I'm sure you've checked out the McKenzie Farms website. This is really the best place for info and purchasing, and is not too far away from you in SC. If I were in that part of the country, I would already be trialing some cold hardy citrus, even if I still lived in a zone 6!

What's most impressive is that this guy grows the citrus commercially, so he's knowledgeable in everything from variety selection to cold weather protection. Yeah, he's in a warmer area than you, but from what I hear he is totally willing to take the time to coach you through the whole process.

You'll get nothing edible without a lot of protection. Check out my website for some ideas

Here is a link that might be useful: mrtexas

Tex, are you saying there are things I might be able to grow with less protection that you don't think are worth growing? Even if I just had something really sour that I could use for cooking or to squeeze a little juice over some fish or something like that, that would be something I'd be very glad to have.
Fabaceae, I am familiar with McKenzie's site. That's where I first discovered there were even options to consider. I did e-mail him maybe a week ago but haven't heard back from him yet. He may not really do e-mail. I'm going to call him sooner or later, but I know he's got a business to run, and I only have one or two good protected locations for trees, so I want to find out as much as I can before I take my final round of questions to him.

Cousinfloyd - I will probably drive down to McKenzie's sometime this year and haul back some sizeable bushes. It all depends on how my in-ground citrus handle this winter. I can pick up anything you want on that trip.

I'm thinking of just planting Satsumas in the orchard and then building temporary shelters over them for the winter - probably covered with that fancy bubblewrap like pool covering stuff and maybe a heating cable. I will have room to keep quite a few citrus in pots to be used as backup for scion stock if I need to graft again should we have a really bad winter. I am also zone 7b but on the warm side.

John, thanks very much for that offer! I'll e-mail you about details.
You're right that I'm on the cold side of 7b, not 7a, at least according to the recent update, but I'm in a low-lying area that collects cold winter air, so I'm still not comfortable thinking of myself in 7b terms. I saw 3 degrees on the thermometer last year, but that was definitely colder than the average winter.
In any case, my first interest is in citrus hardy enough to take those kind of temperatures without things like heating cables. My best location is directly in front of my house, so for aesthetic reasons I don't really want to have a big plastic cover over the tree all winter either. I'd prefer to just cover the tree on the really cold nights (together with some water barrels). Any thoughts on whether the trees I listed above (owari satsumas, ichang lemons, yuzus, and citrangequats) would need any more than that level of protection?

All I've ever heard for this area (Raleigh) is that Changsha, citrange, satsumas and ichangs have survived the winter and produced a decent crop of fruit but that you can't expect a good crop every year or even every other year.

what I have witnessed in other peoples yards is that the trees do best when planted right up against the house on the south or southeast side and sheltered from winter wind. If they aren't early fruiting varieties then you risk losing the crop to hard freezes (which is why I am focused on satsumas which ripen in November for me). Changsha and citrange don't have the best flavor, or so I've been told - mine are just now fruiting size.

A friend that travels to Italy every year was telling me about how most of the lemon orchards over there are container grown and that they protect the trees from hard freezes. So, I guess a person could develop a very productive orchard with potted plants.

I don't consider any hybrid of trifoliate orange to be edible.

The USDA zones are based on the average lowest temperature.
Citrus trees die from the lowest temperature and/or length of freeze, not the average. Say goodbye to any edible citrus at 10-15F for a few hours unless you are willing to protect them by covering or heating.

Here is a link that might be useful: mrtexas

Changsha is not worth growing IMHO. A mouth full of seeds in every bite and IMHO it is not more cold hardy than satsuma. Citranges taste horrible. Ichang lemons are sour like vinegar without much lemon flavor.

Eric,
You "may" have luck with a citrumelo especially if you could find the 'dunstan' variety. This variety has survived below zero temps and fruited the following year in Mt Olive, NC. I think Dr AJ Bullard owns the tree. Also I have seen a large fruiting citrumelo in Salisbury, NC that has been there many years, this tree must have seen near zero (likely below) temps. There is a guy in Rock Hill, SC that sells seedlings from this tree if you google Chilly Palms nursery you can pull his site up. Gary Hollar in New Bern, NC may have 'dunstan' plants to sell. If you google Gary's nursery you should be able to see his site.

Very intriguing... Any idea what Dunstan Citrumelo can be used for? Is it good enough for eating of hand like a grapefruit, or just for flavoring, drinks, etc? More importantly, I wonder if it can it be harvested for any use at all (maybe as a lime substitute) by October in areas with a short growing season. As you can guess, I've not totally given up hope of growing citrus in the ground (with protection) here in zone 6b!

