Leaf issues on my two elms

I have 2 elms, a Chinese Elm and a Winged Elm. This is my first ‘season’ with them, having adopted them this past winter. It was really a thrill to see them emerge from dormancy and begin to push out leaves. They were both repotted early spring, just as buds began to form.

I was expecting more explosive growth though. The Chinese elm, I pruned the long shoots in March, but a second flush ramifying those hasn’t happened. Since then, it seems just a few more shoots extended. A few leaves have spots, and I do see a few ants too. I battle pests here, aphids and the moths are the worst. So I just wonder if these trees look as vigorous as they ought to be. And if there’s anything I should be doing to maximize their health.

Close up on the Chinese Elm

Here is a close up of the Shohin winged elm. Some big healthy leaves. And some smaller yellow, curled leaves. A few have burnt tips. I didn’t prune anything. Possible overwatering? It doesn’t seem to have any pest activity that the Chinese elm has, although they are side by side.

Close up on Ulmus Alata

I think these are really special and want to give them their best life. Are my expectations getting the better of me, or should they be more vigorous?

If this was an initial repot out of nursery containers I would just let both of them grow unrestricted this year. Go ahead and fertilize to help build up strength.


I potted a young whinged elm into a small pot this spring with similar growth. The damage you are seeing may be leaf scorch based on the time of year and the pictures. Yellowing between the leaf veins and the yellowing/browning of the leaf edge are both signs of scorch. If you shade and re-hydrate now you may be able to save some of that damaged growth.

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Thanks Casteel and Roger,

I didn’t mention, the winged elm actually got knocked over in the spring so it was repotted 2x. It’s had a rough start but not doing too badly considering. I take measures to protect it from the intensity of the sun. The only shade I really get is from the building itself - no big trees to provide dappled light. East side gives full blast sun till midday, and the west side is cooler in the mornings and then a longer day of full exposure. Currently these trees are both on the eastern side. Slowly learning which trees prefer which.

Me too. I have been waiting for that temperature/humidity threshold where exposure protection is necessary. That is probably why I am so keyed up on leaf scorch. If more shade is not an option then you could try to drive up humidity with trays or putting them on the ground, There was a reply to a similar thread that mentioned using more top dressing. I have had luck doing that to slow surface evaporation. We made our first jaunt into the mid 90s today so I moved everything to less than ideal shade for now. Even in essentially full shade my elm tree used a lot of water. How old is your whinged elm? There are a lot of them growing around here and I have been curious to see when the wings form.

My impractical solution for now is to chase the shade on the balcony. Until I figure out a more sustainable solution. I have no idea how old it is, I just got it this last winter, and the wings were already there. WIkipedia says they start after a couple of years. It also says they are “the least shade-tolerant of the North American elms.” ¯_(ツ)_/¯

The winged elm is fine, that’s just the first flush of spring growth senescing. Totally normal. Something else going on with the Chinese elm.

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They grow like weeds around here and seem to do well in both shade and sun. The only foliage I have lost so far has been to caterpillars.

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Perhaps the Chinese Elm has a mild case of black spot? and the ants must be harvesting aphids like they do, although I can’t see any aphids. Just spider webs and the ants. Some leaves are damaged from caterpillars building their little shelters where they were very close together. Those guys are my worst enemy here, they attack many of my plants and love to destroy new shooting growth. BT is supposed to kill them, but only after they’ve already set up shop in the foliage. I’d love to hear any other methods that could repel them at the start so they can’t wreck things.

If it is indeed leaf spot, I have neem and copper fungicide which may help treat it, along with removing damaged leaves. Honestly neem oil has never seemed to do anything at all when I’ve tried it, so maybe I should get some mancozeb?

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How about partially defoliating the chinese elm, to remove the affected tips of the leaves with spots?

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A little over a week later now, and the winged elm is showing some spots I don’t like the looks of it.

This last one is showing some healthier unaffected leaves. The spots are on almost a quarter of the canopy and seems to be spreading.

I did a bit of cleanup and here are some better pics of the Chinese elm:

I had no luck finding specific products I’ve seen recommended here (For my variety of trees and pests I looked for Acephate, Forbid, Avid, Floramite, Mancozeb, Thiomyl, Daconil) - where to acquire these?

So this past weekend I sprayed with ‘Bioadvanced 3-in-1 Insect, Disease, and Mite Control’. Considering a followup now with Copper Fungicide which I have as well. What to do?

It does look as though you have a combination of black spot and spider mites. Both common to elms (but remember I’m only looking at photos). Good idea to spray with the bug killer first, then the fungicide and ten days later (if the insecticide allows) hit the spider mites again. They go through a ten day cycle and the next batch of eggs will have hatched. Good luck!

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Thanks Keith! This morning I went ahead and removed affected leaves and applied the fungicide. Fingers crossed. Trying to make sure they are strong, figured this is a chance to address the issue and maybe get a little more growth before the fall and the leaves drop.

Should be fine…
Remember to hit it with fungicide (sulfer…) before winter storage; and, again (daconyl…?) In spring as the buds are opening.
Took care of similar problems for me.
My problem today is yellowing on my pines. Can’t keep enough water on them at 95F+, but overwatering…:expressionless:


Kurt, would it help if you built a Suiban and placed the pines on a brick just above the water?

Thnx, were doing fine. Yellowing was hangover from wet spring.

They are shohin size. Getting morning full sun. Sitting on a low cinder block n ceader bench, just above uncut green grass. Afternoon shade.
Plenty of humidity in the bonsai garden. The slugs are loving it… My ( ‘two man size’ ) Scott’s Pine is yellow slso.
100.5F yesterday. 22% humidity.
First time its happened. Just have to learn to NOT water everything 3 tines a day… Let the pines dry out a little.
A little extra calcium, magnesium n iron applied…