My friend got a Meiwa kumquat for is inner city Atlanta GA micro climate yard. It died at a low of 26 F because it was grafted to a lemon rootstock. Had his tree been grafted to Flying dragon he would now have a nice productive tree in th 4 ft to 6 ft range. Rootstock also dictated cold hardiness and should be on the label.

6b Steve.

There are so many factors that determine cold hardiness, including humidity, soil moisture, air drainage, duration of the cold, the health of the plant itself, and many others. It is always best to protect your plants whenever the temperature is at or below freezing.

I'm jealous of johnmerr's tropical climate! I never have liked cold weather anyway and now I have citrus trees to cover and stress over so it's even worse! I have heard it said that local nurseries sell trees appropriate for the local area...ok, so the sales people are good at what they do....but they are selling avocado plants and Key limes here and they will freeze to death most winters if not brought in. If you plant in-ground, there comes a time when the tree just has to make it on its own due to how many trees you have, how big the tree has become, or because you just get tired of covering and uncovering trees. It would be so much easier if those really cold nights didn't also have a strong north wind whipping at the coverings. I actually fired up a BBQ pit one cold winter night, closed the lid, and put it out with my large trees. The trees closest to the warmth of the pit lost a few leaves that were too close to the heat but did fine otherwise. The trees beyond the warmth of the pit didn't loose leaves due being too close to the pit and they also did fine otherwise....well, all of the trees lost some leaves because of the dry cold but I couldn't tell that the BBQ pit helped a bit. Water spray would have been better but in the end I didn't loose my trees. Several years back...maybe five years back now....we got down into the teens and I lost some trees that were covered. Those are the years we need the labels to tell us about.....maybe someone will create a freeze-hardiness model so we can enter the species, the root stock, the trunk diameter, humidity, days of dormancy, average temperatures in the previous two months, soil temperature, etc., etc....and it will spit out how low and for how long the tree is expected to withstand.

Water, as in sprinklers or misters always offers the best protection; first is the temperature of the water and second is the heat it gives off when it freezes. A model would be good; but I don't think many people do field trials to determine survivability (maybe unplanned trials). Maybe they know they lost all their trees when it got to 25; but that doesn't mean they might not have survived at 26. What I am trying to say here is it is really not an exact science; but rather anecdotal evidence; i.e. under different circumstances my trees might well have survived at 25.

John,

I abhor cold; it is one of the reasons I live in Guatemala. I am trained in jungle survival, mountain survival, and desert survival; I declined arctic survival; because I was afraid I would not survive! I live in Guatemala City and Antigua, Guatemala, both of which are known as "City of Eternal Springtime"... houses have no heating or air conditioning; but sometimes it gets too cold for me and I have to go to my farm on the South coast, where it is ALWAYS warm.... some would say HOT.

John, I get your frustration with the hardiness zones and labels. You mentioned stores selling trees for their region. Our local HD garden center sells apple and peach trees, with labels saying they need some cold. Poor unsuspecting customers buy them here!

John M., you remind me of my husband, lol. He is from NYC and every year, I make a couple of comments along the lines of missing the fall leaves and seeing Christmas in NY. His response is always "Nope!," no matter what I say. He's like you in that when we get a "cold front," he's actually cold and the guy with socks under his flip-flops. I know this is randomly off topic, but I wanted to chat since you mentioned it. I love hearing your stories. Of the ones you mention, I am trained only in jungle survival; there were only two women in my class. One of our guys was a public affairs officer, so we were able to get a few pics throughout the course.. I am so lucky to have those to share with my kids. My son (10 yrs) found my bolo knife (in a storage box) when he was 8 and begged for it for almost two years. I had it dulled and gave it to him for his 10th bday. Here's a pic of our dinner one night. Tasted like chicken.

John you are so right! I would worry about them just as much as you do unless I live in a climate that is nothing short of tropical or South California, on the west side of all these Arctic Fronts..Why, even Oregon and Washington have less cold than you do..Let us know how any of your trees planted in the ground do this winter and share your winter protection set ups..I would love to follow your progress..

figs,

I would love that dinner... way better than chicken... somewhere between a pork chop and a lobster. As to cold, I don't think, after a million years of evolution it is an accident that my body temperature is 98.6F.

Johnmerr. I think that as far as body temperature goes we run colder than most warm blooded animals by up to 5 F.

If I didn't have ties here in the states, I would seriously consider applying for a job on John M.'s farms.....or go see if figg's son needs help chasing giant lizards in Hawaii.

John, darn it, I should have called dibs on being a helper on John M's farm! The lizard was in the Philippines (our training was there).. our Dept of Ag would FREAK out if that giant lizard was caught here (although we have millions of little ones). Every time an animal is caught that isn't supposed to be here it makes the news for a couple days straight, lol. AND an investigation. Where in TX are you?

figs, I'm in SE Texas....Beaumont area...I'm in 9a

Speaking of freeze hardiness, we just got our first frost Sunday AM and Monday (today) AM. They were light frosts but they counted. Now the weather is supposed to stay between the 50's at night and 70's in the days for a week or so. I didn't cover anything for the frosts since my trees need to know winter is coming but this kind of thing happens deeper in the winter. It's a crazy looking yard at night with blue tarps over my smaller trees and then I have to uncover them in the mornings so they won't get too hot. I'm thankful for the warm days and I don't think I could haul all of my plants indoors all winter like some of you do...hats off to you for loving citrus that much.....but that's the one thing that makes outdoor trees in a borderline region difficult. I'll try to post some photos here of coverups as someone requested earlier. I guess we all have our favorite methods. I have experimented and tried different things according to what I had on hand and how big my trees were. Blue tarps seem to be my fallback since I use them for other purposes too.

John, wow, Beaumont area, very SE close to LA, nice! I remember my mom using blankets and tarps on those rare nights when she thought the trees might not make it. She lives in San Antonio, so warm enough throughout most winter nights, but not always.

list of most cold hardy citrus

6b Steve

Hey Steve, thanks for that list.