Dekopon Log Zone 8b/9a North Florida

[LaCasaVerde]

Hi all.  After reading Millets postings and scant others on the net it became apparent to me the need for more actual information on growing this particular  citrus. Id like to preface this log by saying that Im not a pro citrus grower. Im a backyard citrus student of 15 years. Many of those years spent trolling the net looking for information when I got into a bind.  Hopefully this log will give someone else some new ideas.  Please feel free to add to, correct or nullify any information on this log for the benefit of others.

This post starts recording information on Shiranui/Dekopon performance for others  in North Florida or those in similar grow zones.  There are  2 test plants : First planted last year  in November 2015 to test conventional wisdom and the second in June of this year. Both are in ground. I am  currently building a greenhouse around them and several other citrus trees which will share the space.

Background Information:
Pensacola Florida zone 8b/9a (depending where you live. I happen to be in on 9a by five miles). Water table 3 feet. Sandy soil. Full sun at 8 or more per day. Well water irrigation- ph 5.5 steady.  Climate- hot humid hot then 3 months of winter which have included 8 sub 32 events lowest at 27 degrees. Up two three weeks of constant 38-50  degrees  night lows. Mild winter last year.
The first Dekopon was planted in November  15 at 3 feet tall and was covered in agribon frost cloth  and  one string of Christmas lights when freezing temps were present . Spring brought flower and 39 set fruit. No fruit drop through summer and very little if any leaf drop.  Unusual for fruit set  considering time between transplant and fruit set. Interesting note adjacent Navel orange and blood orange trees suffered rust mite  outbreaks on all fruit which has been controlled but no evidence of mites or  russeting on any Dekopon fruit.  Citrus red mite  outbreak immediatly after application of Mach 2.0 mid summer. Citrus leaf miner damage  through summer to new flushes. Following a photo out of Japan I supported each limb with twine which has been very succesfull now that the fruit are starting to turn color and size up. Current size 5 feet with 4 foot spread.
The second dekopon was transplanted out of pot at 3 feet and has languished. Slight yellowing of leaves, no new growth. Evidencing transplant shock.  Neither growing or dying.

Fertilized Deko1 March May July- 1 cup citrus ferts. No fertilizer on Deko2  other than 1/4 strength fish emulsion foliar to leaves and 1/2 stength fish emulsion to base in August to counter what I initially thought was inadequate nitrogen.

Tomorrow Im going to post pictures of the plants and methods I used to limb support Deko1. See you tomorrow!

[LaCasaVerde]

Deko1 pictures showing fruit and plant size. By suspending aircraft cable above the Dekopon I was able to use twine and tie up all the fruiting branches. This was done in May. So far this has provided excellent  limb support and has provided the tree with stabilization in high wind days.  I have kept the original tie off stakes at the base as well to limit the movement.  After first harvest Ill remove to strengthen root system. If it had not been done Im sure there would be limb breakage at this point. 
Tonight and tomorrow lows are predicted to be 50 so Im curious if this will fasten color up of the fruit. I plant to taste test fruit at one month intervals starting Dec 15. 

Due to heavy fruit set Im wondering if this means little or no fruit set next year. Im not sure if Dekopon is alternate bearing.Anyone know?

Also interested to see if Ponkan and Minneola tangerines in proximity will have caused seeds in the current Dekopon fruit. There are also two large Meyers lemons in proximity as well.. hmm.

Im going to graft a dekopon branch this spring to a Minneola tangerine to see if it provides pollination. Not sure it will work.

It seems also that by the time the fruit is mature the Dekopon must be flowering again at the same time? Is so where and when should pruning begin. Currently it seems there is adequate light penetration. Any advice?

As I have not thinned the fruit I noticed no fruit size diminishment. Those fruit clustered together seem not to be affected other than additioan limb weight. I will thin next year and compare size.







