10:43:25 AM
I notice you write "we" when you talk about growing in the pacific northwest, but your name and location is posted as southern California Z10.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on May 17, 2017, 12:48:08 PM
Two different growing locations.  :)
In this thread I'm talking about the PNW, zone 8a

It's very interesting, in SoCal I feel the urge to push the limits and try to grow things that are lush green from cooler more temperate climates. In the PNW I feel an urge to try to create a tropical or subtropical forest. I think it's the weather, over time I get tired of the weather and try to counteract it by growing things native to other climates with the weather I'm wishing for. This creates several challenges, of course. It seems like no matter where I am I'm trying to defy the climate. This explains why I have timber bamboo and cork oak growing in the PNW and cherry trees in SoCal. Maybe part of it is I just like variety, some things that are out of place in that climate and interesting. Of course citrus grows effortlessly in zone 10.
Title: Re: Citrus in the Pacific Northwest
Post by: Citradia on May 17, 2017, 09:34:01 PM
SoCal2warm, you are like me; we always want what we can't have.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on May 26, 2017, 12:01:48 AM
7 year old Yuzu tree in Vancouver BC, about 8 feet tall and bears over 200 lemons yearly

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source: (
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on June 06, 2017, 09:56:10 PM
A few plants from my little collection

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Yuzu in ground

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the middle one in the ground is an ordinary Satsuma, the one on the left is a Bloomsweet grapefruit, the one on the right (with the bag) is an Ichang lemon

these are in the PNW
Title: Re: Citrus in the Pacific Northwest
Post by: GregN on June 13, 2017, 12:03:02 PM
I have Meyer lemons, Bearrs lime, Juanita Tangerine, Changsha mandarins plus some trifoliate hybrids growing outside and in the ground. The best producer by a longshot is the Meyer lemons. however our growing season is short so for best results you must kick-start the bloom cycle in April otherwise the fruit will not be ready in time.  The Meyer lemons take about a year from flowering to using - so the tree must be kept above freezing through the winter - otherwise fruit loss will occur. I wrap the trees in incandescent Christmas lights, wrap in fleece then cover with a tarp. the light are turned on at freezing or below. My trees were planted 11 years ago and this process has seen them through the harshest of winters.

The non lemons have been problematic to get them to bloom - even though the Juanta Tangerine is 10' tall it has yet to bloom (???) I suspect it has to do with low heat and humidity. Ideas???

The greenhouse bushes seem to grow fairly well - as the trees thrive in the hot / humid environment.
Title: Re: Citrus in the Pacific Northwest
Post by: Millet on June 13, 2017, 03:14:25 PM
Greg N nice to see you again. Its been a while.  Regards
Title: Re: Citrus in the Pacific Northwest
Post by: crea2k on June 13, 2017, 05:24:23 PM
We have a similar climate here in the UK, I think it equates to zone 8b-9a mostly where I live. This guy here is growing citrus outdoors and on the few days we do get a frost just uses a tarp and a work light or heater to keep it warm. (
Title: Re: Citrus in the Pacific Northwest
Post by: Millet on June 13, 2017, 11:06:25 PM
crea2k  looking at the leaves of your friends tree, the tree is showing a deficiency of magnesium. and perhaps a slight deficiency of manganese. .
Title: Re: Citrus in the Pacific Northwest
Post by: crea2k on June 18, 2017, 04:08:33 PM
I dont know the guy, its just a youtube channel from a UK grower, it was just to show what sort of citrus can be grown outdoors in similar climate.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on June 26, 2017, 11:58:12 PM
Something I found while rummaging through the posts from another forum:

nancy sutton
Location: Federal Way, WA - Western Washington

"Well, just for giggles, I've got yuzu growing happily in a spot outdoors, sorta sheltered from the northerly wind, here in our 7-8 zone, gets down to 25F on short occasions.  No fruit yet... but it's only been ..? 2 or 3 years?"
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on September 07, 2017, 02:07:18 AM
Here's another post I found on gardenweb:

January 18, 2007
I'm in Washington State... have had a Changsha and Meyer Lemon outside for about 4 years. The Meyer gets hit pretty hard in the winter, but the Changsha seems to be a real winner. Been down to 14f this winter and it's still looking good (the Valencia seems to have bought the farm though).

Wow, I had to look up what "bought the farm" means. Apparently it = dead

I'm not 100% sure about Changsha in WA though, out in the open, completely unprotected. From someone else's account that I read it seems really borderline. (Their Chansha bit the dust in the record cold 2009 Winter, but they were in the Vancouver area, towards Portland, and that area does get slightly colder chill than the Seattle area)

Just wanted to post this here, maybe it can help give some of you hope.

Title: Re: Citrus in the Pacific Northwest
Post by: mrtexas on September 09, 2017, 07:24:19 PM
"got down to 7 degrees F. one night, at least 3 weeks well below freezing"

Edible citrus can't survive this. Trifoliate orange maybe.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on September 25, 2017, 06:44:51 PM
It's great weather for citrus right now. Right now it's 63 but that's pretty good considering it's overcast and raining. Yesterday it was 69-74, and in 3 days it's expected to go up to 85.
As I was saying earlier, the growing season starts late in the season, but it also extends late into the season (it's September 25).
Title: Re: Citrus in the Pacific Northwest
Post by: mrtexas on October 01, 2017, 11:39:15 AM
On average you can grow a mango tree outside in Seattle. However it is not the averages that kill a citrus or mango tree it is the extremes and the duration of freezing weather that kill semi-tropical trees. Mangos are killed by a freeze of any duration. 0F, 6F, and 11F kill citrus trees after an hour or two. Seattle has very little citrus friendly weather with cool, rainy and cloudy the most frequent occurences. Where I live in Houston has similar weather to Bradenton,FL where they grow mangoes outside unprotected. However the yearly hard freezes prevent growing mangoes in the ground unprotected.

