Adding a few additional photos: leaf closeup, soil, etc... thanks!

soil base..

Ed, the usual suspect...too much moisture for too long.

It could be because of root damage.

Many times one could under water it which cause the fine rots to die back, leaving it susceptible too root rot the next time water hits the desiccated roots.

It could be because the mix collapsed after decaying rather quickly with too many fine particles suffocating your roots system and leaving the fine feeder roots to die back from soluble salts.

Or it could be because the mix is too dense.

Or could be because your roots are over heating in that hot sun leaving them to not function and take up moisture which in turns stresses your tree. It will inhibit the moisture to leave your mix in a timely matter.

What do you think it is? You would probable know more by figuring out what culprit it is and examining the the mix up closely along with the roots.
I would also not leave my tree to exposed full hot sun.

Why are you using a saucer under the pot? Why not allow the water to drain freely away from the pot while you can?

MIke

This post was edited by meyermike_1micha on Mon, Sep 8, 14 at 9:00

"Atlanta. Metal pot. Full afternoon sun. Water every two weeks."
It could be permanently wet, but I reckon the poor thing is dying of thirst! Its probably bone dry and your water is just passing straight through without wetting the soil.
But you need to pull it out of the pot to check. Is it permanently damp or completely dry?

Thanks guys!
Mike, my fear is that your suspicions are right and I've got root rot that I need to address before I lose the tree. It thrived for the first 2 years, but I think that now the soil is compacted, isn't draining as quickly as it needs to, and the roots are suffering as a result. I realized immediately when I started reading this forum that I didn't plant it in the perfect medium to start with (I just used commercial potting soil, not knowing any better), and it's probably staying too damp for too long. FWIW I don't water it if it feels damp in the first 2-3" of soil, but that's hardly scientific.

Two questions for you guys (and everyone else in the forum):
a) is there a remedy I should try first, before traumatizing the plant by pulling it out and repotting it?
b) assuming that it's repot or lose the tree, what's the safest way to repot it to give it the best chance at a full recovery? (and how do I take care of the root rot? Just clip them off?)

Thanks!

a galvanized pot in full sun ... can get easily over 100 degrees .. probably 120 ... but just guessing ....

tree roots dont thrive in high heat ...

and also note.. the cement stays hot.. deep into the night ... which should be a cooler recovery period ....

plus everything they said about how this affects watering ...

i usually suggest in the tree forum.. to NEVER leave the pot in full sun ... the tree yes.. the pot no ...

there are many ways to do such ...

ken

ps: and those heavy salt stain on the rim of the media ... indicate that your potting media... for a tree.. is not draining fast enough .. its pooling long enough ... for salts to attack the pot ... you can do A LOT BETTER than scotts bagged media.. for trees ...

Ed, this is what I would do...

You have a few options.

Th first option is what I would do if the mix was too compacted and suffocating the roots. If you think it will get by, then options two and three would work fine.

I would remove that tree from that soil into a better draining mix asap if compacted.
I would use clay, a light colored ceramic or plastic pot.

I would use a wooden dowel that checks for moisture deep into the root zone for all options.

I would stick that tree in an area where it gets part sun until it gets use to its repot, probably into the shade.

Summer time in a very hot area is the worst time to transplant anything, especially bareroot, but if it must be done, then it must be done.

Once you use a pot that repels the hot sun rays and your tree has acclimated to a repotting, then your tree will enjoy full sun no matter where it sits...

Although as Ken said, make sure the roots cool off at night in order to do proper photosynthes...
Roots must cool at night and never over heat.
They must have oxygen just as we do in a mix that allows that.

Your second option?

You could stick that plant, pot and all, into a bigger pot full of mulch that repels the hot sun rays..The mulch or other soil mix will suck the moisture from that pot away from the bottom encouraging it to dry down better and quicker..

This will prevent a 'pwt' in your container and will encourage your roots to stay cool until your repot come next spring. It will also help your mix to dry out and stay evenly moist.
You should also flush the mix out at least once a month of accumilated salts with fresh water until you can change it in the spring.

Option three...Use the wicking method after you have flushed your mix out...

****Use option one for sure if you feel that your mix is just too dense and compacted.

MIke