[LaCasaVerde]

Twine was used for limb support. By tying large loop knot,  the limbs move freely and there is no damage after 5 months.  My satsumas pull limbs all the way to the ground.. By placing the cable several feet above the center of the plant I was able to tie off all sides of the Dekopon. The use cable for this main support as it will not break.. I know as an Owari I used a simillar set up on did.  Here is a way Ive found very successfull for this on other plants in the garden if you dont have a greenhouse:

Take 1 10foot 1 5/8 fence rail and cut into 2 foot sections with a recip saw. Then hammer these into the ground. Then slide a 1 3/8 fence rail post into this sleeve at desired height suspend cable across this  over plant.  This also works very well with 1 inch pvc pipe cold frames for large citrus trees Just use a smaller size pipe diameter- 1 3/8 I believe..  Just insert you PVC pipe into the sleeve
Ill include cold frame pics for others desiring cold frame ideas  as well for the heck of it.

[LaCasaVerde]

Last winter I covered Deko1 with Agribon fabric over a cold frame. I  used set cut off  4x4 posts with a metal fence rail frame around it as seen in the other included cold frame pics of other plants in the garden . It is and was a very tedious set and dismantel pre and post winter . So after experimenting with  numerous designes  Ive come up wi h a very easy and sturdy cold frame that is easily expandable. affordable and quick.  It leaves very little damage to yards and can be used for larger trees as well.  Ill do a complete photo shoot but first to start is the foundation. I had planned to use this cold frame sleeve method for the dekopon but decided to build a large greenhouse around it instead. So Ill use it for a test frame on a hamlin. Here is how to set the base of a pvc or metal pile cold frame in your yard. Easy and quick:










The pvc pipe I have inserted into the sleeve of course would be cut to the height  of your plant. Once all four posts have been inserted then use a 3 way pvc fitting and begin your horizontal runs. Do not glue- rather use screws to secure by driling though fitting into vertical and horizontal runs. I used tek screws. This way you can dissassemble and reuse following year.
The best part about the base sleeve  in  is that it can be left inground over the summer or pulled leaving a small hole that fills itself in it seems.

[LaCasaVerde]

Here is how this set up evolved. The following few pics show different styles. Ive mixed wood, pvc and pipe together to come up with many different designs for cold frames.  If anyone is interested Ill post several more designs. Anyway, the idea here was to find a set up that could be used over and over again with the least amount if time consumed.  The below pictures show designs Im scraping due to time but still are great frames! . The cut off 4x4 posts are left in the ground year around and then the frames added in the fall. Make sure to oversize the spacing of the posts to the tree so that 3 or four years can go by before you have to reset the posts . I wish I knew this earlier as it would have saved me a huge amount of time. Use snap clamps to adhear the poly to the frame.

Anyway these frames take too long for me to set up. Thus the sleeve cold frame foundation shown in earlier post. The top of the frame would be the same design of the these other ones but without the wood posts in the ground making the set up and dismantel very fast.

[LaCasaVerde]

Here is a summary of the basic facts Ive collected and observed so far.

Dekopon also known as Shiranui, Hallabong does not like wet feet. Grown in Brazil South Korea (hallabong) and Japan primarily. Supposedly acid is reduced by storing the fruit for 20-30 days - I have seached in vain for the actuall temperatures these are stored at So half will go into the botton veggie drawer of the fridge to see what happens.  Harvest time is March though another grower here in Tallahasee Florida says that they are ripe January.  Pruned like a peach. Cold hardiness of the plant better than the fruit-. All fall winter and spring Deko1 was open to the elements here in Pensacola and breezed through many 36  plus nights uncovered as well as many days with highs in the 50s. There was no adverse leaf damage. In Japan these are harvested in a controlled warm temp setting in late winter.  I plan to test   that colder temps with lack of irrigation toward December first and on will increase brix of the fruit and hasten fruit to ripen here sooner. It seems to me that if the Dekopon are harvested in a warm climate controlled envirnment the acid is not allowed to decrease in ratio to the sugar content naturally. Noticed in following link https://shizuokagourmet.com/2012/03/28/dekopon-oranges-producer-nobuhiko-onuma/ that the trees pictured are outdoors and are harvested outdoors.

