Since there are at least 9 different growing zones in Ga., it would help a WHOLE lot to know which area you are in. I'm way down in S.W. and I plant mine in Jan. or Feb. depending on the weather. And mine are planted in the ground.

I'm S.W. of Atlanta in Jonesboro/Stockbridge area....

It would have been too hot to plant in July but now that it's cooling down you might have more luck. I tried my first crop this year and needed a lot of advice but all of my seed potatoes provided a good harvest for me in Decatur.

I tried some in cheap Black Magic soil from Big Lots, they came up but that soil is pretty awful as every other plant/vegetable/flower did quite poorly in it and visibly improved when I changed the soil (some Miracle Grow, some Vigoro). The potatoes planted in better soil also grew larger than those in the Black Magic.

To answer the first part of your question I'd say any commercial bagged soil will do if you're just having fun. If you want a real harvest then the soil does matter and you should get one of the better brands.

I mixed Black Kow bagged compost in with the soil at a ratio of 1 part compost to six parts soil. I read that too much compost can cause scab but this only happened with one variety of potato (German Butterball). I also fertilized once a month with a mix of fish fertilizer and seaweed (both Neptune's Harvest brand).

I grew my potatoes in fabric grow bags (cheap on Amazon). I also grew some in baskets from the $1 Store that I lined with a net laundry bag (also $1) to keep the dirt from washing out - both were just fine. Containers that had more than five seed potatoes provided many small potatoes. For me, I got the best combination of size and count with three seed potatoes per container.

I didn't realize the plants would go yellow almost overnight without ever really flowering. I got help here on GW and from the seller of the seed potatoes AFTER I went a little nuts trying to figure out what demon bug attacked my plants. My advice: relax if the plants are growing healthy, death of the greenery is natural and THEN you get potatoes :)

I'll be starting my second container crop in mid-October. If you try an early variety you can have potatoes for Christmas.

I'm so glad I was able to actually answer a question for once I may have rambled a bit but I hope you find something useful.

This is a little late for this past summer planting season. I am in Brooks, Ga (just south of Fayetteville). We are pretty close and would have the same weather. A good resource for you is Swints in Jonesboro near the Dairy Queen. They sell seed potatoes and the old timer there usually gives me lots of help. I planted my potatoes on 3/9 and harvested them on 6/12. We had a really rainy spring and I was not sure when to plant them. I guess I did okay on the planting date. Can't help you with container gardening.