Hi! I'm new to this forum, though I found it and starting reading it last March for this exact question. This is the only topic I can add my experience to so far! Sorry to be long winded, but I care about the plant that taught me about this.

While working at a garden center twelve years ago, some customers recently relocated from Texas asked if I'd like to have their then 20 year-old container grown grapefruit tree. Sure! Such a pretty tree -- great trunk. It was in a half-barrel, the soil totally shot, holding no moisture. And the tree looked stressed. I potted it way up in the largest, tough plastic pot I could find where I worked. No idea the size. It bounded back for a good while. I pulled it in and out of the garage all winter for over ten years, top dressing and fertilizing. But it never grew much more than six feet (don't know if rootstock matters for citrus height). It would flower like crazy, but never set fruit and seemed to get more stressed again.

Last March, it looked like it would seriously give up soon. It was already so heavy for me and I didn't want to lose it after all this time. Like others explained, the medium was completely shot under the top dressing. So I found the best gem micro-climate in my yard and read everything I could find on-line. I knew it was a huge risk, but I planted it outside following all the best mix of directions I found. Lucky we haven't gotten too cold yet, but it has old-school lights on it, hardened it off and I cover it when it seems necessary. No damage at all so far. Fingers crossed!!

It's certainly stunted. It spent all last summer with healthy leaves (sun leaves?) clothing the trunk, but no new outward branches. I think the shock and need for serious root growth took priority. Again sorry to be so long winded, but I say all this because I feel very strongly that in-ground is the long term way for me to grow. I've begun only buying colder hardy plants from Stan. And though I've seen many gorgeous, tempting plants on this site, lacking a greenhouse, my grapefruit has truly set me off of container citrus. If someday I lose it, I'll be very sad, but I know it's soooo much happier now.

All the Best,

Brigid

how cold can it get in Atlanta

Hi Brigid !

No sweat !
If snow hardly makes it to the ground and even if, melting soon away, you have lots of citrus that you can grow safely.

My first suggestion is Kumquat.

and Unshiu.

Adriano, I looked up temperatures on NOAA and have some averages from last year for you below. I wish I could find the averages for 2010 that people said was cold, but they don't list it anymore except in 1981-2010 averages. Last, year I wore sweaters at most in the winter. We have had crazy record lows below 0F but not since the early 80s. Our city is so huge now compared to then (new micro-climates?). 2013 is already placing in the top high records at 76F a few days ago. Last summer was brutal at some points. I use NOAA to get my weather reports. Many times, I've noticed that it can be almost ten degrees warmer where I am than wherever they are measuring. Sorry I can't seem to make the spacing pretty. I hope it is okay.

Lowest Daily Minimum Temperature (degrees F) Year: 2012
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
22 19 34 40 53 55 70 63 50 40 30 30

Highest Daily Maximum Temperature (degrees F) Year: 2012
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
71 76 84 88 93 106 105 99 92 83 81 74

Lowest Daily Average Temperature (degrees F) Year: 2012
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
28.5 29.5 46.5 51.5 63.0 66.5 77.5 75.5 64.0 48.5 43.5 37.5

Highest Daily Average Temperature (degrees F) Year: 2012
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
62.0 68.5 72.5 76.5 81.5 91.0 92.0 86.5 82.5 71.0 65.0 64.5

And thank you for the suggestions, Sanguinello and Adriano!! I will highly consider them. So far I have recently bought an Owari mikan and a yuzu.

Side note: much of my family moved to the US from around where both of you live. But lots of different villages, not cities like you. My mom didn't learn the languages, but I can speak a tiny bit of Croatian/Bosnian with the older members. Tiny bit!

Lol Brigid !

The Kingdom of Croatia was part of our empirer, but we speak GERMAN ...

Owari is already an Unshui/Satsuma ...

Haha, Sanguinello! Yes, they are from so many places in the old empire and spoke many different languages -- German, Slavic, Polish, Ukrainian. They all met up when they came here.

I thought C. unshiu was mikan, but didn't check. Thank you! I think I will get a few more varieties of unshiu.

... and mine all met in Vienna, the capital of the empirer ..

Unshui is the name of the province in Japan, Satsuma the dirstrict.
The latin/schientific name is Citrus unshui, while the common name is Satsuma.

Owari and Mikan are the name of different sorts.

Lucky! Lol, I love where I live, but...

Mikan is the only word I knew because it is the name in Japanese that I learned when I was there. Thank you for explaining the rest! Is satsuma the most common word to use? Like naming types, I would say Miyagawa satsuma or Owari satsuma?

Satsumas are the typically Christmas Mandarines you know.

All the sweet Mandarines from Japan are Satsumas.

The diference to the European Meridien Mandarine is a very sweet and intensive, but comparedly shallow taste.

The Meridien Mandarine has a much finer and eloborated aroma, but is less sweet.

The Clementine is cross by accident of Meridien and a Bitter Orange is even sweeter and has a very fine profumed aroma.

...