Need help saving this Chinese elm!

[Krempt]

Hello everyone!

I understand that it's probably not an ideal time of the year to collect, but this Chinese elm was going to be destroyed in a community garden renovation if I didn't pick it up. During the potting process, it went through a pretty significant root reduction. After two days now, its leaves are starting to droop.

I would love some advice on what I can do to improve its chances for survival!

I'm in zone 6b, and I used a 1:1:1 soil mixture of akadama, perlite, and lava rocks.

 

[rockm]

Chinese elm is tough. The current crop of leaves will probably dry up and drop off

THAT DOES NOT MEAN THE TREE IS DEAD.

Keep the soil moist and the pot off the ground in a shady spot. Don’t let it dry out but don’t keep it wet. Wait up to a month for new buds and then new leaves. Should happen

 

[Shibui]

Chinese elms can be root pruned right through the growing season.
Leaves are drooping because water supply from the chopped roots cannot keep up with transpiration from all the leaves. The tree will try to balance water in with water out by first, restricting water supply which causes droopy shoots. If that is not enough it will shed some or all leaves to reduce transpiration. Some of the newer shoots may even die.
Rock M has already let you know that leaf drop is not death. maintain care for at last a few months as the tree will usually sprout a new set of leaves and shoots when it feels the roots have recovered enough.
Maintaining humidity can help the tree get through this trauma. When leaves are surrounded by high humidity they can't transpire as much so less call for the restricted water supply. Bagging the entire tree in plastic bag is one way. Into a closed container is another possible solution. A position protected from wind and drying sun can also help.
Try to ensure the soil does not dry out. Keep soil on the damp side but not completely soggy.

Not knowing how much root reduction it's had but I have full confidence your tree will get through this.