The Tropical Fruit Forum

My swamp lemon trees finally produced fruit this year after making the largest orange blossoms I’ve ever seen on any citrus. I noticed that the swamp lemons have a more pronounced petal outline at stem than the Poncirus or flying dragon and the pulp is lighter color, almost whiter, and definitely doesn’t have as bitter turpentine-like taste as the flying dragon/ Poncirus. The first pic with the denser clusters of blooms is the regular Poncirus and the larger blooms are swamp lemon. Neither have fragrance that I can detect but my sense of smell is weak.

I’m trying to post pics of my Prague that I planted in ground this spring and a few that I grafted this spring on Trifoliata. Weird citrus. It made a few tiny flowers that didn’t make fruit this year while it was still in pot. Got it from McKenzie Farms several years ago grafted on trifoliata.

I haven’t been on here in a long time, but I remember posting a question about grafting FD to PT. I did it, and it looks pretty good. The rootstock hasn’t overgrown the scion over the past several years, so I guess it’s ok.

I’ve tried putting wire cage around trees and fill it with leaves from yard. I get to low single digits and sometimes zero or below rarely. It didn’t matter; they died to the ground. The only way I can prevent severe damage is sturdy wood cold frame or pvc pipe dome cover in 4 mil plastic sheeting to the ground with edges weighted down with rocks, water barrels inside, and small 250 watt space heater inside on a thermo cube to turn it on and off. Does not matter if it’s a satsuma or citrange, if no space heater, it dies or so severely damaged it may as well be gone. Last year, I went to two degrees F with 60 mph winds and no power for two hours, and lost 10 year old Rio red and about 10 other trees, but Kimbrough and Owari only partially damaged and a citradia next to house with plastic over pvc frame and 32 gallon water barrel was undamaged. Citradia trees in my orchard with plastic only or unprotected died completely. I bought small kerosene heaters as a back up for when power goes out and I can’t get generator started for this winter.

I’m so discouraged after the hard December freeze, I am close to quitting citrus altogether. I lost or suffered severe damage to everything except poncirus. My power was out for two hours during a 2 degree freeze with a high of 8 degrees and below freezing for about five days. That means my heaters were off in cold frames and we couldn’t get generator to start to get heaters back on. Then, I figured out I had used too long of an extension cord to supply power to my heaters in the valley orchard, so basically those citrus got no power or heat all winter until after the week of hard freeze, so they’re all dead except the side of the yuzu that was literally touching the side of the big water barrel.

Total losses:
Rio Red grapefruit ( heaters too small)
Seville
Bergamot ( too damaged to keep but alive)
Shiranui ( valley- no power)
Sugar Belle ( valley-no power)
Ichang lemon ( valley-no power)
Citradia air layer ( covered only, no barrel)
Citradia on poncirus air layer unprotected
Citrumelo 80-5 unprotected
Thomasville unprotected
Dunstan unprotected
Benton unprotected

Alive but severely damaged by house and got power back after two hours without it:
Owari
Kimbrough

Minimal leaf loss or tips of leaves damaged with power off two hours:
Seedless Changsha on flying dragon
Meiwa kumquat ( gets heat from French drain on south side of house)
Croxton grapefruit ( French drain south side of the house)
Saint Anne ( has two large barrels up against west side of tree)

My best survivors that didn’t have ground heat from French drain and only water barrels in a cold frame when heaters went out are Saint Anne and Changsha. My potted grafted-on-poncirus citrumelos and citradia trees were also undamaged.

My in ground shiranui lost 70% of its height last winter when we went to 14 degrees one night in March and I think my heaters l’un cold frames didn’t come on. It came back to three feet high this year but again, I went to 8 degrees for two hours with no electricity so no heaters, then next day 2 degrees and below freezing temps for almost a week while I was on vacation in Fl for a week. The shiranui looks bad again but trunk still green above graft line. The fruit doesn’t ripen until January commercially. I have one in a pot that I brought inside my house during the single- digit nightmare week, and it has one large green fruit on it now. Stuff ripens late for me here.

I washed and planted the seeds today. They actually look as good as any others I have planted in the past. Thanks, guys.

All the fruit on my Seville froze in December. Is it possible that the seeds inside the ruined fruit could be viable ?  The fruit was not fully ripe, still green when frozen to death.

Thanks for the response, Galatians. I’ll look that one up.

Yes, the 2 degrees F was outside temperature. I have used a digital thermometer about 6 years ago and noticed that the Rio Red got down to 19 degrees inside tent with heater on when it was zero degrees outside. The tree survived with minimal leaf damage. During that polar vortex, the outside temperature dropped a degree every minute as soon as sun went down, and dropped a degree every few seconds inside tent when heater turned off. This proved to me that I have to have heaters and cover citrus to keep them alive here.

I was having lows in single digits two days in a row with a known low of 2 degrees F, and not above freezing day and night from Friday through sometime the following Tuesday last week. I also lost power for two hours and couldn’t get generator started Friday morning as temperatures plunged to 8 degrees with a high that day of 11 degrees. All of my store-quality citrus have massive leaf damage but no trunk splits noted yet. Most of my Citradia trees, Dunstan, 80-5, Thomasville, Benton citrange that are unprotected only showing mild to moderate leaf damage. One large citradia on east side of an unheated cold frame with yuzu in it actually looks unscathed for now. The yuzu in unheated frame looks remarkably good with some leaf damage only.

I had to cut back on my use of space heaters due to inadequate amount of electricity to support my 15 outdoor trees in cold frames covered in 4 mil plastic sheeting. Each frame has potted citrus seedlings and grafted trees also. The poncirus hybrids even the newly grafted potted ones are unscathed.

My winners for this event so far with only one 250 watt space heater inside each enclosure are:
Saint Anne Satsuma ; only a few burnt leaves.

Seedless Changsha on flying dragon; few burnt leaves only.

Meiwa kumquat ; no leaf damage but lost all fruit.

Trees with moderate leaf damage in frames:
Croxton
Owari
Kimbrough
Seville sour orange : all fruit lost
Bergamot
Yuzu: unheated frame w 50 gallon water barrel

Trees with severe leaf loss:
Rio Red grapefruit : fruit lost
Changsha : unprotected
Shiranui
Sugar Belle
Ichang lemon

All frames have at least one water barrel and all at least one 250 watt space heater w larger frames having two heaters and two or three barrels.
I’m having another electric outlet installed outside by electrician next Monday.

Is poncirus rare or difficult to grow there?