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Title: Re: Citrus in the Pacific Northwest
Post by: Citradia on October 01, 2017, 09:19:13 PM
And, the reality is that if you live somewhere where it ever gets down to 5 degrees, you are going to have nights and days when it never gets above freezing, sometimes not getting above freezing for several days. If the temps don't rise above freezing when the sun comes up the morning after the cold snap, your citrus ( other than trifoliata) is in trouble.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on October 16, 2017, 04:38:10 PM

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Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on October 19, 2017, 11:28:35 PM
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Here's three of a really rare variety.
It's either ([trifoliate x Temple orange] x C. ichangensis) x Minneola Tangelo, or it's Minneola x C. ichangensis x Temple orange. There may have been a little mix up so its exact origin is in doubt.

I think this is only hardy to zone 8 but the fruit quality is supposed to be pretty good.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on November 03, 2017, 05:48:14 PM
At the very end of October the temperature early morning outside was 44°, 55° inside the greenhouse.
This morning, November 3, there was a surprise: the ground was covered in snow. It's very unusual for snow to fall this early in the year, usually any snowfall is preceded by two months of rain.

Here's a yuzu in the early fallen snow

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Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on January 28, 2018, 05:55:54 PM
Very unusual weather this year. Although there was snow in early November (very unusual), what's even more unusual is that so far, since then, there has not been a freeze, as far as I'm aware. Daytime temperatures have been hovering at about 46 °F almost every day, maybe 41 in the night (with just a few of the coldest nights down to 36 at the lowest).
 There was a rose on my bush blooming on New Years Day with several more buds that looked about to bloom, and I also just yesterday saw several blooms on a huge camellia bush. With temperatures like this a normal citrus tree could probably be left outside unprotected (although its leaves would have gotten a little frost bitten from the freak freeze in early November). It seems while the rest of the country has been experiencing deep freezes, the West coast has been unusually mild this year.
Title: Re: Citrus in the Pacific Northwest
Post by: Citradia on January 29, 2018, 09:43:39 AM
The weather on this continent is really unpredictable. We were supposed to have a warm dry winter, but it's been the exact opposite.
Title: Re: Citrus in the Pacific Northwest
Post by: Tom on February 01, 2018, 12:09:14 PM
The general explanation has been that the jet stream has been moving around in unusual patterns this year. Hard to believe but a dip in the artic jet stream caused central AL to be colder than parts of Canada at the same time. Yes it has been rough and the flu seems worse too. Tom
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on March 07, 2018, 12:32:43 AM
Check out this video: (

This guy has Miyagawa Satsuma fruiting on Flying Dragon trifoliate rootstock in Virginia Beach, right on the edge of the water. He's got a bunch of other rare cold hardy varieties grafted into the tree as well, Thomasville citrangequat, Ventura lemandarin, Glen citrangedin, Ichang lemon, Dimicelli, Shikuwasa, etc.
He's had the tree for a few years.
Virginia Beach is in climate zone 8a.

The video was taken December 10 and the leaves were all green. By February the leaves all turned brown and shriveled up (as seen in another video). The East Coast got pummeled by a pretty freezing winter this year. The only scion that didn't lose its leaves was a Swingle citrumelo. The tree suffered a lot of damage but he says it looks like it will come back.

few quick notes:
Ventura lemandarin is believed to be a cross between taiwanica lemon x either Satsuma or keraji mandarin; Glen citrangedin is apparently a cross between Willits citrange x calamondin; Dimicelli is a cross between Clementine x either trifoliate or CiTemple edible citrange

I just checked the weather report and the temperatures in Virginia Beach this week are looking pretty similar to here (March 6-13). Well actually the average in Virginia Beach is a little warmer but the colder days are still the same.

We did end up getting freezing temperatures and some snow in the second half of February, but it only lasted a few days. Again, this Winter has been very unusual.
Title: Re: Citrus in the Pacific Northwest
Post by: Millet on March 07, 2018, 01:16:52 PM
The Ventura lemandarin  that was seen in the above U-Tube was propagated by a friend of mine.  He is actually a member on this forum under the name of Eyeckr.  If you see him on, you can ask him any questions.  He know a lot about cold hardy citrus.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on March 20, 2018, 07:02:21 PM
The temperature inside that little outdoor clear plastic enclosure I showed you earlier was 90 degrees F.
March 20, 3:40 in the afternoon, full sun, thermometer reading taken on the ground laying up against the small tree. The temperature right outside, in full sun, set on the ground, read 71 degrees. I was surprised it got that warm considering the weather service says the temperature is only supposed to be 53 degrees right now. Maybe it's because it's in a protected space, against a South-facing wall in full sun. And the dark colored soil also probably absorbs light more strongly than other surfaces, helping things remain warm.

A temperature differential of 21 degrees between the inside and the outside. Obviously in full sun the greenhouse effect is playing a very big role here.
Even for something that's basically as thin as vinyl shower curtain.

Just took a temperature reading in the night, 11:20 pm, inside the enclosure it's 51 degrees, that's about 3 degrees warmer than outside. (March 21)

Another temperature reading, today it's cloudy cold and drizzling rain. 50 degrees inside the enclosure, 47 degrees right outside. (in the middle of the day around noon, March 22)
It appears when it's grey and overcast the greenhouse effect and temperature differential is not as strong. The weather service says it's supposed to be 42 degrees right now.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on March 31, 2018, 08:00:08 PM
found this post on forum:

dawn shears
Location: Gold Beach, Oregon (south coast, zone 9b)

"I was super tickled to find meyer lemon trees growing well, outside in my new community on the south Oregon coast.  Come to find out lots grows here that does not even grow well in many places in northern California...

