I live in Raleigh NC which is zone 7b, or the warmer side of zone 7. There are people growing citrus in this area but not the citrus species you've listed. New hybrids are being developed each year and there are people as far north as Virginia that have grown some of these newer types without much protection. The biggest problem is that citrus fruit take all year to ripen (grapefruit take 14 months!) and most of them ripen in the winter. So even if you can keep your tree alive the fruit will be damaged by freezing nighttime temperatures which can happen as early as late October here. South Carolina has more areas succeeding with citrus and most of them are tangerine or kumquat types of trees, not the standard lemons, limes and oranges you're interested in.

In North Carolina I would think the best areas for citrus would be along the coast but far enough inland to avoid salt spray (salty air travels quite a ways inland from the beach and lots of plants hate it). If you drive along the south coastline you rarely see any citrus in peoples yards or gardens.

In most of zone 8 it gets hot early (not this year). So a lot of the standard garden vegetables are getting ready to pick in June and July which are usually the hottest part of the year.

Even in zone 9a growing citrus is considered problematic:
http://forums.gardenweb.com/forums/load/citrus/msg1117294324120.html

There is only a small number of 'special' varieties that could grow without protection in zone 8.

Here is a link that might be useful: Cold Hardy Citrus

Here in Raleigh we have two Poncirus x Citrus hybrids (one is "Dunstan) at the J C Raulston Arboretum that are about 4 years old and about ten feet tall. They bear fruit heavily and are edible but not close to being as good as their citrus parent. I have a Mandaran orange that is about 6 feet tall but has not yet fruited, but has been hardy outdoors for the past 5 years.
As for growing veggies here, many, many cool weather crops can be started in September and overwintered using frost cloth covers. A few of them may require additional plastic covers on nights that it gets into the low 20's or lower. The past two winters have seen a low of just under 20 F, but lows near 10 used to be common.

If you're willing to grow in pots, and have a sunny location to bring them indoors in the winter, then they are fairly easy to grow here, and are being grown as far north as Canada; I've even seen someone succeeding in Greenland, but he uses heavy grow lights. I'm growing lemons, oranges, grapefruit, and a lime tree. If you want to put them in the ground, you will need extensive protection to grow anywhere in NC. Even the cold tolerant varieties like the Satsuma orange will only survive winter outdoors around the SE coast of NC.

I've a crazy gardener friend here in Fayetteville NC

who has a lemon tree , outside, about 20 years old. She picked bushels of lemons on Thursday and I was the recipient of about 40 lbs of them. They do nothing for overwintering. About 5 years ago I started a baby with some of the yearly stash and it too is outside doing great with no winter protection. I'm hoping to get a few lemons this year for comparison as I have no idea if its some hybrid or what cultivar it is. They are great tasting about the size of a medium orange.

I can save some seeds or start some seedlings if interested.

I would love some seed. We have some citrus x Poncirus hybrids doing well at the J. C. Raulston Arboretum, but the quality of the fruit is not great. It would be very interesting if you can find out anything about the history of this lemon tree because it may be something special if it is a seedling lemon tree and not a hybrid of Poncirus. If your seedling produces similar fruit I would guess that it is not a hybrid. How large is the tree? Does the fruit typically ripen before the first fall freeze and do the blossoms get killed by late spring frosts some years? If so, do you think that it could be kept small enough by pruning so that it could be grown in a large pot?

Things I do know is it was bought at a small nursery in Florida over 25 years ago, she bought 3 small trees and 2 did not survive. It took almost 10 years to produce first fruit but has had a yearly harvest ever since. It isn't deciduous like the Poncirus. It blooms late enough in the Spring that even a late frost hasn't affected it. She said yes, they turn yellow right before first frost.

It's about 15-20 ft tall.

I'm going to try my darnest to get some cuttings this Spring and try my luck cloning. Not as easy as one may think. She had bought the tree for her mom- who she lives with- but the mom doesn't share- not even pruning material. Nothing I've offered so far has softened her up!

