How much water does it get? how often?
Also how is the soil there-drainage etc?

Dear yorkiemiki,
It is watered about twice a week when hot, drainage is pretty good. The soil is rocky and sandy and dries out between waterings. Maybe I shouldn't be watering at all in the summer? I just thought that with the trunk losing its width, it was a water depletion...

If the roots have rotted, it is not getting water. Twice a week water is too much for a plant that size. I am in HOT texas and even my aloes in full sun and in a pot get water once a week.

I would unearth it and see if one has roots. Is the trunk soft?? One might have to cut it down and re root the whole tree. If it still has roots, plant it back in and reframe from watering especially right after you plant it. Once this tree is established in the ground , it could get water once every 10 days to two weeks if there has been no rain. Otherwise don't water it.

How hot is hot there? Some aloes do go dormant if things are very hot. I back off a bit if I think that is so but otherwise I do water.

Dear wantonamera,
The trunk isn't soft, just shrinking width wise. The tree feels as though it is firmly in the ground but if everyone agrees that I just over watered, I will dig it up and try replanting. Anything I should look for on the roots?

Look for Soft unhealthy roots Or roots that look dehydrated. They might have rotted and then died and then dried up.. I would cut them off if you see them . Healthy roots look totally different. Some times the big guys can be bright yellow, especially on the tips. Then I would dust the roots with cinnamon ( a fungicide)let my plant rest and callus those roots in the shade , Not in dirt for several days and then replant making sure the dirt has drainage. After planting , DO NOT WATER. wait a week or at least a half week and then water. The roots if bruised in the planting process need time to heal or you introduce rot and more dead roots. If there are no roots plant and don't water till one feels resistance. I might plant it in a VERY well draining mix in a pot till it has formed roots and then plant. don't water , mist till the roots have formed. That could be a month or two.One might look at the condition of the stalk. One might need to cut the stalk back to where there is good healthy tissue. Dust with cinnamon and proceed in the pot. Some people will root tree aloes in a pot of rocks that they water. It creates a environment of hummidity and perfect drainage.

It is hard to say what is going on with the trunk. The rot in the roots might have introduced a bacteria. Maybe some spraying with Draconil or Bayers 3 in 1.

It is important for me to fessup that my experience comes from NON tree aloes. So I would get some people who grow tree aloes to add their experience. They are a bit different. There is a move afoot amonst the "SPLITTERS" to boot them out of the aloe family,get them listed as their own family.

Shrinking trunk is bad... you have a dead top there probably. I would personally chop it off below the point of shrinking. You can also safely dig it up to look at roots, too. Chopped of Aloe barberaes will sometimes regrow near the point of chopping... but not always.. .however, i am concerned that if you do nothing, you will lose the entire plant. Any water dripping on plant from overhead? If so, no more! good way to rot these. Ants can also cause a tremendous amount of bud damage indirectly by bringing in other things (like mealy bug) that can do a lot of damage. If you chop it, look for any discoloration in the trunk still remaining (at the chopped point)... if you see any, chop lower, until you get none.. .than apply root tone and/or antifungal goo to cut surface. Or buy a new aloe.. these grow really fast and you can easily replace it cheaply with a small 5 gal plant that will be this size in another 2 years.

Ok, there are bugs on the inside of the deteriorated trunk and it doesn't smell rotten. But the consensus appears to be that the only hope is to cut off the stem to healthy tissue, seal the cutting and place in rocks. Fingers crossed. Thank you.

Issdr thinks that one should most likely toss the top and the top is bad and the bottom might be good and maybe workable. And by the way, HE has a zillion aloes and many tree aloes and grows them in CA. This man knows way more than me about tree aloes. I would pay attention a to his advise and do what he says more than what I say. It carries much more weight, That is an honest appraisal of my limits.

One could chop up the top upwards from the wrinkled trunk if there is a place where it is healthy, looking for good tissue and save that. Like he said , look for completely no discoloration. Also keep some rubbing alcohol to wipe your blade after each cut so not to spread the bad juju-itus from spreading due to your doctoring.

no water dripping on top of the plant and the soil was pretty dry near the roots. Main problems appear to be as follows, shrinking trunk near the top, the trunk at the bottom near the roots is hollowing out and crumbling, there appear to be some silvery white bugs. I will follow Izrddr's advice and hope for the best.

ants sometimes farm other bugs like aphids and mealy bugs.
do the bugs look fuzzy ?

it sounds like the bugs are obviously the problem
if you can physically remove them, or even use an insecticide may the the best bet.
There are home made organic insecticides, but they never seemed to work for me.