I have had satsumas take it down to close to 15 without any protection. They have taken an ice storm and an extremely rare snow (we get one about every 20 or so years on average) again without protection. They were not even fazed by the weather. I read that they won't take the weather, but I reckon my trees ain't reading the same articles that I am. The fruit is better than anything available in our stores in my part of Georgia. I have a moro blood orange that I planted last year that handled a night right at 20 this year without protection (the wind blew the cover off sometime during the night). It is putting on an enormous ammount of growth and starting to bloom right now, heck it was experiencing a growth spurt when it dropped to around 20 a couple of weeks ago, the cover stayed on that night, and it did not set back the new growth at all. The temperatures were measured by me in the part of the yard where the trees are and not off the news. With that being said, I live on a lake and the part of the yard (the south side) that faces the lake never gets frost, even when down into the upper teens. If you are willing to experiment I am sure you will find something that will make it with a little help from you. If I had listened to all the nay sayers I would have only apples, peaches, plums and figs, but being the hard headed individual that I am I now have citrus and avocados that I grow in my yard (even had papayas that I plant as annuals produce fruit). good luck.

'Dunstan' citrumelo is supposed to be the best "edible" hybrid with Poncirus from what I have read. A friend from GA that is very knowledgable about Citrus claims that 'dunstan' is quite good eaten as a grapefruit if sprinkled with sugar. I have tried the fruits from the above mentioned Salisbury, NC citrumelo and to me they make an excellent lemon substitute. The tree in Salisbury may be 'dunstan', the owner does not know. I did not try eating the fruits with sugar as a grapefruit. I made lemon ade that was very good and the owner of the tree told me that they make very good pies.

Thanks shane, Dunstan sounds pretty promising. Looks like Salisbury is a solid 7b, so I've got a one zone jump to make by siting in a warm microclimate and providing winter protection.

I'm thinking I can easily provide for the growth of these hardy in-ground citrus, but I'm not sure about the flowering and fruiting. With the kind of protection I would provide, I would be lucky to extend the frost free period more than 200 days. Anyone out there know if this is enough for any citrus?

I've seen what I think is "Dunstan Grapefruit" plants sold as "NC Grapefruit." Mine hasn't fruited yet so I don't know what it is good for. It is about 9-10 feet tall and in the ground. Maybe this year.

Stan McK is usually very good at responding to email. Perhaps there was a glitch.

One hybrid with trifoliate in it that is quite acceptable is Thomasville citrangequat. You eat it more as a kumquat. Another that has more trifoliate genes in it, that looks like a orange as fruit and is acceptable as a lemon substitute when well ripened (say, on fish or mixed with ginger ale), and is very cold hardy is "Rusk" citrange. It is also almost seedless.

I also meant to mention earlier that there is a 'dunstan' growing in MD and has been there for quite a few years. If you google dunstan grapefruit or citrumelo and MD you will likely find a newspaper article telling about this tree.

I checked out the article on the MD dunstan citrumelo, very interesting. I could not help noticing that it is growing in a zone 7b, the same as Salisbury NC, I was hoping it was a colder zone than that to give me some more hope...

The real turn-off though is that it took 15 years to fruit! In my online research of Dunstan I found another source that said the variety takes 14 years to fruit. I certainly don't have that much patience, especially if I'm going to be babying the thing. My experience of conventional citrus is that the plants grow quickly and fruit very young. I imagine most hardy citrus are the same -- but apparently not Dunstan?

Rusk and Morton citrange are two more hardy citrus hybrids touted as "approaching edibility" fresh, and great for juice, marmalade, etc... They are supposedly prolific bearers of early-maturing fruit, so I think my focus is beginning to shift, despite the enticing remarks I've encountered all over the internet regarding Dunstan's edibility.

p.s. Don's Hardy Citrus page is back up as of December, and he has a huge, extremely hardy citrumelo that has survived -5, but apparently produces awful tasting fruit. I'm guessing that it's something other than Dunstan!

Seed grown citrus can take 15+ years to fruit. They tend to get locked into a juvenile phase. Some are worse than others. Most potted plants are grafted which speeds things up.

The varieties of cold hardy citrus changes every year with new and improved cultivars coming on the scene. I wouldn't give up yet.

The citrange I got had a hand written tag that was hard to read. It looked like 'Dalton'. So far it is handling this winter outside just fine - our lowest temp so far has been 17.

As has been said Citrus grown from seed can take many years to bare fruit but if you could get one grafted onto Poncirus it not only will fruit sooner but should also be even more cold hardy. I have eaten 'rusk' citrange and it is quite good though it has a slight bitter taste. It is extremely juicy and very attractive. It is not quite as cold hardy as 'dunstan' sustaining damage in my area every winter. Personally I would think of 'rusk' as being a 7b citrus and 'dunstan' at least 7a. I suppose they could grow in colder zones depending on how much protection you are willing to provide. Ripening may be an issue in colder zones.

Yeah, I guess I've heard that about seedling citrus, and other fruiting plants before, but the MD citrumelo WAS grafted onto poncirus.

I'm also assuming that many of the named hardy citrus plants available that are not grafted are grown from cuttings? Shouldn't these bear sooner than those from seed?

Definitely believe you about citrumelo's greater hardiness, after seeing the pics of Don's big old tree in OK.

