I saw my Chinese Elm was showing signs of root water-rot, and appearing to be slowly dying one leaf and one branch at a time - surviving rather than thriving. This tree experienced a winter that averaged 40 degrees, and never getting to dormant [and a caretaker who just kept the soil to wet during the winter] with the small pot-bound tree showing it was cramped up and not doing well when I peeked under the surface. Have read Spring/early Summer are go-to repotting seasons - so I repotted my Chinese Elm in a larger pot in early Summer.  I cleaned and trimmed the roots to remove the dark colored and packed root pack - and repotted in a larger pot with fertilizer and layered bonsai soils as seen and suggested by other growers. The tree resides in our sunroom with bright direct light for a few hours in the morning - indirect light remainder of the day [I have been babysitting with extra light during the root. Keeping an eye on my bonsai tree - it has been hot [in the 90's end of JUN. and JUL. is looking to be as hot [or hotter].

Lesson learned - Need to water sparingly after this repotting. Instead of drowning find the balance of moisture and dryness that works for the tree. The intent is to keep the soil moist when needed - but not waterlogged [I want to avoid the root rot this tree experienced at my hand previously]. Have posted a series of images. The first five images posted are of my Chinese Elm  tree immediately after I repotted it [near death] in a slightly larger pot [after its winter of discontent]. Then sharing images of how it is reviving today. I am pleased with the amount of leaf growth spreading. 

Was unsettling when I saw the branches shrink and drying out.

I would expect a newly repotted chinese elm to have 30-40 cm long growths by this time of the year and it should be time for first seasonal pruning. What I do differently from what you did:

I never put fertilizer on newly repotted trees. Not until growth has expanded at least 10 cm.
I water abundantly every 1-3 days in the summer. But I live in an area that very seldom see temperatures above 25. Most people need to water daily or bi daily in warmer places.
I always keep a newly repotted tree in almost full shade until it is growing well. After it has recovered it can be moved direct into full sun.

Good luck with your tree.

It should not be inside either.

It looks like a netted patio to me. Quite common in the states to keep the mosquitos away. If that is the case, the environment is quite similar to outdoors and suitable for the tree. If it is glased, I agree with Geoff, take it outdoors.

Hey Topfrog - A response [Thanks!]

"I would expect a newly repotted chinese elm to have 30-40 cm long growths by this time of the year and it should be time for first seasonal pruning."

dhelix33: This tree had most growth dropping off or gone completely from over watering root rot before repotting a couple weeks ago. Getting some new growth in a couple weeks [see images]. However, in just two weeks of recovery, this growth is long from growth of up to 16-inches as you indicated in a "newly repotted chinese elm" as indicated in your comment. Also agree that a trim is needed - want to see how many branches recover before cutting - another week maybe. 

"What I do differently from what you did:

I never put fertilizer on newly repotted trees. Not until growth has expanded at least 10 cm."

dhelix33: I did lay a little fertilizer while repotting. Alas, I too saw after the fact  recently potted or repotted plants do not benefit from fertilizer. Fresh potting mix is packed with nutrients yet to use. My hope is I have not potentially damaged my recently repotted bonsai - suggestion is to wait 2–3 months after repotting before fertilizing actively growing plants during the growing season. Fingers crossed! 

"I water abundantly every 1-3 days in the summer. But I live in an area that very seldom see temperatures above 25."

dhelix33: I live in an area of the US [North Carolina] where average high temperatures range from mid-80s to mid-90s [Fahrenheit]. That being said, I will be keeping an eye on finding a right balance for watering in this humid location [Summer and Winter].

"Most people need to water daily or bi daily in warmer places."

dhelix33: Over watering is what go the tree unwell in the first place, don't see me watering daily or twice a day moving forward.

"I always keep a newly repotted tree in almost full shade until it is growing well. After it has recovered it can be moved direct into full sun."

dhelix33: Prior to the root rot, I gave this Chinese Elm a balance of light, not too much or too little. Yes, too much sun can stress the tree, while too little can limit its ability to flower. Full sun encourages robust growth, while putting in partial shade can still yield a healthy tree.

This tree is technically not indoors - it is in a screened sunroom.

Going to keep it in our screened-in sunroom year round.

dhelix33 wrote: Hey Topfrog - A response [Thanks!]

Also agree that a trim is needed - want to see how many branches recover before cutting - another week maybe. 

I think you got me wrong here. I did not say your tree is ready for pruning, not now and not in a week. Bonsai is a maraton, not a sprint. It needs to grow before pruning. As said, 30-40 cm. There is not a chanse it will do that in a week. Maybe if you do get the care right and gets a good response it will be ready to prune come next late spring to early summer. For now it just needs to grow wild and recover.

Oh, yes. I do not believe your tree was suffering from overwatering in june. In my experience it is not possible to overwater chinese elms in summer. Most likelly the repot was not needed and gave the tree unnecessary stress by repotting in the wrong season.

Check this video out with extensive information about chinese elm bonsai, very useful information:

Topfrog -

I mentioned that this root rot was discovered after a winter here that averaged 40 degrees [and not allowing the to become dormant - and me over watering]. I saw the small pot-bound tree showing it was cramped up and not doing well when I peeked under the surface and found dark roots.