According to this website linked below, they are hardy to zones 9 and higher. We are zone 7 (a or b).

This seed faq also says to bring them inside if the temp goes below 45 degrees.

Here is a link that might be useful: Growing avocado

Ok, I've done some research and answered some of my own questions.

I would still like some personal experience though.
I will take the risk of one or two plants this spring and let you know next winter..

CHeck it out

"West Indian varieties thrive in humid, tropical climates and freeze at or near 32° F. Guatemalan types are native to cool, high-altitude tropics and are hardy 30 - 26° F. Mexican types are native to dry subtropical plateaus and thrive in a Mediterranean climate. They are hardy 24 - 19° F. Avocados need some protection from high winds which may break the branches."

also

"Frost Protection: It is important to choose a cultivar that is hardy in your area. Mexican types are the best choice for colder regions. Plant above a slope for air drainage, or near the house for added protection. In youth, protect with rugs, towels and such spread overhead on a frame. For further protection heat with light bulbs and wrap the trunk with sponge foam. These measures also permit tender cultivars to become established in borderline locations; established trees are much hardier than young ones. The upper branches can also be top worked with hardy Mexican types, which will protect a more tender cultivar on lower branches, as well as serving as a pollinator. Harvest fruit before the frost season begins. Cold-damaged fruit turns black. Avocados are often in bloom at the time of frost and the flowers are killed, but the tree tends to rebloom. This is especially true of Mexican types. "

later!

Now you just have to figure out if you have avocados from the West Indies, or Guatemala or Mexico ...!

Good luck. It's fun to try anyway. If you like the look of avocado trees, Paw Paw (Asimina triloba)is a hardy native tree with similar foliage (large, drooping leaves).

Here is a link that might be useful: Paw Paw

Yeah, haha!

Well, I am pretty sure they are HASS avocados, which I've discovered are hardy to 25 degrees.

While searching the web for pictures of plants, I saw fruit bearing avocado trees in nice sized pots..
What I will probably do is only risk one plant outside, and keep the others in good sized pots with good soil...

They are REALLY attractive houseplants by the way... so I will make sure they don't get tall enough that I can't fit them inside the average doorway and have some awesome decorations for my house all winter.

What I'll have to do is keep them somewhat bonsai so that I can have them for the 3-7 years it will take for them to produce fruit...

PS-

I am looking for a mango tree, citrus tree, anything cool that will grow in Atlanta area.
I can work out a seed trade or even a plant trade if you want.
And if you live in the alpharetta area we could meet in person and make even more exchanges..

I have a TON of volunteer chamomile plants all over my garden so these are also up for trade.! Once again my email is firesidestrider@gmail.com

probably an avacado that comes via peru. i've grown a few avacados and have realized: first winter keep indoors (first year they can be sensitive), they love georgia humidity (expect to see most of your growth in summer and fall first two years, avacados still grow during the winter (this surprised me). wrap it in plastic if you're going to put it outside. i wouldn't worry about getting any fruit off of it for a few years.

happy growing - john

Well, What happened to your avocado trees? I'm curious to know how it turned out with the ones left outside. I have several avocados, one is over 3 years old, potted and winter is coming and they are taking over. Many are over a foot tall just from this summer. I am considering whether they might be able to survive a winter in North Georgia.

What does it mean "the upper branches can be top worked." ? and when you bonsai them, do you just nip the new leaves that come off the top? My plants are getting to be quite tall but still lanky. I have them wired so the lanky trunks don't suffer from the blasts of wind that sometimes happen. It's worked well for shaping my older plant until the trunk stiffened up and turned dark and tough.

I bought one of those 4 tier lightweight green houses with clear plastic cover from Lowes, I considered using it, but I think my trees may be too tall and bushy. I can't plant them in the ground ( apartment) and if I put them on the back wall they would have direct sun from 10am to around 4-6pm and shade before and after. They are usually in shade/indirect sun all year, but the front where they usually are stays in cold shade all winter.

I might have to set up my table indoors but I want to know how others have wintered their avocado outdoors.

Please come back and tell how it worked out.

Until late Fall, my 2 avocado trees are outdoors. This was the second season they were outside (front yard facing south where they get alot of sun) and they are about 4 feet high...one has even branched. They hang out by a sunny window in the laundry room until Spring. I did start these from some giant avocados from the International Farmer's market in Duluth. One was intentionally grown in water with toothpicks and the other sprouted from the compost pile. This next Spring they will be transplanted into larger pots as they've almost grown out of their 5 gallon pots. The main thing you want to look out for with putting avocado trees outside is possible wind damage and making sure they get enough water.

Since the year-round, outdoor cultivation of the supermarket avocado (_Persea americana_) is limited to the warmest parts of the United States, you may want to consider planting its Southeastern native cousin _Persea borbonia_, or red bay, in Zone 7 and Zone 8. Red bay is native to the Southeastern Coastal Plain from Delaware to Florida and, with time, forms a beautiful evergreen tree. Its fruit is diminutive, but very attractive. It has long oval pointed, attractively veined, glossy foliage that can be used in cooking like the more frost sensitive culinary bay. There is a lovely planting of red bay at UGA's iconic Arch on Broad Street in Athens.

Are you still conducting your avocado experiment? I just put a 2 year old one outside for the first time. It's in a 10" pot. I'm in East Cobb so it can get cold here like in the 20's for a few days.

As soon as the temps drop, any avacado tree outside here in the Atlanta area will be deader'n a door nail. They just won't make it. This is from personal experience.

I am surprised no-one picked up on a serious ERROR ! Avocado trees must come from propagated/grafted trees. With avocados, the seed from the fruit will NOT produce the same type tree as one might think. Since it takes 5-8 years for some serious production, it becomes a very serious and time consuming ERROR to plant seeds from your fruits.

How did you get your avocados to root? I have like ten seeds and haven't seen any growth!

Soak your seeds in water overnight. Gently peel the skin off the seed. Wrap them in a wet papper towel, place in a baggy and leave in a warm place. In a couple weeks it will split and root. Fill a glass of water to the rim and placing round side down touching the water. Three tooth picks place in the seed will keep it at the rim of glass with bottom in water. Now comes the tricky part. When the leaves blum at about a foot give or take, do not plant yet. Cut back about six inches and allow the leaves to blum a second time. Now you can plant.