These survived -10 F

[Vlad]

Last winter, we had a day when it got down to -10 F and these two in ground trees survived without any damage and with no protection.
The pic below is a 5 ft tall flying dragon:



I took a sucker of a trifoliate rootstock (do not know what it is) and rooted it years ago. It is now at least 6 ft tall and this what it looks like now:

[poncirsguy]

Poncirus trifoliata and Flying dragon can both go down to -25F and survive.

[Ilya11]

Poncirus trifoliata and Flying dragon can both go down to -25F and survive.

No way, even -25C (-13F) is at the limit of its resistance.

[poncirsguy]

My potted PT went down to -12F with no problems and it was out in the open.   it can go a good bit colder.

[Ilya11]

With sufficient protection you can probably cultivate mango at your place.

[bussone]

Poncirus trifoliata and Flying dragon can both go down to -25F and survive.

No way, even -25C (-13F) is at the limit of its resistance.

You are severely pushing your luck and you probably need a friendly microclimate, but there's a poncirus documented in SE Michigan in a town that has gotten to -18 to -22F in recent years.

But if it's living in an eastern US zone 6, -10F to -20F is not out of the question. Never lasts long, but it happens occasionally.

[kumin]

I find late season growth quite vulnerable. Spring growth has a chance to lignify better and survives much better.