Okitsu in Shizuoka Prefecture is nationally famous for its citrus fruits thanks to an ideal sun exposure and wide differences of temperature between day and night contributing to an extraordinary sweetness of the fruit". Comparing temps many areas of North Florida and panhandle area along gulf coast are very similar in the day night temp swings. Pensacola actually has a warmer  late winter than Okitsu perhaps providing this area a stronger survivability for the Dekopon.

California seems to be prime for the Sumo mandarin. Florida though has no information other than that the Dekopon has produced poor results in central and south florida due to a lack of adequate temp swings (hot to cold) from day to night. North Florida as well as the entire gulfcoast to Texas is known to be prime Satsuma territory because it is cooler and has more of a dinural fall and winter climate . Ponkan does well here so Im hoping that it will shine in the Dekopon.

[LaCasaVerde]

Notice the Ponkan neck is very similar to the Dekopon. My ponkan has not started to turn color yet both shares the fruit shape and pebbly skin. Come to think of it the Ponkan as well did not suffer from rust mites this season. All my other tress did . Neem oil 1 table spoon to quarter gallon water sprayed in the eve after the heat of the sun stopped the russet mites for me on the fruit anyway.
Dekopon first then Ponkan:





Has anyone ever had russet mites on their the Dekopon or Ponkan?

[Millet]

LCV your Dekopon posts are again another excellent post.   I also have two Dekopon trees, one in the ground (3 years old) and one in a 13 gallon container.  The in ground tree is approximately the same size as the tree in your very first picture. It has been grown all of its life in a large greenhouse, and lit with a 250 Watt Metal Halide light from dust to 10:00 PM during the winter months, promoting extra flushes of growth.  This past spring was the tree's first real flowering and setting of fruit. For the first cropping the tree set 13 fruit, and like yours, all 13 have remained.  Not one was discarded.  As with your tree, the fruit on my in ground tree are also just now starting to turn yellow.  All fruit, except for one, are large, typical to the variety.  My second tree has always been grown as a container plant.  It is the same age as the in ground tree, only smaller in size (2'ft), and is producing 7 fruit.   My guess is that I am growing at much the same temperatures and humidity as central Florida.  The lowest temperature during the winter months inside the greenhouse is 50-F.    I have not given any support to any of the branches on either tree.  The trees seem to produce branches strong enough to support the weight of the fruit. I'll keep an eye on the tree as it grows into a large tree.  I have planed to let the fruit remain hanging on the tree, until late February or early March.  Probably will pick a first fruit in late February for a taste test.  If sweet enough,  I doubt that I will store them 20 or so days to sweeten up.  I'll just have to see.  Some observations about Dekopon:  No leaf drop, not bothered much by insects, so far zero fruit drop, more or less a trouble free tree.  When searching the Internet for Dekopon information, I also came accross the same web site that you posted above.  Would be nice to visit the Dekopon growing areas of Japan, and talk to the growers of the fruit, as they have the most experience of any in the world about Dekopon. Further, as with your trees, I also have an in ground Ponkan mandarin.  It has too many fruit to count, and so far none have started to turn color.  Perhaps I should have thinned them out some, in order to get fruit of larger size, not sure, as they are still growing.  BTW, Mr. Texas (Houston area), who also posts on this site, has build small greenhouse around some of his trees to protect from winter cold. Thanks for sharing.- Millet

[LaCasaVerde]

Thank you Millet.

Lets share future tests with the fruit. It would be neat for others to see an West vs East comparison. Thank you for your min temps for this plant as well. Im going to keep the Dekopon unheated until Sub 32 weather this year. The greenhouse is 14x28 and is placed North South due to my location. Morning heat collection is more important as freezing temps very very rarely persist past 8am here (knock on wood).  As a curiosity- your Dekopon is lighted in the eve to increase vegitative growth flushes. When I was in college I grew a small garden and maintained a fruiting orange tree in a one bedroom second story apartment. I used metal halide for the vegatative states as that light wave length is more benificial. However, sodium halide I used for fruiting to harvest as it promoted fruit set and development. In my citrus currently after my plants set fruit there is a noticabley slower metabolism in the plant for vegitative growth (pronounced with heavy fruit set).  Then towards the end of the second two thirds they resume a slower later season flush. Im not sure when you light you plants ie start using additional lighting due to the days shortening but I would consider intermixing sodium halide as it promoted fruit set and development as I remember. Would this make sense in a greenhouse sections where plants were in fruit development late season or is it irrelevant?

