The Tropical Fruit Forum

I recently purchased a tiny Hardy Fig tree from a nursery, along with a dozen or so berry shrubs.  Some of these had already broke dormancy and are starting to push out leaf growth.  However, we haven't reached the last frost date yet in my area, and it will likely dip into the high 20sF some nights over the next week or two.  These plants are all rated to -10F or worse, but that assumes they are fully dormant.   What should I do with them in their current state?  Are they likely to survive a frost unscathed?  Or will the new growth die off?   I haven't planted them yet, they are still in containers.  I could leave them in my garage until frost risk is over, or leave them outside in the sun and bring them in on freezing nights. 

Suggestions?

Btw these are goji, currants, gooseberries, elderberries, etc.

I want to start another round of rootstock trees.  Looking for somebody who will sell me around fifty seeds, or a few fruits with seeds inside.

I mentioned this in another thread but I've been pondering it for some time.  The idea started when I was considering ways to directly warm the root zone of container trees.  I'd read that optimal growth is acheived with warm roots, but warm canopies seem less critical.  I was thinking if you grew them hydroponically you could heat the water supply to keep the roots warm at all times while letting air temps to drop in the winter.  I know very little about hydroponics, though.  A quick search on hydroponic citrus only turns up drip irrigation systems called Open Hydroponic Systems.  This isn't what I'm talking about.  I can't find any information on fully-immersed growing of citrus.   I assume you'd need to aerate the water, add nutrients, and possibly anti-fungal/anti-microbials to avoid rot. 

Thoughts?

"The company plans to announce on Wednesday a three-year research agreement with the Citrus Research and Development Foundation, a nonprofit created by the Florida citrus industry. The partnership aims to develop new ways to combat citrus greening, an incurable bacterial disease that depletes trees and can cause fruit to drop to the ground prematurely."

article:  http://archive.is/TVOCq




# original source (requires WSJ login)
https://www.wsj.com/articles/bayer-joins-fight-against-citrus-greening-disease-1502884801

A bunch of old leaves one of my minneolas and an adjacent tree dropped at once, leaving their petiole stubs behind.  These trees seem quite healthy otherwise, and have large new growth flushes that are currently expanding.  I understand that old leaves normally drop entirely, and leaving the petiole stub indicates stress of some kind.  The temperature has made some drastic swings lately, but all the other trees are fine.  I'm wondering if perhaps they are too close to the propane backup heater.

Anybody have experience with these varieties?  Their reported unique flavor always sounded interesting to me but I don't have much use for juice so I'm not sure what I would do with the seedy fruit.  I looked online for the fresh fruit for delivery but can't find any.  There is bottled 100% juice available but not sure if its good representation of fresh. 

I'm running out of space right now but I still have the itch to try new varieties. 

I've accumulated pretty much every kumquat and hybrid that I can find.  Here's my impressions so far...

Nagami (Nordmann Seedless) - excellent taste.  Sometimes a slight soapy taste if not 100% ripe, somewhat astringent also
Nagami - excellent taste but has seeds.  More sour than nordmann because its fatter and so has more juice.  Sometimes a slight soapy taste if not 100% ripe,   somewhat astringent also
Marumi - excellent taste, some seeds
Meiwa - excellent taste, some seeds.  Less sour than other kumquats because it has more flesh than juice
Fukushu/Changshau - my personal favorite.  Initially mine were about the same size as marumi/meiwa and nearly seedless.  More recent crops have been much larger, about the size of a golf ball, and with significantly more seeds.  The smaller ones were better in my opinion.  I'm hoping that limiting pollination or using giberellic acid would help reduce seed count and also fruit size.
Hong Kong - not really edible because of tiny fruit size, no juice, all seeds.  I did eat a bit of the flesh on one and it is somewhat sweet but this is a pure oranamental & breeding parent
Indio Mandarinquat -  poor taste for two years in a row.  Skin is thin and dry, not enough sweetness to offset sour juice.  Off taste similar to Rangpur but less spicy.
Centennial Variegated - poor taste for me on my first crop.  Similar to Indio Mandarinquat.  Thin is skin and dry, not enough sweetness to offset sour juice.  Off taste similar to Rangpur but less spicy.    This variety supposedly has a reputation for good taste so I'm hoping it will improve next year but I don't expect the character to change.
Nippon Orangequat - decent but somewhat bland taste.  Skin is thick and bland, whole fruit is a bit sloppy as the flesh is soft and juicy.  Not worthwhile in my opinion because skin is not sweet like more common kumquats, size is as large as a navel orange, taste inferior to navel orange, and has seeds.  You'd be better off with another kumquat or a sweet orange.
"Excalibur" Red Lime - UCR mentions likely Kumquat/Rangpur hybrid.  This one was a surprise to me.   I couldn't locate one forever and ended up trading with Lorewren on this forum who lives nearby to me.  I've been eating the first crop over the past four months and they keep getting better the longer they hang on the tree.  They are now dark orange and about the size of a Clementine.  They taste quite good, like what I was expecting from Nippon Orangequat.  The skin is sweet and relatively thick.  When first turning orange 3mo ago they were sour but now they are sweeter and I eat them out of hand.  There is a bit of the Rangpur taste but not strong.  Seedy, though.