They call it the "banana belt" of Oregon and it's something like climate zone 9b in a little sliver on the south coast..."
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on April 06, 2018, 05:10:22 PM
One of the interesting things I just learned, even though it doesn't get very freezing here in the Winter, and there are several subtropicals that are marginally able to survive here, the number of chill hours (between 32°F and 45°F) are around 3500 annually! (Yes, that's thousand) I had to look that up and double check it because I couldn't believe it. More than plenty enough chill hours for any temperate deciduous fruit tree you can think of. It's because of the extended season of cool temperatures and things not starting to warm up until later in the year. Right now, as of the beginning of April, we have New Zealand like weather. Yes, so imagine that. We have English Winters, a New Zealand Spring, Southern California Summers (maybe on the latitude of San Luis Obispo, sort of, it's fairly humid but with no precipitation, like the Southern California coast, but the hotter temperatures approach somewhere partially just a little further inland, but with cooler nighttime temperatures). Not really sure what you'd compare the Fall too. Maybe it starts off like the Northern part of California but farther inland where it's drier, and then suddenly transitions into buckets of rain pouring down, unlike any other region on earth.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on April 06, 2018, 05:14:49 PM
Just thought I would post this here from one of our other members in this forum:

jim VH
Vancouver,Wa. zone 8b
"Yes, My Sudachi and Yuzu easily survived 8F (-13.3C) in January 2017 in Vancouver Wa., just across the Columbia river from Portland Or., with only minor small twig damage and about 20% defoliation on each.  The Sudachi appeared to have a higher percentage of small twig damage than the Yuzu.  On the other hand, the Yuzu is a much larger tree, and size does matter."
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on April 06, 2018, 06:51:26 PM
Another interesting post from the forum:

Matt Hedlund
February 2018
"I too live in Seattle and have a cold hardy citrus collection of my own. In the ground i have:

Indio Mandarinquat
Owari Satsuma
Kuno Wase Satsuma
Nagami Kumquat
Fukushu Kumquat
Marumi Kumquat
Chinotto Sour Orange
Bloomsweet Grapefruit (kinkoji)
& Poncirus trifoliata

To date, these have all seen 18 degrees unprotected with no damage across the last 3 winters."

I think we should be taking this with a grain of salt though because being in an urban city can really insulate from the surrounding regional climate. Seattle near the water is in the higher part of zone 8b, perhaps almost bordering on 9a if you were only going by absolute low temperatures. All those paved surfaces and buildings dumping out heat into their surroundings make the localized climate just a little bit warmer during Winter. Anyway, I wouldn't be surprised if a severe Winter comes along in the next few years and freezes back half of everything he has.

Just in case anyone is thinking about trying this, the order of cold hardiness is:
calamondin < mandarinquat < kumquat

I don't really know whether calamondin or satsuma has more cold hardiness, I've read numerous conflicting reports. I'd have to guess they are probably near the same level.
If I had to make an educated guess, the varieties out of that list most likely to die would be Chinotto, with the Calamondin dying down to its roots before sending up new growth, while I can see the Satsuma and Bloomsweet struggling and not doing the best most years. (but this is just my intuition and I don't have any solid evidence to present to you right now to back it up)

This was posted by someone else in the same thread:

Frank Cordeiro
"My Yuzu limes have survived three days of 10 degree weather with just some minor stem damage.  It is producing lots of good fruit with no freeze damage the last two years.
I use my trifoliate orange to make a household cleaning solution by soaking cut up and squeezed oranges in white vinegar.
I am in Southern Oregon.  Most years we hit 10 degrees in winter but sometimes a bit lower... "
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on May 15, 2018, 08:39:18 PM
The Satsuma is beginning to put on new growth.
( (

Two weeks ago I had to open up the enclosure, it was getting up to 92 degrees (F) in there when the sun came out.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on June 07, 2018, 04:52:31 PM
Satsuma is blooming

( (
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on June 10, 2018, 03:11:15 PM
Here's a citrus labled "citrumelo" at Jungle Fever Exotics.

( (

It has a few blossoms on it.

They also have a small Yuzu in a container.
He doesn't have a greenhouse, he keeps all the plants outside.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on June 13, 2018, 09:37:16 AM
There's also an Ichang papeda growing in the Lan Su Chinese garden in Portland. It's in the ground planted up against a wall with good sun exposure. I saw a few small undeveloped fruits on it. The leaves smell slightly lemony but very mild, they don't smell like the leaves of Yuzu or Flying Dragon. It's definitely an Ichang papeda, I can tell by the leaves, perfectly symetrical sized leaf petioles and their plant guide also lists it as Citrus ichangensis.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on June 15, 2018, 08:27:13 PM
keraji seedling
( (
I planted it out in the ground mid-March and it lost all its leaves and partially died back just a little bit because of the cold temperatures, or sustained cool temperatures (not freezing though). However, it looks like it is now starting to come back, regrowing tiny little leaflets. I've been keeping it well watered.

Amazing, such a tiny seedling citrus would never have been able to survive out in the open ground in Southern California, the temperatures would be too hot and it would get dried out. So there is some irony to trying to grow in a cooler climate. It's very lush and green here and plants tend to grow very fast during the growing season (that is when the temperatures aren't too cool).
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on August 01, 2018, 06:00:42 PM
There was an interesting old thread on the Cloud Forest Gardener forum titled "hardy citrus, after the freeze", which discussed citrus growing outdoors in the PNW.

I'll copy some of the posts here in case the link disappears in the future.

Location: Vancouver Wa.
Climate Zone: sunset Z6, USDA 8b
Dec 02, 2010

Well, it's been over a week, enough time to evaluate the damage. While this freeze was not particularly severe compare to last year (48 consecutive hours below freezing with lows of 23F(-5C) and 17F(-8C) this year compare to 117 consecutive hours below freezing with four consecutive lows a degree around 11F(-11.6C) in December 09) the earliness of the freeze probably affected the plants a bit severely, since as Eric of the Dalles/gorge pointed out, plants have not had as much time to harden off compared to prior years.

I have a number of unprotected citrus that I'm evaluating for PNW hardiness, as well as some in christmas tree light heated mini-greenhouses. The greenhouse protected citrus were undamaged, fruit and all. In fact, it looks like the LA early Satsumas ripened a bit more, and may be ready by new years. The unprotected citrus:

Yuzu- the tips of the second growth flush were nipped back an inch or two, not surprising since the second growth flush never hardens off. This is comparable to previous years, except last year when all the second growth flush was killed.

Unprotected Changsha- slight tip dieback. This particular Changsha is the sole survivor of 23 unprotected seedlings I started out with two years ago, and survived (barely) last Decembers freeze, sort of unnatural selection of the hardiest variation of a random population.

Indio Mandarinquat- It's toast; white bark and dead leaves to the graft. Oh well, I was wondering where I was going to put the Kishu mandarin I'm protecting in a pot indoors.