What a trip that would be. Visiting the source growers for advice. One particular question Id have- At what temp are these fruit stored at post harvest? And why are fungicides to prevantly used there...every month? Funny- I actually tried to blow up a picture that showed one of these cooling rooms used for Dekopon storage and could not make out what the temp gauge said. I suppose I can throw these in fridge bottom drawers as the kieffer pears will have vacated that space by then.

[LaCasaVerde]

The last few nights have tested 35 degrees in the early mornings. The dekopon have all turned yellow. No adverse affects to the fruit or leaves with the cold weather.   Cold fronts here last a few nights on average returning again to the low 50s at night and 70s during the day. I have to keep reminding myself not to pick the fruit until January.  Unlike other citrus from what Ive read - dekopon is best left on the tree even as it appears ripe. Nevertheless picking one wouldnt hurt!!

I picked an interior fruit. WOW... very sweet, very juicy with a subtle  acidic side to it. Honestly I didnt expect it to be that good. It was better than a good  Owari with melting flesh.  My wife wanted another... and if I didnt resist I would have. Very good.  Almost wondering if mid January the fruit would be over ripe and on decline.  Next fruit test Dec 15

October November conditons have been dry. Irrigation at once per week 10 gallons.  No ferts. Fruit has some signs of rust mite damage. This was not apparent while green but is more visable now that the color has changed.

 Anyone know the rules on sending citrus seeds out of Florida?





Of interest ..I removed 12 seeds from the fruit. Obviously there has been cross pollination from the other citrus. 

[Tom]

Congratulations , sounds like it is going to be very good for you in Pensacola ! I could not wait until December 12 for the next taste test. Maybe a week or 10 days with the cool nights we are having ! Tom

[bsbullie]

While I dont know the source/location of the fruit, Whole Foods in South Florida has had/sold Florida grown Shiranui in late January and February the last w years.  The fruit have been large to extremely large in size, with the fruit easily weighing in up to 1.5 lbs. plus each.  The quality has been very good to excellent for a Florida grown mandarin/tangerine/orange (sorry but California is King when it comes to most citrus in the United States.  Yes, Florida grows decent lemons, limes and grapefruit and there is some excellent grapefruit coming out if Texas but I will take a Cali grown citrus any day).

Despite the post above, the Shiranui does produce in South Florida.   Does it suffer if we dont get any cold fronts during finishing stages, yes, but so does any orange, grapefruit, pomelo or tangerine grown in this area.

The California grown "Sumo" follow usually in March.

I have never found a single seed in any of the Florida or  ali grown Shiranui and I have  consumed many many pounds of these fruits over the last few years.

[LaCasaVerde]

Congratulations , sounds like it is going to be very good for you in Pensacola ! I could not wait until December 12 for the next taste test. Maybe a week or 10 days with the cool nights we are having ! Tom

Thanks Tom. How are yours going there?Ripe yet?  It seems for me anyway all my satsumas are late ripening this year. Somewhat sweet but still all 50 percent yellow to green ratio. Perhaps a few more weeks.

[LaCasaVerde]

While I dont know the source/location of the fruit, Whole Foods in South Florida has had/sold Florida grown Shiranui in late January and February the last w years.  The fruit have been large to extremely large in size, with the fruit easily weighing in up to 1.5 lbs. plus each.  The quality has been very good to excellent for a Florida grown mandarin/tangerine/orange (sorry but California is King when it comes to most citrus in the United States.  Yes, Florida grows decent lemons, limes and grapefruit and there is some excellent grapefruit coming out if Texas but I will take a Cali grown citrus any day).

