I've been away due to health problems, so lets see if I can help with some advice. If this was my tree I would prune away a least 1/4 - 1/3 of the top growth of the tree, more may be needed as time go's by.
As far as watering I would water as if it was a new tree.

Is it in the sun?

If so, put it in a shady, protected location for a few weeks.
I wouldn't use compost or yard-soil in a container as both affect drainage.

Josh

Because it has already been planted into it's new site, just rig some temporary shade.

And probe the rootball a bit to make certain it's fully moist, not wet nor dry.

Plant54 has it right, prune away 1/4 to 1/3 of the foliage. It also wouldn't hurt to put it under shade cloth, as long as there is adequate air flow around the tree under the cloth. It should be treated as if it was a new plant just purchased from the nursery and installed.

Plant 54, I see that you are back and it is great to see you again..I am very sorry about your health..I hope it allows you to enjoy being here again

You've been missing and noticed..:-(

Mike..

I'm gonna jump in and encourage you NOT to do any top pruning of your tree. Removing a large amount of the foliage to compensate for root loss is a bad practice. That plants need this done to them at transplanting is a horticultural myth that should die a nice, quiet death.

Your plant NEEDS those leaves, every single one of them, in order to make all of those new roots! Not only are the leaves the factories for energy and food production for your plant, but the removal of all of those growing tips of your tree will result in exactly the kind of activity you don't want....lots of new shoots!

The new top growth will be done at the sacrifice of new root development, sorry to say. So, though we may be thrilled by seeing all of the new growth demonstrated by the transplanted tree, the true establishment process has been stymied drastically. Our woody transplants should be encouraged to grow new roots, not new shoots. Plants cannot do both things at the same time. Their response to top pruning is a dramatic one: to replace the photosynthesizing biomass that has been hacked off!

This double whammy (loss of the energy factories and the re-routing of carbon resources from the roots to the top) can be very troublesome to the plant.

In the future, know that it is no longer advised that we amend the planting hole or backfill with anything at all. Just dig a WIDE and shallow basin shaped hole, just deep enough so that your plant can sit on native soil while a couple of inches above the natural surrounding grade. The wider the hole, the better....but don't dig the hole deeper than required.

Rhizo is correct.
I certainly hope that the tree hasn't been pruned yet...

I was assuming the tree was in a container, and that it could be moved into
shade during its recuperation period. I see that I was wrong. Therefore, it
could help immensely if you provide some screening or shade during the hottest
part of the day. This will help the tree hold onto its leaves, which - as Rhizo
points out - are essential to the tree's recovery!

Josh

Thank you so much for all of the advice -- I truly appreciate it!

We are about 9 days post-transplant. I did not prune anything as of yet. It lost about 2 dozen leaves total but there still seems to be a lot of leaves on the tree. The remaining leaves, however, a very dry and brittle. I have been giving it A LOT of water every day -- I'm sure it doesn't help that we have been having a heat wave here in Orange County the last week or so. The tree gets full sun about half the day, and then shade the rest of the day.

Is there anything else I need to be doing that would help? Fertilizer? More B1?

Thanks again!

You can try both spraying and feeding some liquid kelp as per the instructions on the bottle. my local nursery told me that it acts as a "natural growth hormone" for sick transplanted or troubled plant. I have used it in the past with good results.