Cold Hardy Citrus

[manfromyard]

eyeckr, where are you located ? manfromyard is probably from Atlanta or close by. The problem wasn't 2" of snow. The problem was bad icy conditions. Snow isn't too bad. Ice is bad. B'ham , Alabama got slammed too. Manfromyard could be somewhere between the Alabama line and Georgia. Tom

I live in Atlanta metro area. I work downtown and by the time I could leave, it was impossible to get home.
one apple and one bottle of water for 2 days was brutal.

Anyways. My parfianka is resprouting from the ground.  Thomasville is green at the base, but so much of the trunk is dead, that I don't think it can come back,  literally maybe 3 inches of green. I've never heard if citrus other than meyers that can come back like that. I'll try to hold back till the Southeast Citrus Expo before I dig it up and replace it. Might find another yuzuquat there since mine died as well.

[Millet]

Citrus trees, under certain circumstances, are more resistant to frost and freeze than under others.  Disease conditions,  undernourished trees, insects, the degree of dormancy, all bear an important relation to the amount of cold a tree can successfully withstand.  Diseased conditions reduce the resistant power of the tree as much as do attacks of insects.  Citrus trees are in much better condition to withstand cold when well supplied with food, so that they form healthy vigorous shoots and well develop leaves, than when trees are starved or only poorly fed. It has been shown, in many instances, that trees affected by white-fly, scale or mealybugs, suffer to a far greater degree in a cold period than those free from these pests. Unfortunately, the citrus tree is not distinctly periodic in its growth.  It responds readily to short periods of warm weather. The sap starts to flow, and the buds begin to swell. In this condition a citrus tree may be severely injured by a comparatively higher temperature. How many degrees more of cold a tree will stand when dormant than when not dormant cannot be definitely stated, but the difference is appreciable. - Millet

That there exists a mutual interrelation between the root stock and cion cannot be doubted.  In many cases a hardy stock has a market influence on the power of the cion to withstand cold without injury.  In order of frost resistance root stocks can be arranged as follows: trifoliate orange, sour orange, sweet orange, grapefruit, and rough lemon. Further it has repeatedly been observed that tree suffer more from cold if the preceding period had been dry.

[Millet]

What to do when a tree has been frozen.  In treating trees severely injured by cold, three courses are open to the grower: (1) Leave the tree alone, (2) cut the tree back to the soil, (3) Cut the tree back part way.  Everything considered, leaving the tree alone is the best plan.  For some time following frost/freeze injury it is impossible to determine how much pruning should be undertaken.  If cut back to the ground, more of the tops may be removed than necessary, and if headed back part way they may have to be pruned further at a later date.  There is no need for haste.  Nothing can save trees, or parts of trees, that have been frozen.  Much labor may be prevented by waiting until the exact extent of the injury can be determined.  This cannot be decided until growth starts.  Usually cold damage occurs in December, January and February, and sprouts do not arise from unjured branches  until spring growth begins.  If the injury is severe it may be much later.   When shoots have grown far enough to make it reasonably certain that branches will not die back farther, is soon enough to start the pruning. - Millet

[TriangleJohn]

eyeckr - Sorry it has taken me a while to respond. My Ichang Lemons were grafted, small and I believe they came from Georgia or South Carolina (they were part of a local arboretum's plant sale). I'm in Raleigh, NC zone 7b. Most winters are much milder and stuff rarely suffers, this year even the old established trees at the arboretum either died or froze back to the ground. I had two Changsha and two Ichang, all four were small enough to slip a bucket over on the really cold nights. They stayed green near the base until the weather switched to Spring, then they died.

I believe I have some plants that originally came from you. Years ago a neighbor of mine was traveling in your area and stopped by and picked up some seedlings. It would be sometime around 2007, 08, or 09, in the summer. She brought home some citrus, chocolate tree seedlings and strawberry guava seedlings. Out of that group the key lime is still alive and massive (in a pot in the greenhouse), the strawberry guava is also very large, in a pot, brought in for the winter - seedlings sometimes pop up in the garden, and then there is this one hardy citrus that is still alive and in the ground. Looks like a citrange. It had a hand written tag on it that seemed to say 'Dalton' but the writing had been smeared and was just barely readable. It has only bloomed one time and has never set fruit. Do you have any ideas what it could be? possibly one of your 'Dunstans'?

[eyeckr]

TriangleJohn Sorry about your Ichangs and Changshas. How low did you go? I lost my favorite Changsha which had consistently sweet and juicy fruit. The trunk is split terribly. I did make a small graft of it on a nearby trifoliate but it was still a very tiny scion that was not established and also died off this winter. I'm still hoping that I'll get a sprout come up from the base somewhere. I was impressed that my Ichangs made it. I was also very surprised how well my Ten Degree Tangerine, '2-2' variety held up in the cold. It was one of the last to show cold stress and first to bounce back with a vengeance this spring. It is easily now the largest citrus tree in my backyard.

Good to hear that your Key Lime is doing well. I'm wondering if it was a cutting or seedling that made its way to you? Either way I expect at this point it should be fruiting by now. Do you like the strawberry guava fruit? I like it and the Yellow Lemon Guava variety as well. I can't imagine the citrange you have being anything other than Dunstan especially if the tag looks close the spelling.

[TriangleJohn]

The Key Lime has lots of fruit almost year round. It appears to be a seedling (I can't see a graft line). It is so large I have to prune it multiple times each year just to keep it from touching the roof in the greenhouse. The big surprise out of that group of seedlings was one of the Theobromas. Most stayed small and slow growing but there was this one that got very big, very fast. It eventually got too big to move around and it died even though it was in the greenhouse because I keep the temps on the cool side for the citrus. I do like the Strawberry Guavas. They seem to taste better in the winter when I have them parked inside the greenhouse. This property (old house but new to me) came with a kid sized basketball court which is where I built a 20 by 30 hoophouse that I seal up tight in the winter and heat with an old wood burning stove. It has a 15 foot center ridge. The space is so large and the wood stove so good at keeping things above freezing that I switched from trying to grow citrus outdoors and now keep everybody in large pots inside. When they get to the point that they are touching the roof I will chip holes into the asphalt and plant them in the ground inside. My citrus collection is garden center bought and all the other tropical fruit trees are seed grown from the local Asian market or from other gardeners.

[manfromyard]

Just an update,

My yuzuquat and citrangequat both came back strong. They're winners!