I'll try and get some babies started in Jan,,

My 2 cents (about all its worth sometimes) - Most true lemons are frost tender and Meyer lemons are even more sensitive to cold, so I doubt this is a true lemon. Most citrus trees available at nurseries are grafted and it used to be that they were grafted on to Poncirus trifoliata 'Flying Dragon' because it kept the trees short. But nowadays more are grafted onto Poncirus hybrids like 'Dunstan', a grapefruit crossed with Poncirus or a hybrid of Poncirus crossed with orange. The fruit these trees produce is highly variable, some will retain some of the bitterness from the Poncirus genes and some will be big and round like a grapefruit and some will be very lemon like even though there is no lemon in the bloodline. A lot of the citrus fruits we like to eat are actually hybrids (some occurred naturally, others were man-made) so keep in mind that this group of trees will cross breed like crazy. It turns out that using 'Flying Dragon' or regular Poncirus trifoliata as a root stock has its problems, namely that the graft will eventually fail usually around 10 years time. Using one of the other hybrids as root stock does not seem to have this problem.

What happens most often this far north is that the top growth, the "lemon tree" part dies when exposed to cold temps but the root stock survives and continues to grow. Because the genetics are so mixed up the root stock's leaves and fruit can appear to be a lemon or an orange or a grapefruit. Sometimes the fruit is edible and sometimes it isn't, most often it still has a hint of the Poncirus resin flavor (very bitter) but sometimes it doesn't. There are trees in this area that fruit every year with edible fruit but the flavor is weaker than a normal lemon or orange.

Keep in mind that a lot of citrus have a problem when grown from seed - they get locked into a juvenile stage where they grow like crazy and look nice and healthy but fail to bloom and fruit. It can take them up to 15 years to become fully mature. So prepare to wait a while if you attempt to grow these from seed. Grafting onto hardy root stock would be the best plan. Most citrus shut down when soil temps get below 50 degrees so I would wait until early summer to attempt the graft.

There are two Poincirus x citrus trees at the J C Raulston Arboretum. One looks like a lemon but tastes very sour and has a distinctive Poinciris resin taste. Laura, if your neighbor's tree tastes like lemon and has some sweetness, it has promise as something special for those of us interested in growing citrus here in N C.

Ralph,

Im heading to the post office tomorrow, would you like a few lemons? I know nothing about citrus.... That will give you seeds if you like them, and tell me if it's worth doing some grafting this Spring.

Throw Me your address and I'll get them to you.

"

There are some citrus varieties that can survive in ground in NC. Check out Mckenzie farms in SC (website HERE) for some good citrus options.

I have 2 citrumelos (probably 'dunstan') outside here in NC zone 7b. The are about 6-7 years old. Grown from seed from a tree in Winston Salem so they still have a while before blooms/fruit.

A cold hardy lemon (that taste like a lemon) would make some news in the citrus world. I sure wouldn't mind getting a cutting of it! The lemons in that picture look a little too round to me to be a regular lemon, but I'm not a lemon expert...

5124 Norman Place - Raleigh 27606. I will let you know how they compare to the "Lemon" tree at the arboretum. Thanks.

A poster on the Citrus forum says the lemon fruit in the above picture looks exactly like an "Ichang lemon". After googling it, I think it does too. It's pretty cold hardy.

A close up photo of the leaves should clear things up. The Raulston Arboretum used to grow Ichang Lemon but they froze out a couple of years ago. I had some in the ground and mine froze back. I think I still have one in a pot somewhere...I dug everything up one spring after back-to-back hard winters.

How does the Ichang Lemon compare in taste to a regular lemon, like a grocery store lemon? I may try planting one down here. Next spring I'm planning to plant some cold hardy citrus. All of mine are in pots right now. my citrumelos are in pots, but stay outside.

I don't remember tasting it but I do remember the staff saying that some people thought it made better lemon pie than real lemons whereas other people could detect a hint of the bitterness found in most cold hardy citrus.

I have made pie from the hybrids at the arboretum and it tasted fine, kinda like a lemon pie with a dash of grapefruit.

The big problem with cold hardy citrus is that most of them ripen their fruit in the winter - so the tree might survive but the fruit is ruined by freezing and thawing over and over. Satsumas make the most sense because they ripen in November and are pretty cold hardy.

Those who insist on fruit tastiness as a high priority might consider some of citrus dwarf varieties, which perform very well even in relatively small containers.

Our Citrus 'Valencia' flowers abundantly and produces oranges already in
a 12" container. Pictured in March 2016: mature oranges one year old from
pollination in the previous winter and immature ones from summer 2015
pollination. It shows excellent drought and heat tolerance, sitting the whole summer on a south-facing deck. It also handles very well being kept during winter as a house plant.

Beautiful tree! Looks like you take care of it well. I've never had a Valencia. Heard they taste great. I have some satsumas, they do well in pots in NC. Thanks for sharing your pic.