Despite the post above, the Shiranui does produce in South Florida.   Does it suffer if we dont get any cold fronts during finishing stages, yes, but so does any orange, grapefruit, pomelo or tangerine grown in this area.


The California grown "Sumo" follow usually in March.

I have never found a single seed in any of the Florida or  ali grown Shiranui and I have  consumed many many pounds of these fruits over the last few years.

Seedless unless cross pollinated I assume. I thought the Dekopon would be near seedless (like 1 maybe) . I suppose  Dekopon are grown away from other pollinators or perhaps netted in order to get that seedless state.

  My Owari are the same- a seed in every segment.  I watched a video of a lady that netted her citrus and achieved seedlessness in all her varieghtys. She mention in the clip though that her fruit size was diminished slightly... The Dekopon I picked was softball size....

[Tom]

I have some big trees in ground, Owari I think, that are still at least 1/2 green and huge fruit for a satsuma ! They are also very seedy. They are getting a little more flavor. My Kishu in ground is still my favorite but I've had some very good Owari and Xie Shan too. These trees are still very small. Most Meyer Lemon fruit are yellowing very nicely. Kishu still completely seedless ! Thanks for asking. Tom

[LaCasaVerde]

hmm. Xie Shan I have as well. Another grower here in Pensacola said his xie shan was the cold hardiest of the bunch he had. We had 1 19 degree winter night in 14 that killed a lot of citrus. His xie shan was  not protected at all and was unfazed.  Montgomery.... Are you protecting yours in the winter? Or no? Id like to stop the cold framing here if possible on the satsumas/mandarins  anyway.

After your post I looked up kishu. Looks like a cutie sold in the store but smaller. How has its cold hardiness been for you there?

[Tom]

I do protect all my citrus way up here in Montgomery. I don't do it all the time but we have enough bad weather at times that I have to during critical times. Here and where you are we can have 80* temps at Christmas and a cold snap 2 weeks later with a hard freeze and even have 2 or 3 days without reaching temps above freezing. That's devastating imo and I'm too old to risk it unnecessarily !! I don't want to start over.

The Kishu is like a very small cutie from the grocery store. I don't know anything about it being unusually cold hardy. One thing that got me interested in trying to grow my own citrus is the huge variability between different fruit at different times of the year. Grapes, citrus, watermelon, cantaloupe and on and on. There is one honeydew called king of the west I think, it's fantastic. It usually available for about 1 month. Most honeydew don't do anything for me.  I've had two satsumas from the same tree [of mine] taste different and they were both very good.

Another time I had the best manderine I've ever had. Absolutely incredible. A year or two later the fruit on the same tree was only ordinary at best. Not my tree but one I watch carefully !!

I'm unsure about the cold hardiness of Xie Shan but I've had some very good fruit from my small tree and others that were bigger trees. Bigger trees really do usually make for better fruit and are usually more cold hardy too but..... You might enjoy a Juanita tangerine and the story but I'd be careful with it while it's young. The mother tree is supposed to have survived 0 degrees in South Carolina long ago unprotected but probably in a favorable microclimate. The mother tree recently died. It was too large to protect and it did not survive 3 days and nights in a row continuous below freezing. It's seedy but has good flavor. The lady the tree was named after died the same winter !!

I must add , everybody says Meyer Lemon is grown by more homeowners than any other citrus. It's not my favorite and the thorns tear me to pieces but everybody [99%] love the fruit and it's very hardy. Yes, it's my biggest citrus in ground, not grafted but on it's own rootstock and I still trim it back and cover it during bad cold snaps.

Hang on and have a great time but I'd be careful about going completely without protection and absolutely protect your young trees during dangerous conditions !!

Tom

[LaCasaVerde]

Thank you Tom for the info. Ill follow up on the Juanita Tangerine. Im always looking for another citrus   Very interesting story from what Ive read so far over the last few mins.

As to the fun..Yes it has turned from and interest to a real enjoyment. Though I find myself making more and more work as I too dont want to start over. Now if we could only find an everbearing sweet orange or mandarin/satsuma for year around fruit!