Citrumelo- fully hardened off. No damage. It only had one growth flush this rather cool year.

Thomasville citrangequat seedlings- there are six in pots. The pots are set in the ground with soil to the top of the pot, to protect the roots. Three of them show some damage- slight bark whitening, tho the leaves look OK. The other three seem undamaged. There's also a one inch tall Sudachi seedling, which appears undamaged.

Las Palmas Norte
Location: Lantzville, Vancouver Island
Climate Zone: USDA zone 8b
Dec 02, 2010

My (potted) citrus had no issues with the last cold spell. They are in a large 1,000 square ft coldframe (polytunnel - British equivalant) and the smaller ones where just gathered together in the center area - no heat. I'm not sure of the temps in there but outside the coldest night on Nov.23 was -8.3°C (17°F).

Atwood Navel
Changsha mandarin
Owari satsuma
Ventura lemandrin
Meyer Lemon
10° Tangerine
... and several seed grown mandarins

My biggest problem was scale insect on some of these and now a black sooty mold has formed. Looks like a big maintenance issue come spring, should they make it.

Cheers, Barrie.


Location: Vancouver Wa.
Climate Zone: sunset Z6, USDA 8b
Dec 02, 2010

For an unprotected in-the-ground citrus, the Yuzu seems to work in the Portland area. My Yuzu has survived the last three winters unprotected. Part of it's hardiness, I suspect, is that it;s grafted to a true poncirus rootstock, giving it early dormancy. I haven't seen any problems with soot or scale. Perhaps because it's been outside, the rain washes off sticky sweet that causes sooty mold, and the freezes kill the scale. It's available from One Green World nursery, although I suspect, based on last years results, the 0F degree hardiness they claim may be overhyped. Also, it's actually used in cooking by the Japanese, although a lot of people don't care for the taste or texture. There are hardier citrus: the poncirus or trifoliate orange, the citrumelo, the citrange, etc. but most people can't stand the taste (although some are able to eat Citrumelo's, cutting out the sections like a grapefruit, which it resembles, making sure none of the bitter peel oil gets into the fruit. When or if mine sets fruit, I'll test the hypothesis). The following, somewhat more edible citrus may be as hardy, or hardier than the Yuzu, particularly if grafted onto a poncirus rootstock: Taiwanica lemon (seedy but edible, and, being a lemon, it will ripen here) Thomasville Citrangequat (some people don't like the taste, the one I got from Stan McKenzie tastes great, like a lime) Sudachi ( the one I have tastes fine to me, and it's used while still green, so ripening is not an issue. The ten degree tangerine, from Las Palma Nortes list, may also be hardy enough, and maybe the Juanita tangerine, but I haven't tried them (too many citrus, not enough room, or money) There are also things like yuzuquats and razzlequats and a host of other hybrids, enough to drive one mad

"George in Portland"
Climate Zone: 6/8b
Dec 02, 2010

i have a poncirus in the ground, and its been great. pretty close to my house, in the winter the contrast against the wall is incredible. stole that trick from the chinese gardens. it hasn't flowered yet though, making me sad...

John S
Climate Zone: USDA8
Dec 06, 2010

Don't buy a 10 degree tangerine. I think it makes it in SC because it gets so much heat that it can lose some. Mine died here. I waited to put it out until it was bigger, and it still croaked. I'm being a little conservative on my citrus. I will put my yuzu out eventually but I wan't it to grow up. Flying dragon and Ichang lemon the only ones out all year and they're fine.
John S


Location: Vancouver Wa.
Climate Zone: sunset Z6, USDA 8b
Dec 06, 2010

John, it's good to know about the 10 degree tangerine, something else to cross off the list. People who try out these different varieties help everyone else; out motto 'we kill exotic plants so others don't have to'. Even the Ichang can be iffy, mine was killed by last Decembers freeze, even though my grafted Yuzu survived. My guess is, the freeze came after a fairly warm November last year and sap was still flowing. When I inspected it, the bark was split and peeling, I'm guessing the flowing sap froze. The raging east winds probably did not help. If it had been grafted on Poncirus rootstock like the Yuzu, it may have gone dormant and survived.

John S
Climate Zone: USDA8
Nov 27, 2013

I love this thread. My yuzu died last winter, then regrew from roots and is a small bush again. Jim, I love your idea about growing it on flying dragon rootstock. Maybe I'll try to bud it this summer (2014). I have been almost killing my citrus for years. I love to see the experiments of others to see if I'm on the right track.
John S

Location: Vancouver Wa.
Climate Zone: sunset Z6, USDA 8b
Nov 22, 2014

This is an update of this thread about the travails and joys of growing cold hardy citrus in the PNW, detailing the outcomes of nine unprotected citrus during the winter of 2013-2014.

Last winter was characterized by two significant Arctic blasts.

The first began Dec. 5th 2013 and ended Dec10th and was characterized by 113 consecutive hours below freezing, one low of 10.8F (-11.8C), one low of 13.6F (-10.2C), and four lows in the low 20's. Daytime highs were in the mid-high 20's on four of those days. This freeze also had strong east winds of 20 mph with gust to near 40 during the first couple days.

The second blast began Feb. 4th and ended Feb. 9th 2014 also with 113 consecutive hours below freezing. The nighttime lows were not particularly remarkable (for Portland), with three around 19F (-7.2C). What WAS noteworthy was a period of 36 consecutive hours where the temperature never rose above 21F (-6.1C). Daytime highs were also low-mid twenties for two other days.

The compost pile indicator shows that the ground froze solid to a depth of 12-15 inches during each of these two extended freezes.

Four of the nine unprotected citrus survived these two freezes:

Yuzu on Flying Dragon rootstock: 30% defoliated, one small twig died

Citrumelo on Flying Dragon rootstock: 20% defoliated, no small twig death.

Thomasville Citrangequat on Flying Dragon rootstock: 100% defoliation, 30-40% small twig death

First of twoThomasville Citrangequat seedlings on its own roots: killed to the ground, regrew one shoot in late July

The following five unprotected citrus died:

Troyer Citrange on it's own roots: This was the rootstock of the Kishu mandarin that died the previous winter.