We germinated several of our Valencia seeds (the oranges do taste great - differently than the monopolistic navels from the produce section) and we still have a number of seedlings for trades at the Raleigh Plant Swap. Most citrus seeds come true to type because of nucellar embryony, although - as always pointed out by TriangleJohn and discussed here - it will be several years until the seedlings mature to produce fruit (5-7 years for oranges).

One of the characteristics of the nucellar seeds is that they contain multiple embryos that germinate together:

but can easily be separated after several weeks:

interesting. Those seeds look much darker that the ones from my citrus trees. Almost like a peanut. I sprouted some calamondin seeds last year, and all seeds produced more that one seedling. One had 5. Now I have so many Calamondins, I will have some to swap/give away if I get to go to the next plant swap.

What type potting mix do you use for your orange tree, CasaLester?

The seeds are dark because their light yellow fibrous hulls were very loose after soaking and were removed. When this tree was first re-potted, it was put into the big-box store "potting soil". Now we are upgrading our potted tropicals to a home-made mix of about 4 parts soil conditioner (aged pine bark fines), 3 parts native clay soil, 1 part big-box "garden" soil, 1 part home-made compost (aged 1-2 years), and 1 part coffee grounds.

I'm interested in trying citrus in pots but think I'd have trouble overwintering them inside. My house is not very sunny inside, and I bet there would be a spider mite problem. Is your house very bright , CaraLester? Do your plants go dormant or stay in active growth?

I went by the JC Raulston Arboretum Thursday in advance of the big freeze this weekend thinking I might "rescue" some of the hardy citrus from the 2 trees there. The grapefruit-like Dunstan had all fallen off and were visibly in bad shape. The others which look like lemons were still hanging on the tree in large numbers and looked good. But as John stated several postings ago, they had already been ruined by the previous low temperatures we have had. Lorabel, you neighbor's "Lemon" tree still sounds like something very special.

I picked a few early last month from the poncirus/orange cross (not the 'Dunstan'). I have them in my fridge. I may get around to tasting them today. Sometimes if you pick the regular Poncirus fruit and store it in the fridge for a month it loses most of that harsh resin taste.

Erasmus_gw,

The living room where we have our potted citrus is very bright - south-facing, with the whole outside wall windowed, plus two skylights. The tree is forming flower buds right now:

If a potted citrus is kept outside in full sun for the whole growing season and brought inside only between November and March, it may be able to accumulate enough energy to compensate for the darker winter environment.

The tree looks good, CasaLester. That's what I do, bring mine in from November to March. I have seedlings under lights, but everything else by windows. Had no winter leaf drop this year. Some Ive been moving outside daily all year, on days when it's warm enough and sunny. This week I'm leaving my more cold hardy ones out over night. Growing citrus in NC takes some effort, but I enjoy it.

i left my citrumelos outside over this last winter blast (under cover) Looks like they made it through.

That's a pretty tree, Casalester. Sounds like it's worth trying.

I have a Meyer lemon that I have grown from a seed and a navel orange that I bought in fla. they live on my back porch all spring and summer doing great and growing ..I have brought them in and the orange has dropped all of its leaves.. the Meyer isn’t looking well either.. help!! What’s wrong? I’m a novice citrus grower. Contemplating a greenhouse ginger

We see some leaf drop on our 'Valencia' if it is exposed to freezing temperatures before being brought in. Sometimes we do this on purpose to kill scales - it is cold tolerant to 28 F and recovers well already during winter. No leaf drop this year as it was brought in ahead of the first freeze.

Moving Citrus into much lower light conditions may exacerbate the leaf drop problem.

I tasted my only 'Dunstan' hybrid citrus today. The fruit fell off the tree last month and I have ignored it up until today. I think the long wait improved its flavor! This is a hybrid between grapefruit and Poncirus trifoliata. The fruit is round and orange sized but matures to yellow (like its grapefruit parent). I also have a huge Poncirus tree that came with the house (maybe 60 years old. it's BIG!) and I have noticed that if you store the fruit for a month it will reduce the resinous flavor. The 'Dunstan' tasted like super strong grapefruit. If you mix it half and half with water and then sweeten it heavily with sugar and add a pinch of baking soda it is like rich grapefruit juice. In my mind it is better than standard grapefruit juice.

Someone is giving away a large potted citrus:
https://raleigh.craigslist.org/zip/d/free-lime-tree/6767827384.html