I don't know but some people say the flying dragon fruit is edible. I didn't think much of the flying dragon fruit's flavor. 897 probably taste a lot better than FD. I didn't get a notice of your question or I would have responded much sooner.

Steve

I guess edible in that you wouldn't die from eating it. Having recently went through separating a box of FD fruit from their seeds, all I can think about is that citrusy kerosene smell haha...

I have a couple of recipes for rendering FD/poncirus fruits into marmalade that's supposedly pretty good though! I'd imagine it'd work well for the less edible varieties of citrus like poncirus hybrids etc

There are different degrees of "edibility". I haven't personally tried it but watching one video I got the impression poncirus hybrid US 897 definitely has an off-flavor but one man was able to manage to enjoy eating them like an orange. (Although I'm sure no one would eat them if there were normal oranges available as an alternative to eat)

Most poncirus hybrids are almost as bad as poncirus itself, but apparently there are a few that have much less of the poncirus taste.

Now when it comes to Yuzu, I haven't found it to be that bad. I would forage for them if they were growing in the wild and it was a survival situation. Their peels are also a bit more tender and less bitter than regular citrus, not like kumquat but maybe more like mandarinquat. So you can cook diced up Yuzu with the peels still on. (Like as a condiment to fish)

Some of these fruit are just inconvenient to eat because they are loaded with so many seeds.

I just discovered a citrus seedling (calamondin??) growing in one of my potted plants outside. It must have grown from a seed that fell in there by accident. It is showing some slight burning of leaves, but still alive. I’ll post a pic when I get a chance.

Update

Sour orange is drying out and presumed near dead

Replacement Seville is hardened off for new testing.

Old seville

I have replaced it with another and it just pass 23 hours 20F or lower down to 16F-15F-16F-15F-16F-15F-16F for 9 hours. The US897's and the C35 look undamaged.

All others have survived.

Steve

That’s great Steve. We’ll keep each other updated on our outdoor trees.

Fun experiments to keep you busy during winter. I am thinking I need a spot in my garden to do such things. I have a bunch of PT seeds and wondering if they will sprout in spring if I bury some now? I have a small protected area and I think I can still dig down a bit before the polar chill hits this weekend - predicted 0F for couple of nights.

Wait to plant in February mid to late if you plant outside. They will do better.

Steve

Keep them moist

In Feb ground will be frozen solid. I think I will put some in a pot and cover with mulch. In March and April I can plant a few more to see if it makes any difference.

I stored most of them in the fridge in a moist tissue paper with a bit of cinnamon to prevent fungus. I did, of course, plant 4-5 seeds in a pot about 2 weeks back and I think I see one little bump in the soil. In Feb I want to plant a few more seeds indoors to see if cold stratification improves germination.

Tonight is the big freeze. I have brought 1 US897 tree in at 15F, another in at 10F and will leave my last US897 though the night to face -8F in a protected micro zone. about 0.0F. Pulled my C35, Seville,and UE897 at 6f. One to remain over night

I'm glad to hear we are not the only ones with that cold. ;P Hope the trees are ok for ya!

You guys that are zone pushers should be a little nicer toward plant/tree,s that don,t belong out of their comfort zone, it,s like a tropical guy make him work in Alaska in oilfield s with no cloth.

I am much nicer and my tree,s trying their best with what I give them. “ Happiness “ For them and me.

Bob It isn't that bad. All my trees have held there leaves. I have 1 more US897 to bring in. It is the 0.0F test tree. All of these trees are so scarred up with failed graft attempts that they are useless.All of the trees have survived multiple 14F.. I will bring these trees into full growth to ascertain the damage if any.

Steve

Steve, are you using those hardy tree,s for rootstock or fruiting? My trees are not exposed to temps lower than 40*. They are in the workshop with temps around 65*, so I really don,t worry much . They are growing and blooming now and will be spraying them with GA 3 soon for polenation. Anyway good luck with your project, you are just a tryingness person, sure good to have on this forum.

These are strictly rootstock trees. The sour orange can make oranges but I am going to have to multiple graft the highest bud to the lowest trunk to make any use of it. The C35 will need the same treatment above. The US897 I have successfully rooted a cutting from the 50th bud node. While very difficult the tri-leaf citrus root with success.. The mono leaf citrus cuttings are unrootable. If my 0F US897 survives I will plant it's rooted cutting outside in hard pan clay.

Steve

When you have the best hardy rootstock, the variety that you graft on is still vulnerable to low temps, right?

My tree's have rootstock of several kinds, don't really know, because i did not tag them, because at the time i was not really familiar with citrus, did not know what to expect.

At the end i now have nice tree's i am happy with, just have to many.

Bob

Only poncirus trifoliata and Flying dragon can add up to 5F cold hardiness to your scion. Did you cut up your seed grown kumquat tree yet.

Steve

I do have a few Flying D. grafted but can 't tell which tree has them. Kumquat tree is now in the garage, ladies that want the tree were not ready with the tree at their home. I f they don't come and get it that tree will be totally converted to something of my liking, it better be a good one. I 'm really not a lime/lemon guy, 2 is enough.