Small 5 YO Changsha tangerine on it's own roots: This was the seedling that barely survived four nights near 10F in the of freeze of Dec. 2009. Not this time. Two freezes in one winter were two much for it , I guess.

Large 9 YO Changsha tangerine on it's own roots

Second of two Thomasville Citrangequat seedlings on it's own roots

Sudachi on Carrizo Citrange rootstock

A few additional observations
All of the five citrus that died looked pretty good until the weather warmed in late March, whereupon they turned brown and died. In fact, I was able use the wood in February to graft the two Changsha's and the Citrangequat seedling onto Flying Dragon rootstock, indicating the wood was still alive.

Second, none of the Citrus showed any signs of the bark splitting that indicates sap was flowing at the time of either of the freezes. Clearly they were all dormant.

Apparently, then, on the five plants that died ,it was the roots that were killed when the ground froze to a depth of 12-15 inches, i.e., the citrus themselves were top-hardy to 10F, but not root-hardy. The one Citrangequat one it's own roots that survived perhaps had a deep root that somehow survived, the root possibly protected by some Lingonberry plants that were growing fairly close to it.

This, then, seems to be a second mechanism whereby Deciduous Poncirus rootstock improves the hardiness of those cultivars grafted onto them. Not only does the rootstock cause the tops to go dormant, protecting it from bark-splitting death, but it also gives it a set of freeze-proof roots.

I was a little surprised that the Citrange died. It is reputed to be hardy to zero Fahrenheit. But then, Portland is a "hard" zone 8. Freezes here can last for up to two weeks without the temperature exceeding freezing, whereas in the South and Southeast, where most observation come from, temperatures of near 0F are often followed by rapid warmup above freezing in the following day or two.

Base on observed damage, the Citrumelo is somewhat hardier than the Yuzu. Both can probably take a few more degrees of frost, possibly to 5F, or even lower.
Both are hardier than the monofoliate clone of Citrangequat that I obtained from Mckenzie farms. The two Citrangequat seedlings appear hardier than that clone- both had some bifoliate and trifoliate leaves.

Only one of the Citrus -the Changsha- was grafted. The Sudachi was a rooted cutting. (

Title: Re: Citrus in the Pacific Northwest
Post by: Millet on August 01, 2018, 10:13:17 PM
SoCal2Warm thanks for the post.  I'll have to spend some time looking it over.  Appreciate your kindness.
Title: Re: Citrus in the Pacific Northwest
Post by: jim VH on August 02, 2018, 11:41:44 AM

Thanks for copying that stuff over from the Cloudforest forum.  Since it went defunct I've been unable to post the results from the 14 day  arctic blast of January 2017 during which the temperature never rose above freezing, except for one day where it rose to 34F.   One low was 8F (-13.3C) and a couple in the low teens.   A number of citrus survived, a couple died.  At the moment I'm swamped, it's the harvest season and I'm busy picking and preserving stuff, but when I have time I'll consult my records and give a detailed update.

Briefly though, survivors were Yuzu, Citrumelo, the Thomasville citrangequat from Mackenzie farms, Sudachi  and the sole-survivor Changsha discussed above.  All on flying dragon rootstock.  Also surviving was the Thomasville seedling on it s own roots growing out of a patch of Lingonberries, which seem to protect the roots.

Dead were Kabosu on unknown rootstock, and the Changsho from Mackenzie farms that I later grafted onto a FD rootstock.

The Kabosu actually looked fairly good, so I suspect the rootstock, which was quite dead.  I'd already grafted it onto an FD rootstock, so will retest it whenever the next artic blast comes, along with Ichang lemon (Shangwaun) on PT rootstock and Prague Citsuma, among others.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on August 27, 2018, 12:34:24 PM
Some more posts recovered from

Ben Zumeta
(March 2018 ?)

My best friend from childhood's parents have a lemon tree in their yard in NE Seattle. It's at least 15yrs old and seems quite productive and healthy. He is a lifelong orchardist and vintner though and may have used old farmer magic. terms of the happy lemon in Seattle, beyond good ol farmer magic I would attribute its success to being about 2/3 of the way up a SE facing hill with a house above it to the NW. The bottom of the hill has a grocery store parking lot and large arterial covered in black top, and this undoubtedly radiates heat. It also probably likes the boner view of Mt. Rainier.

Marco Downs

I heard recently that Dave Boehnlein got a Yuzu harvest from a tree he planted in a parking strip in Seattle, no special earth/stone works, but lots of feeding and watering. I haven't seen many posts from him on this forum lately but I know he's pretty approchable. From what I've seen, yuzu and other (semi)hardy citrus can grow leaves just fine, which can be wonderful for cooking, but getting the fruit to ripen can be tricky.

Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on August 27, 2018, 02:47:12 PM
very small Keraji seedling, in ground
( (
it's putting on some leaf growth.

small Yuzu seedling, in ground
( (
this one is in the Yashiro Japanese Garden, Olympia
only gets infrequent watering but seems to be doing quite well, perhaps because there's a pond nearby that raises the level of humidity, and the garden is enclosed on all sides creating a windbreak, and there's lots of nearby shade from plants & trees which helps keep ambient temperatures a little lower than they otherwise would be in the blazing hot summer.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on September 11, 2018, 12:07:07 PM

( (

The Yuzu has put on more growth.

I think the rainy season has started (it began raining heavily yesterday).
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on September 19, 2018, 04:43:27 PM
Little Yuzu seedling planted in the ground is doing well:

( (
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on September 27, 2018, 12:02:10 AM
I decided to cover the little keraji seedling in the ground with a cut transparent plastic water container, as part of an experiment to see if they will be able to survive, or if it would help extend the growing season in this cool climate.

The little keraji seedling has actually put on some noticable growth since being covered with the plastic container. Here it was at the end of August, not having been covered yet:

( (

Here's the transparent plastic container that was put over it:

( ( (

Here it is on September 20, temporarily with the cover off so you can have a clear view:

( (

And now here's another picture taken today (September 26 ) and you can see it's noticably put on even more growth:

( (

Obviously the plastic container coverings are working.

