Trifoliate Orange in Zone6

[brian]

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.

[Radoslav]

Planting Flying Dragon is definitely a good idea, it is very ornamental tree, but sometimes it is tricky in zone 6.
I know many trifoliates doing great in this zone for many years, but I also know about many failed attempts. Microclimate and age of seedling can play a role.
It is important, how long and tough the winter in area really is.
I know that doyen of citrus growing in Czechoslovakia Mr. Urban talked about selections he made of poncirus from former Soviet Union to be able withstand winter in his area and other areas, especially with higher sea level, it means longer winters.

[brian]

Would I be better off starting seedlings in trays and then transplanting, or sowing directly into the ground?  I started some FD seedlings a few years ago in trays and they are extremely slow to grow, while grafted 1-3yr trees I've purchased are pretty vigorous. 

[Radoslav]

Young seedlings are more sensitive, so planting older plant with some protection in first years is better way, on other hand sowing the seeds can lead to natural selection to  strongest seedlings.
Personally, I recommend to use/combine both ways, older plants and seeds too.

[brian]

Good idea... I'll have a mix of both.

[Claytonnj]

I was at Longwood last year and happened across one of the oranges under a pine tree on the level below. I rounded the corner and up the steps to find the tree and what it was - they should move the identifying tag out from under the tree so people could read it, OUCH! LOL Anyway, I planted all the 23 seeds in that tiny orange golf ball in my raised garden bed when I got home and almost all of them came up this year! Does anyone know how many years before they fruit? On average, they grew about 6" in first year. I did place an old storm window atop bricks to protect them a bit over the winter. Looking forward to having a steady supply of citrus for friends and family cocktails!

[Citradia]

Google earth says I'm 6b, and my trifoliates and flying dragons have been outside unprotected on top of a mountain getting high northwest winds in winter since they were a foot tall, and are completely infased by winter. The only time I lost any was when I left some flying dragon seedlings about 6 inches tall in pots outside over winter when we had the polar vortex zero degrees all night long and hardly got above freezing all January long. Previous years, the potted trifoliata seedlings we're unscathed. Last year my trifoliata didn't drop all leaves. My large trifoliata has 3 small fruit on it this year but they are still green, whereas the larger tree in a neighbors yard down in the valley has larger fruit that is already yellow. Growing season length and annual heat units might play a part in fruit development in cooler climates.

[brian]

I really want to take advantage of this new knowledge somehow, but I can't come up with anything.  I can't eat trifoliate fruit and I now have enough seedlings from earlier this year for grafting stock.  I don't really need a hedgerow.  Maybe I'll plant one as a landscape tree.

[Citradia]

Landscape tree sounds good. I've read about some people making marmalade out of trifoliata, but that would take a lot of fruit and work for questionable results.

[countryboy1981]

I would only suggest trying trifoliate if you like a nasty resin on everything the juice touches.