I am not certain what variety citrumelo Don has in OK but I can tell you it is not 'dunstan' because of the shape of the fruits. My guess is he has one called 'swingle'. As I recall 'dunstan' has mostly rounded fruits much like a true grapefruit. I am no botanist but many citrus (not all) will come back true to the parent and it is my understanding the poncirus hybrids will come back true. I am getting this info from the book CITRUS FOR THE SOUTHEAST by Tom McClendon. I think you can still get this book through the southeastern palm society website if you are interested.

"It looked like 'Dalton'"

"Benton" citrange maybe?

I am having good luck with Owari Satsuma. I have two of these mandarins planted in my front yard here in the Georgia mountains.

I do protect them in the winter with a wood/plastic sheet structure, but I think I may be overdoing it as there has never been a single leaf damaged by frost or freezes in the last three years that I have had these. The last few years the outside temps got down to 11F at the lowest.
The Owari Satsuma fruit has got to be one of the best citrus I have ever eaten. Period.

I also have a Thomasville Citrangequat I planted last year and so far it is doing great with very little protection.
I've read quite a bit about these and they sound like one of the best cold hardy types.

I am experimenting with other things:
I have some mandarins that I grew from seeds from grocery store fruit planted in the yard- they're only about a year old but seem to be doing ok (considering all the leaves have frozen off)
I am also growing kumquats from seed and will plant these out in the next year or so.
If they die or do badly, no big deal, they cost me practically nothing.

I have about 7 trifoliate orange trees scattered around my property, but these are mostly for fun, I've tasted a fruit from one of these growing in town and it was as horrible as everyone says it is.

I almost always disagree with conventional thinkers. But, consider this, Changsha is the best tasting, real hardy mandarin variety. The problem is they only stay sweet for a few days. So they may seem to be not good quality but at peak, they are fairly good. So a tree will have some in various stages at one time. That can be probalamatical if you can't tell which is which.

There is another called Clem x Yuzu 3,3 or 10 deg(F) tangerine. It is mainly used for sour citrus, slightly green, but it is O.K. in Dec. I have no idea if it it is available now days, or where. I have a seedling.

I also like Thomasville Citrangequat for sour seasoning. It is good to less than 10 Deg F.

MEIWA KUMQUATS TASTE GREAT AND YOU EAT THE WHOLE THING SO THERE IS NO MEIWA. YOU DO HAVE TO PROTECT IT BELOW 15 DEGREES OR ANY COLD WIND. iIT IS SA SMALL TREE OR BUSH SO PROTECTING IT SHOULD BE NOW PROBLEM. IF YOU CAN PLANT IT AGAINST THE SOUTH SIDE OF YOUR HOUSE AND HAVE A LEAN TO GREENHOUSE FOR WINTER YOU SHOULD DO QUITE WELL. kEEP IN MIND WHEN YOU ARE GROWING FRUIT TREES AT OR BEYOND THERE RANGE IT IS MUCH EASIER TO GROW A BUSHEL OF SMALL FRUIT THAN A 1/2 BUSHEL OF BIG FRUIT. THEN AGAIN SOME TREES ARE JUST MORE PRODUCTIVE BY GENETICS. LAST, THESE TREES HAVE A VERY HIGH FATALITY RATE AT THERE EDGE RANGE SO YOU MIGHT WANT TO GROW YOURS FROM SEED AS I DID

CLICK ON THE MEIWA KUMQUAT TREE GROWN FROM SEED TO OPEN MY DISPLAY THEN USE KEYBOARD ARROW KEYS TO NAVIGATE

{{gwi:555592}}

cousinfloyd DID YOU CHOSE SA TREE YET

I'm going to try the kumquat outside I will let u know how it goes.

I'm going to try the kumquat outside I will let u know how it goes.

{{!gwi}}

It would be a good idea to have this tent built by soon so you are not left scrambling the night of. The north-west and north-east wall can be made of lumber and insulation that you can stretch plastic over for the top and other two sides. I would have gone with a peach tree or a sweet-september cherry tree from ediblelandscaping.com. No protection, sweet cherries in august-september, on krimist 5 dwarf rootstock and it grows in the area

Cool I am going to try a hardy grapefruit tree the kumquat lost all it leaves very very cold winter doesnt usely get this cold here.

shane11, I'm new to this garden_web/houzz forum. I'd like to see the Salisbury citrumelo and live nearby, could you please post the street name or message me. If I can, I'll post some photos to illustrate how this plant stood up to the several 9 degree F nights we had in the central Piedmont of NC last winter.

Jay,

I am sorry but it has been at least 8 or so years since I have visited the tree in Salisbury. It may not help much but the tree is on the east side of 85 and quite close to 85, likely within a mile and also near an Aldi grocery store. The trees are at an older house that sets fairly close to the rd and this tree and a large citrange are both in the front yard. I am sorry I do not remember more. I will ask around and see if I can find the street name for you but it may take a while.