I think it's helping for three reasons.
First of all, the container holds in the humidity. This may not be an issue in the South, but in this climate when it's warm and sunny it also tends to be fairly dry. As temperatures are cooling down, that ironically is also going to contribute to dehydration since as the leaves are warmed by the sun's light they will be slightly warmer than the surrounding air, and when you have an object that's warmer than the surrounding air a drying effect occurs (analogous to freeze drying). That's one of the reasons most trees in the Pacific Northwest are conifers, by the way, with needle-like leaves for maximum passage of air to cool off so they do not become warmer than the air (which tends to be cooler from the air blowing in from the ocean).
The second reason is insulation that helps the wind from carrying away heat (this is somewhat like the windchill effect). It might not sound like much but just a simple plastic layer that prevents the blowing of air through the leaves can help raise effective temperatures by a few degrees. This is important with the cool climate here and the growing season coming to an end.
The last reason is the greenhouse effect. Sun light that enters hits the plant or the ground as is converted to heat. Light can enter through the plastic more easily than heat can leave, so as a result the temperature inside a greenhouse rises while the sun is out. This can be a pretty strong effect. A simple plastic container may not really function as the most effective greenhouse but I suspect temperatures inside the container may be 5 or 6 degrees warmer than the immediate area outside (at least while the sun is out and shining on it). This greenhouse effect is far less effective at keeping temperatures up after dark, but warmer temperatures in the middle of the day can mean a longer growing season for citrus, since temperatures are about now dipping just below what citrus needs to grow in. The season is already beginning to cool off.

The thing to fight in the PNW is cool temperatures (cold-cool), not so much extreme cold events. That's why I think this type of strategy is probably a lot more effective here than it would be in the South.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on September 28, 2018, 04:44:16 PM
Warm sunny day, full sun. September 28, 1:10-1:20 middle of the day. Temperature inside the enclosure around the Satsuma read 104 F on the thermometer. Temperature right outside read 89 F.
Weather service says it is 72 outside. Thermometer inside house read 70 degrees, which was confirmed by the thermostat.
The greenhouse effect in full sun is pretty strong. I'll also mention there is a slim crack around the entire bottom of the enclosure right now (plastic not pulled down tight enough), so there is a small gap where air can get through. It is up against a fence, so that may be making a difference, as the sun warms the fence. Thermometer readings taken at ground level.
The greenhouse effect can be powerful in full sun, even when it's just a thin piece of vinyl plastic sheeting.

I had to open it up and vent it out.
Title: Re: Citrus in the Pacific Northwest
Post by: Isaac-1 on September 30, 2018, 09:49:13 PM
I have read that optimal citrus growth occurs at around 86F
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on October 01, 2018, 02:34:02 AM
I have read that optimal citrus growth occurs at around 86F
Maybe in humid climates like the South.
The Summers on the West Coast (including the PNW) are far too dry for citrus to do well in that heat, the leaves can get kind of baked. I think the optimal temperature range might be closer to 76-83.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on October 02, 2018, 01:28:23 PM

( (

enclosure around Satsuma
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on October 12, 2018, 04:53:11 PM
The Bloomsweet needed a little help to deal with the cooling temperatures

( (
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on October 12, 2018, 05:16:31 PM
various citrus seedlings inside greenhouse
( (

(some of them are cold hardy, others not, just off the top of my head, some of them include keraji, yuzu, pomelo, oroblanco seedlings, and others)
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on October 14, 2018, 08:05:46 PM

( (
I made a measurement ( 3:30 in the afternoon, partial sun at that time), it's about 6 degrees (F) warmer on the inside of the cover than right outside. And the top of the cover is composed of breathable fabric that lets some air through.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on November 12, 2018, 11:26:18 AM
November 12, it's the first day with frost. There's a light frost covering the ground.
It's about 8 degrees colder right now than it is in Seattle.
Title: Re: Citrus in the Pacific Northwest
Post by: Citradia on November 12, 2018, 12:24:44 PM
Are the seedlings going in the ground one day? Are you planning to wait for them to make fruit? Will you build twenty foot tall frames around them to protect from cold so they may make fruit 6-10 years from now? My Changsha seedling is 15 feet tall, protected, and still hasn’t bloomed. If it doesn’t bloom this spring I’m tempted to cut it down, toss my seedlings in pots, and just deal with grafted stuff.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on November 12, 2018, 06:44:14 PM
This is in zone 8, and I don't think any of this would be worth attempting if it was even in zone 7b.
I have read a few reports of non-hardy gardenia varieties occasionally being able to survive around the sound in this region (which seems very encouraging, if true).

As for fruiting, I'm not truly sure if that will happen. Unlike much of the rest of the PNW region further North along the sound, we do get some heat here in the Summer (although it's not a long Summer, and the nights can often still get pretty cool).
The Satsuma is in a cold frame enclosure outside, that's not going to be opened up until April, so surely that's going to be acting as a greenhouse of sorts, giving it the extra heat it needs (at least on clear sunny days).
It's also important to take into consideration that citrus grown from seed (not on rootstock) will be less precocious and take much longer until it begins fruiting, even though I think own-root citrus are more vigorous and hardy in this zone 8 climate. This combined with the shorter growing season and cooler Northerly climate could mean that it could take a very long time before a citrus tree begins fruiting, and the tree might be quite big by the time that happens. That's why I wouldn't necessarily give up on a seed-grown tree just because it's been growing for 10 years.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on December 30, 2018, 07:20:47 PM
A post I found archived on the old Citrus Growers Forum:
Las Palmas Norte
Location: Lantzville, Vancouver Island
23 January, 2014

Been ages since I was on this forum last. Just a quick update on a few in-ground citrus I have in zone 8b Vancouver Island.
Last big freeze was Dec 6 where temps dive bombed to 20°F / -6.7°C. Both Yuzu and Changsha where absolutely fine. 10° Tangerine had it's leaves flag, only to pick up again after that bad night.
Hope everyones citrus is doing great. Belated Happy New Year.
Las Palmas Norte
27 February, 2014

