Hi everyone,

Great board. Lots of good info.

I was wondering what is the hardiest citrus plant? Are there any that could survive a zone 6/7 winter with or without protection?

Regards,
Jay

The hardiest true citrus is a Trifoliate Orange. Easily withstanding temperatures less than 0F. According to Tom McClendon's book "Hardy Citrus For The Southeast" it can thrive as far north as Massachusetts, and also hardy inland at Saint Louis, Missouri. Fruit does not taste good. - Millet

Great, thanks for the info.

Well heck almighty. They should or probably do, grow them trifoliates up in southern coastal Alaska. Those boys are seeing zone 7 winters there and some fine summers too.

As trifoliata fruits are inedible you may as well go for the ornamental value and get a Flying Dragon trifoliate.

Or you could build an inpenetrable thorny hedge.

.....Alan.

What would be considered the hardiest citrus that tastes good. I only have meyer lemon trees and they have survived three winters outside but I would like to try other types.
I find the fruit on a meyer lemon to taste fine.

Not the hardiest but definitely a lot cold hardier than the Meyer lemons but tastes way better than Meyer lemons are the Satsuma mandarins, especially Owari Satsuma.

The first consideration is the selection of the
proper variety. Kumquats and satsuma are the most
cold-hardy, edible forms of citrus available and both
will normally survive in the warmer parts of the north.
Moreover, trifoliate orange is the most cold-hardy of
all citrus and an excellent rootstock for the others, as
it will convey its hardiness to the scion variety
budded on it. Thus, kumquat and satsuma budded on
trifoliate orange rootstock are the hardiest - Millet

Thanks for the info.
You will have to excuse my ignorance but can you buy satsuma or a kumquat with trifoliate orange rootstock? If not how do I get one or create one?
I do see every once and awhile a kumquat in the garden stores, would these be on trifoliate orange rootstock?

Most of my grafted citrus is on Trifoliata rootstock, most bought from Fl & Tx. It's most likely that where you are, it's on Tri. but ask the nursery. Sometimes it is labeled on tree as what kind of rootstock.

Actually the Changsha mandarin is a bit more hardy than the satsuma. The Changsha is loaded with seeds though, but is sweet. From what Stan has told me they are working on a seedless Changsha at the UGA.

Satsuma would be next in line & is one of my favorite citrus.

I happen to like both the looks and taste (as diluted juice anyway) of what is probably Morton citrage, whch is reportedly good to 5 degrees F and has big orange-like fruit. Grow it ungrafted on its own roots and even if you lose it once a decade or so, have it grow quickly back (especially if you protect the trunk base a little).