Lakeland Limequat - typical lime flavor.  Thin rind that was rather dry and not at all sweet.  Few seeds.   I wouldn't recommend over a Bearss lime unless you need the cold hardiness. 
Sunquat -  bright yellow like a meyer lemon, and tasted similar.  Thin skin, not sweet but not too dry.  Much sweeter than a true lemon.  Again, if you need a lemon I'd stick with a real one, but the Sunquat fruit is very attractive looking as it's perfectly round and bright yellow.   I'm thinking I will keep this as an ornamental.    (RyanL - you called it)

Archive.org has a few copies of the old forum over the years, but many of the newer ones just show the "too many connections" error for most pages and are useless.  This one from February 2015 seems solid, though:

https://web.archive.org/web/20150328005144/http://citrus.forumup.org/

I was away for a week or so and when I came back I noticed some of my trees getting mottled yellow areas.  Some leaves had just yellow dots, others were more advanced.   Seems to affect both old and very new growth pretty randomly.

I think this is a mandarin:



kumquats:



I haven't ever done a soil PH test on my potted trees.   They are in ~5:5:1 peat:mulch:perlite mix which I was assuming would keep PH in check as I have relatively alkaline water.  I recently doubled (if not more) the amount of Osmocote Plus on all trees and I've been adding a small amount of Jack's HPF when spraying soap to combat scale every week or two.  I can't imagine the trees aren't receiving enough zinc so I wonder if soil PH is the issue, or I'm mistaken thinking this is zinc deficiency.

I think I have a soil PH test kit somewhere and if not I can get some of those pool strips.  I have garden sulphur around somewhere but I was already worried about root burn when using it on potted plants.

a Moro Blood Orange story...

2013: Bought it at home depot, and after this picture I repotted it into a rootmaker container that Millet gave me.  Soil is 5:5:1 mix of cedar mulch/peat/perlite


2014: Looking fantastic.  Huge root and canopy growth, nice dark green all around.  After taking this picture I cleaned the soil off the roots and repotted it into a slightly larger diameter rootmaker container.  The tree was nearly 6ft tall including container.


2015: Looks about the same as last year, no significant new growth.  Some of the oldest leaves are getting very yellow and overall color less green than last year.  Somethere around this time I had stopped using liquid fertilizer and switched to only Osmocote Plus because with so many trees it was a huge burden to mix many gallons of fertilizer-water.  Right before taking this picture I had repotted it into a 4" wider rootmaker pot, which has a diameter of 19", however, I did not clean the old soil off I just filled in around it.  Over the winter those yellow areas all dropped their leaves and the same twigs died back.  The newer growth stuck around.  It bloomed but none of the fruit held.


2016: Here it is today during repotting.  The canopy is smaller than it was 2 years ago, though the rootball is as large as ever and filled a 19" diameter rootmaker container.  You can't see in the picture but it does have new white root tips around the perimeter.  It had put out substantial new growth in spring but it still is overall smaller than its peak.  It looks much lighter green than it once did.   I regularly refresh the Osmocote and when repotting I still saw plenty of unspent pellets floating around.  This time when I repotted I cleaned all the old soil out extensively.  I planted it in the same 19" wide container but this time I planted it "higher" as after cleaning it had some roots hanging down that looked like they could begin to fill the lower third of the container.  I've seen 15ft tall trees in containers this size so I'm skeptical that it really needs a wider one.


So, I'm disappointed that it isn't thriving.  I'm not yet worried at this point because the roots look great.  When I repotted today the soil was mostly mud as the cedar chips had almost completely decomposed.  I think not cleaning the old soil off last year was a big mistake.  However, I thought that if soil aeration was limiting growth it would show up as rotted roots of which I found none.  So, I'm stumped as to what the problem is here.... insufficient fertilizer or insufficient aeration?  Other possibility is insufficient light, as the nearby apple trees at my old place were starting to grow in and shade it.  At my new place all my trees get direct sunlight the entire day.

My new greenhouse won't be ready until next year at least so all trees have to stay in containers until then, and I can't switch to sand/gritty mix because it is too heavy to carry.

I was recently in Kauai island on Hawaii and visited an awesome tropical fruit & nursery.  Unfortunately none of the tropical fruit trees were approved for export to the mainland.  They had a lot of nice looking citrus trees but I overheard an employee telling a prospective (local) customer that they couldn't sell any citrus trees because they were infected with a disease "that causes them to reach a certain size and then die".  I didn't get a chance to ask about it but it sounds like HLB has made it to Hawaii.

I was at Longwood Gardens in PA last weekend and noticed a 12ft tall Trifoliate Orange tree.  I didn't realize they would survive outdoors in zone6.  Wikipedia does mention that they are hardy in this zone but I misremembered thinking even the most hard citrus wouldn't survive here.  Knowing that they will, I'm thinking of planting Flying Dragon rootstock seedlings right in the ground instead of carting them into my greenhouse in winter.  I'll have to get some more FD seeds and try it out.



I also included some pictures of other large citrus that were in containers indoors at the same place.  A Nagami Kumquat and Oroblanco Grapefruit hybrid.