You could try grafting a meiwa kumquat on it so you will have a mature Meiwa on its own roots.

Seville sour appears dead after low of 10F, while C35 and US897 appear to have survived 10F. A low of 0F appears to have damaged my US897 and I don' know if it has survived yet. At the least it will loose most if not all its leaves. All the trees survived 15F. I did not get to test out 5F because I didn't want to get up at 4 am. to bring another tree inside as the temps dropped to 0.0F

Steve

Photo

The leaves smell bad when crushed. I see little chance of survival.

Crispy leaves.

The leaves on all of the US897 and C 35 smell good when crush..

10F C35

0 degreeF US897

None of these trees ever came inside before The 13F low. They were brought inside once to warm the roots to 40F so they wouldn't freeze solid. for the final testing to 0.0 F.

and the winner is....

Anyone using 897 is the winner

The plant could still be alive even if it has lost its leaves.

So I have a question for you folks. Why is it important that the leaves be intact at such low temperatures? Broad leaf cold hardy plants usually shed their leaves below freezing. Do you expect the leaves to be intact and why is that important?

It isn't important except that when evergreen citrus lose leaves due to low temperature they die a few degees colder. Mountain Laural, rhododendron, holly hold onto leaves down below -25F.

Steve

It isn't important except that when evergreen citrus lose leaves due to low temperature they die a few degees colder. Mountain Laural, rhododendron, holly hold onto leaves down below -25F.

Steve

Thanks Steve. That is good enough explanation.

0-F US897 has ceased to loose leaf composure and its twig are green and pliable. 10 F Seville is drying on down its trunk. 10 F C35 looks sad but is still pliable. 10F US897 looks as if it was just brought in for the cold month with 0 leaf lose or curling.

Steve

i live in western washington, zone 8B, for next winter i want to try a Taitri, yuzu, FD and swingle. it usually doenst ever get colder than 19 degrees at the worst, my problem is the rain, I want to see what does the best so i can start grafting, any suggestions which would be the best based on the experts experience

Flying dragon as long as your soil is not calcareous. It adds 5F cold hardiness to the scion.

rootstock comparison chart

zero degree US897 has put on growth.

Steve

C35 looses leaves after 10F exposure.

0 degree F US897 has dropped what it will drop and is putting out new shoots that hold up well in several 22F cold nighs

All these trees will stay outside till spring unless temps drop below 10F for the growing tree.

Steve

All the US897 survived as well as the C35. All the Seville orange trees died at about 15F

You gotta send me some US897 seeds when you get some

I would like to try some of those too! I eventually want to grow so e tasty citrus in ground in wa state

"Steve, there is also a difference in size of those trees".

1 year later and a blast of cold down to 10F with a lot of high teens and low 20's. My 2 Seville sours (survived ?) on top of my roof though very rough cold being 1 year older when all were killed by 15F last year.

Left-unpruned. Right front-pruned.

No damage to my US897. Just like last year.

If my 2 sevilles survive they will work well with my Valentine pomelo future graft. The trunk will be hardier than my VP.

Steve

One Seville has survived maybe another.

New growth after 10F low.

Steve

It’s not going to give up, Steve :) very nice!

Air temperature is not the same as soil temp; and it is soil temp that determines if the root will survive, even if all the leaves get burned.

Since these trees will go in ground outside the roots will never get below freezing. The trunk is hardy enough that if the heating system fails and the tree dies it will not be because the roots were to tender.

Steve

One of the 2 sour oranges has died. There is no indications of root rot or that the roots ever dried out. The soil was kept moist but never wet or soggy.

Almost all the roots were dead on the tree with the small shoots. My conclusion is that the sour orange rootstock is a good choice for any citrus with a cold hardiness of 10F or warmer. The tree should be low grafted, back filled to above the graft line, and roots heavily mulched.

My potted US897 is still outside and undamaged with lows in the teens and one night to 10F.

Steve

Steve

Fukushu kumquat cutting placed outside in 24F temps spends 6 hours outside in dropping temperatures to be brought back inside at 18F temps. Did it survive? We'll see in time.

14 hours after bringing it inside

Steve

Fukushu's leaves turned grayish green. They were probably dead upon coming inside. The stem is still questionable.

Steve

Steve, what's showing the most promise? The only thing that seems cold hardy for root stock (at least for me) is my FD, which I've got one in ground that has gone into the low teens for long duration when fully dormant.

My PT are also the only things that really hold up over winter here. They have gone down to -12F and several -6F The US897s desiccate as springtime arrives and start dyeing back. I will have to bring my US897 in very soon so it can hydrate or it will die back. If the US897 were in ground it might do better. The US897 showed it could take a trunk temperature down to 0 F so If you had a greenhouse failure on an owari satsuma you tree should come out OK down to temperature lower than many other rootstocks would. The US897 produces better fruit than most other root stocks. While the seville sour trunk survived the roots were killed so it would not do well as a potted tree left out in that kind of cold.

Steve