10° Tangerine picked up nicely after the leaf flag back then and has been fine since. Recent wet snow has not fazed any of these either. Mother nature is expected to deliver another blow this weekend with temps down into the low 20's / -5°C on Saturday (Mar.1).
(reference to Ten Degree Tangerine, a yuzu x clementine hybrid)

Location: North Vancouver, BC, Canada
6 June, 2010

Skeeter, Your sisters satsuma - was it a seedling or a cutting? I have heard satsumas are difficult to root (cuttings). I have tried a few different methods - all without success. We didn't get much frost this winter and NO snow ! - only a few frosty nights in December. My (in ground) satsuma, Changsha and for the first time my Juanita are in bloom now - meyer lemons have finished blooming Smile


Gregn, citrus enthusiast. North Vancouver Canada. USDA zone 8. I grow In-ground citrus, Palms and bananas. Also have container citrus
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on February 04, 2019, 04:55:22 AM
We're getting snow for the first time this Winter, and temperatures are expected to get down to 19 F two days from now.
Title: Re: Citrus in the Pacific Northwest
Post by: Citradia on February 04, 2019, 10:07:54 AM
Good luck with the coming cold!
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on February 04, 2019, 05:51:58 PM

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Interestingly the water inside the gallon water containers on the ground has still not frozen, even though the containers are covered in snow. However the top layer of some exposed puddles of water have frozen.
Title: Re: Citrus in the Pacific Northwest
Post by: Citradia on February 04, 2019, 06:20:11 PM
Oh my goodness; the tree in photo #2 that isn’t covered has a lot of brown branches. What is it and how long have those branches been dead? Is the base of the trunk cracked? 
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on February 04, 2019, 06:26:40 PM
Oh my goodness; the tree in photo #2 that isn’t covered has a lot of brown branches. What is it and how long have those branches been dead?
I believe it's a MIC, and those brown branches were already dead from being planted out too early in March after growing very well inside a warm grow enclosure inside. Even though it never went below freezing during March, I learned that citrus growing in warm conditions inside cannot tolerate a sudden transition to cold outside. It will cause die-back, even though that hardy citrus may have been easily able to handle those temperatures otherwise.
Title: Re: Citrus in the Pacific Northwest
Post by: Citradia on February 05, 2019, 06:56:38 AM
That’s true. Why didn’t you prune the dead wood last year during growing season? What does MIC stand for?
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on February 05, 2019, 01:35:42 PM
Saturday it's expected to go down to 16 degrees.
Which is pretty typical to have at least one night in the Winter where it gets down to 15 or 16.

The reason for the temperature lows is that cold air is blowing down from the North through the Puget Sound.

The winds are not really extending all the way south, so Portland is not going to be as cold, even though it is a little more landlocked.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on February 08, 2019, 04:30:40 AM
The latest weather forecast predicts it could get down to 12 degrees early morning Sunday.
I don't think it will get all the way down that cold, but that seems like an unusually low temperature point for a typical Winter.

Most of the citrus should just barely be able to survive it (if all the research I've done turns out to be correct).

So far all the leaves on the citrus look okay. Not really good, but not terrible. A few of the hardy varieties that do not have quite as much hardiness as the others are covered.
Title: Re: Citrus in the Pacific Northwest
Post by: jim VH on February 08, 2019, 11:19:44 AM
Yes, so far I've only seen 21F(-6C) at my location in the Portland area.  This won't damage the hardier citrus, but I did close up the Satsuma shelters.  Saturday night it may hit 18F(-7.8C), and colder temperatures may be possible if cold continental air starts pouring through the Columbia river Gorge accompanied by any overnight clearing that may occur.  That's cold enough to damage-or even kill- Satsumas, so In that case I'll run the Christmas tree lights in the Satsuma shelters.
All leaves on the unprotected Citrus look good, except the Ichang Lemon (Shangyuan variety)   Given this, I suspect it may not be as hardy as the 5-10F sometimes claimed for it, though I doubt it will die in the present event.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on February 08, 2019, 06:29:05 PM
It's snowing heavily. Temperature is only 33 though.

Yuzu, with the enclosure covering the Bloomsweet in the background:
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The cover has bent over due to the weight of the snow.
It's on the south facing side of the house in a warmer spot protected from wind.

Dunstan citrumelo in snow:
( (
Title: Re: Citrus in the Pacific Northwest
Post by: jim VH on February 09, 2019, 10:44:06 AM
My brother tells me it's predicted to get down to 12F (-11.1C) at his place in Tacoma overnight Saturday, much colder than Portland.  If you do get down to 12F tonight at your location,the Yuzu and maybe the Citrumelo will probably defoliate.  Mine did when they were that young.  But-at least if they are on a flying Dragon or PT rootstock- they should survive.  I've found that other rootstocks are a bit more problematical in the extended Freezes in the PNW.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on February 10, 2019, 01:25:34 AM
The forecast is still on for it to hit 12 degrees at about 6:30 am in the morning.
It's still 27 degrees right now at 10:20 pm. I'm going to go out there with some hot water containers very early in a couple of hours.

Looks like this will be the only really low point this week, according to the forecast.

The good news is the snow is deep enough to mostly cover the small plants, which should provide some degree of insulation as the temperature suddenly dips.

There wasn't snow on the ground at all in December or January.

Update: 1:00 am, 20 degrees, just checked on the gallon water containers outside and they are still liquid, cold but not even any ice in them. They were on the ground under the covering, insulated by a thick layer of snow. Going to warm them up right now.
Title: Re: Citrus in the Pacific Northwest
Post by: TooFarNorth on February 10, 2019, 07:06:41 AM
Good luck with your trees.  Hopefully the snow will provide a lot of protection for them and the hot water also.  Thankfully, this winter, so far we have only had to deal with the mid 20's.  Best of luck.

Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on February 10, 2019, 03:49:54 PM
When I went out there last night I noticed the smaller uncovered plants were all bent down into the snow. Apparently the snow kept accumulating on the leaves and stuck there and froze, weighing the plant down. I hope this didn't permanently bend or break any branches. The leaves on the citrumelo and ten degree, which were weighed down in ice do not look very good, Yuzu doesn't look too terrible, but that's probably because it was more bushy and the snow just formed a ball around it.
I don't know how low the temperature actually dropped in the yard, but I measured 24 °F right outside the doorstep at 3:00 (very early morning).
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on February 10, 2019, 05:50:28 PM
Newspaper article:
The South Sound is digging out from the biggest snowstorm in a decade Saturday morning. Now, it’s going to get cold.
The mercury is predicted to drop to 17 degrees on Sunday in Olympia, according to the National Weather Service.
At least 10 inches of snow fell overnight in Olympia, according to the Weather Service.