 

[Tom]

Maybe a year ago Millet wrote that with a Valencia tree and a Navel orange tree you could in theory have citrus 12 months a year..... if I was in Florida I think I'd try that and I might even try it way up here.

Do you know darkman? He is very knowledgeable and very close to you but I haven't heard from him for a while. Please tell him hello for me.

Tom

[LaCasaVerde]

Yes, I spoke with Darkman the other day by phone. We shared some points. It was his reference to xie shan hardiness that I mentioned earlier. He was adamant about the xie shan being far more cold tolerant unfazed with three days sub 32 and nights in the teens. His xie shan from what i can remember was 4-5 feet tall and wide and is currently laden with fruit.

I too have thought about the Valencia Navel combo -Would be better though with a Hamlin for early November december oranges, Navel for Ja--Feb oranges and Valancia for early summer. Perhaps a three way graft to a single tree would do it. Not sure if this is possible but should be. I dont see why they wouldnt take .

I will pass on the hello no problem!

[Millet]

My in ground 4 year old grafted Dekopon tree set 15 fruit this year.  Most all were set on the same side of the tree causing the tree to lean hard in that direction.  It was necessary to support the tree to return it to standing position.  The fruit are huge, and presently beginning to turn orange.  The temperatures in the greenhouse has been running 75+- day, and 50 night.  It produced one fruit last year that I picked to soon.  The taste was good, but clearly not ready. I'lll wait until at least January before tring this years crop. I also have a 4 year old Dekopon growing in a 13 gallon air root pruning container.  Its fruit started to color up about a  month ago.   My understanding is that a Dekopon tree needs to be thinned out to allow sunlight to penetrate throughout the foliage, in a manner  much like a peach tree in order for the tree to continue to well.  I'm not exactly sure what that means, but I guess I'll find out. My Ponkan tree is absolutely loaded, with too many fruit to count.  Unfortunately, because ponkan is an alternate bearing variety, next year being the off year should only provide a fruit or two.   I've read that if the on year crop is thinned way back so that the tree does not expand so much energy, then one can expect a crop on the following off year.  However, I decided to take the big crop this year, and live with what happens in 2017..  This is the first year my in ground Valentine Pummelo set fruit (just 2) so I'm looking forward to a much larger crop next year.   I also have an older Valentine growing in a 20 gallon container that stated fruiting several years back.  If you never tasted a Valentine Pummelo your really missing something. Lastly, LaCasaVerde, tell Darkman Millet said to get over to this web site and at least say hello.  Tom, Darkman, and I all attended the Southeast Citrus Expo together the year it was held in Alabama, which gave us an opportunity to know each other. - Millet

[LaCasaVerde]

My in ground 4 year old grafted Dekopon tree set 15 fruit this year.  Most all were set on the same side of the tree causing the tree to lean hard in that direction.  It was necessary to support the tree to return it to standing position.  The fruit are huge, and presently beginning to turn orange.  The temperatures in the greenhouse has been running 75+- day, and 50 night.  It produced one fruit last year that I picked to soon.  The taste was good, but clearly not ready. I'lll wait until at least January before tring this years crop. I also have a 4 year old Dekopon growing in a 13 gallon air root pruning container.  Its fruit started to color up about a  month ago.   My understanding is that a Dekopon tree needs to be thinned out to allow sunlight to penetrate throughout the foliage, in a manner  much like a peach tree in order for the tree to continue to well.  I'm not exactly sure what that means, but I guess I'll find out. My Ponkan tree is absolutely loaded, with too many fruit to count.  Unfortunately, because ponkan is an alternate bearing variety, next year being the off year should only provide a fruit or two.   I've read that if the on year crop is thinned way back so that the tree does not expand so much energy, then one can expect a crop on the following off year.  However, I decided to take the big crop this year, and live with what happens in 2017..  This is the first year my in ground Valentine Pummelo set fruit (just 2) so I'm looking forward to a much larger crop next year.   I also have an older Valentine growing in a 20 gallon container that stated fruiting several years back.  If you never tasted a Valentine Pummelo your really missing something. Lastly, LaCasaVerde, tell Darkman Millet said to get over to this web site and at least say hello.  Tom, Darkman, and I all attended the Southeast Citrus Expo together the year it was held in Alabama, which gave us an opportunity to know each other. - Millet

Happy Thanksgiving!
Im in off year for the Ponkan with 2 fruit. It is alternate bearing.  I watched a video on pruning the Dekopon the other night and came across an interesting side note. It appears the Dekopons fruit quality is directly connected to the amount of rain/irrigation ts receives during the summer.  I cross referenced this found a correlation to the fruits sweetness. I have a sandy soil with water table at 3-4 feet. The root system must then have a constant supply of water if it goes down that far... Id say something is working because the fruit Isampled the other day was outstanding. Ill include some pics next post.
Im also going to learn about this Valentine Pummelo you mentioned. I would definitely add one to the collection if it is as good as you say. Ive never tasted one. Are they sweet? Ive noticed in other posts that you top height was 11 feet in the greenhouse. Im assuming your planting dwarf citrus?
 I just finished mine here. Built it myself over a year. It is LaCasaVerde by name and is an Orangarie by design 16 feet peak gable with both sides completly roll up. When closed ventilated with intake and exhaust to pull all are at one min interval. Unlike others, Ive designed it to be flooded by 1000 gallons of water, not for irrigation but for evening heat. Ive found in another greenhouse I built that 3 ibc water totes heated in the greenhouse then released on the floor provided 5-8  degrees of heat rise but more importanlty provided it uniformly accross the greenhouse andacted as a temperature curve buffer dramatically slowing heat loss at night. The the next day the solar gain in the green house is absorbed faster into the ground and released the following night. This process is only done during extreme cold weather events usually only lasting 3-4 days here at most. Once warmer air moves in the side walls can be raised and humidity released allowing the greenhouse to dry out again. In this one I have inground Hamlin,Blood, 2 Deko and a Navel/ As well as potted Bananas, Cherries and Papayas. Ive found that the high wall design is much more efficient and practical as my citrus are not dwarfs and will fill it in a few years.
 I will pass on the invite to Darkman. He did mention that you both were in Alabama during our conversation. Reminds me that I need to trade a Dekopon fruit fro one of his xie shan as Id like to taste. My xie shan is too you still.
Also - you mentioned your Dekopon leaning. I stake and tie off all my citrus  for the first few years. This way they dont lean when laden with fruit initially. Ive found that after a kimbrough I has started leaning one direction with fruit, the root system contiued to grow compensating. When I did decide to stake it and tie of the trunk it was more difficult to correct.

[LaCasaVerde]

[LaCasaVerde]

Both sides roll up 8 feet. Side walls measure 10 feet tall. In zone 9a necessary to vent all heat as the green  house will be covered year around.

[LaCasaVerde]

Initially when I started researching Dekopon cultivation techniques I came across several mentions of fungicide being applied on a monthly basis. One grower in Japan provided the following reference from Shizouka Gourmet as the the basic periods of cultivation:

"May: Flowering
July~August: Pruning and thinning the trees to keep only the best fruit. A neck braking work!
From August: regular watering
About the 20th of November: Each fruit is individually protected with a paper bag. More neck-breaking work!
From January 20th: Harvesting."
Latter the same article-
"Moreover, fungicide has to be spread 12 times a year.
Mr. Onuma told me that he keeps any such fungicide to a minimum and does not use any other agrichemicals"

I speculate either the farmer has to do this to present commerical quality fruit or the plant itself is finiky and suseptable to diseases in this category. Im not interested in commercial quality fruit but have noted that as soon as the fruit changed color rind damage due to either fungus or mites became visable. All my other citrus show mite  damage while fruit is green. Dekopon showed absolutly nothing until it changed color.

Im growing outdoors in a partially open year around greenhouse and have now started a monthly Sulfer spray regiment with this plant using Bonide Sulfer Fungicide. This product controls according to the label both mites and it a fungicide. Will see how it works.