A winter storm warning is in effect through Saturday afternoon in Puget Sound. Winds are forecast to reach 16 miles per hour Saturday with gusts as high as 28 miles per hour in central Thurston County.

Puget Sound Energy was reporting more than 400 customers without power as of 3 p.m. on Saturday.

Mother Nature will not be cooperating in snow removal. Temperatures will stay below freezing all weekend, the Weather Service said Saturday.

If snow should melt during the day, it will undoubtedly turn to ice over night. Temperatures are forecast to get just a handful of degrees above freezing all week. Friday should be the warmest day of the week with a high of 39 degrees.
After Sunday’s dip into the teens, lows will be will be in the 20s all week.
Interstate 90 over Snoqualmie Pass is open to vehicles with traction tires or chains.
However, I-90 was closed in both directions from six miles east of Ellensburg to Vantage as of 6:30 a.m. Saturday. Tractor-trailer spin-outs are blocking the roadway and drifting snow is causing poor visibility. WSDOT could not provide an estimated time to reopen the highway.

Flights into and out of Seattle-Tacoma International Airport are affected by the storm. Alaska Airlines is allowing passengers to change their travel plans through Sunday. Passengers should check with individual airlines for the latest flight information.

Officials from nearly every public safety agency are warning about the dangers of the current weather. Deep snow, slick roads, winds and extreme cold can make for a deadly combination. They urge citizens to travel only if necessary.

The low temperatures also make for dangerous conditions for the region’s homeless population as well as anyone who might lose power during the prolonged cold period.

Heavy snow is weighing down tree limbs which can snap off without warning. Trees have been falling during the night around the region. (
Title: Re: Citrus in the Pacific Northwest
Post by: kumin on February 10, 2019, 05:56:03 PM
Thanks for the post. Providing the weight of the snow doesn't cause damage, snow per usually protective against low air temperatures. Growth above snow on the other hand can be very vulnerable, depending on atmospheric conditions. This event should be informative, after there's a chance to evaluate the outcome and subsequent recovery. Wind is a mixed bag, it contributes to desiccation on one hand, but also contributes to temperature uniformity helping to prevent super-cold air accumulation in low lying areas.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on February 11, 2019, 05:16:24 PM
It's essentially a snowstorm. About 13 or 14 inches piled up so far. Difficult for anyone to go anywhere. There hasn't been this much snow in a decade. Like a ski resort. The temperatures aren't really that extremely low though and the forecast says the lowest it will dip down to in the next ten days is 24, but mostly the nights will be in the low 30s.

I'm going to build a big snowman.
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on February 16, 2019, 05:33:11 PM
Here's a picture of the Yuzu. It was completely covered in snow, but the temperatures did not go too low. The layer of snow on the ground was 16 inches deep at one point, but it has now been rapidly melting, in part because there has been some light drizzling of rain. It still has its leaves and doesn't look too terrible.

( (
Title: Re: Citrus in the Pacific Northwest
Post by: SoCal2warm on February 18, 2019, 06:00:41 AM
Large lemon tree growing, and fruiting, with protection, in Eugene, Oregon

Jan Spencer may have the most unique pet around. It’s a lemon tree.
This relationship isn’t the usual gardener/plant thing. No, he really has an affinity for this tree. In turn, the tree provides Spencer with a huge bounty of delicious lemons every year from Christmas to spring.
“I don’t get into the supernatural realm too much,” Spencer says, “but I think the lemon tree likes it here.”
Here in early February, the ripening lemons on the bushy tree are a sight to behold. Neighbors are welcome to pick fruit, and Spencer bikes around his River Road neighborhood in west Eugene stashing lemons in the lending library boxes neighbors have in their front yards.
These days, along with books, kids might find fresh lemons, the likes of which they won’t see in grocery stores. Spencer’s lemons also are occasionally sold at farmers’ markets.
His lemon tree wouldn’t raise an eyebrow in Southern California. But in Eugene?
And it’s not the tiny, indoor mini-pot kind of citrus. The tree stands 7 feet high and 25 feet in circumference. Can this really happen so far north?

Spencer is a local champion of suburban permaculture.
Cold weather protection
Here’s how the story began.
“The tree started life in Santa Clara (in Eugene), planted by a good friend’s dad,” he explains. “I always noticed that tree when I visited and marveled at it.”

The tree’s original planter, Phil Damron, was getting into his late 80s, and his wife, Jane, didn’t like how he had to go out so much in cold weather to put protection around it.
That led to Spencer “adopting” the tree eight years ago.
“For years we thought it was a Meyer lemon, but apparently it’s not,” he says. Whatever the variety, he’s delighted by its results.
“I replanted it out by the driveway in front of a south-facing wall, where I can gaze at it from the house,” he says. “But here’s the deal,” he continues. “It really is too cold for a lemon tree here. If you want one you need to protect it from the cold.”
Would that all pets get treated this well. “I watch the thermometer all the time during winter,” Spencer says. “Mid-20s is not kind to a lemon tree.”
He constructed a PVC pipe frame around the tree, over which he can throw blankets, sleeping bags, rugs and any other convenient protective cover.
He also puts a bubble pack around the tree up to 4 feet thick. The blankets drape down over the sides so no cold air can get in.

At times he’ll use an electric space heater, especially on nights temperatures dip into the low 20s. It takes up to 45 minutes of hard labor on those cold nights to sling all the protecting covers over the plastic pipe framework.
On warmer days, Spencer partially removes the tree’s protective layers for maximum sunlight exposure.
But typically, the tree needs covering only a few days a week during winter.
The over-arching lesson here is that you can grow anything anywhere if you have the resolve, passion and commitment to do it.

The Register-Guard, 2018 (