Chinese elm - new growth shriveling & blackening

[Jaberwky17]

I have 2 Chinese Elms which I keep side by side. #1 is from the gift shop of a MN bonsai garden and #2 is mail order. #1 has been very healthy and kicking out new growth consistently for the last year I've had it, including over the winter when I kept it indoors to see how it would do. About 6 weeks ago I noticed that the growth had significantly slowed - no new shoots, only new leaves at budding nodes. About half of the new growth would start to blacken and shrivel after a week. The shriveling includes the leaves, buds, and tips of the shoots/small branches. However new growth, while slow, did not stop entirely. The tree simply looks sick. It is trying to grow but it's just not working.

#2 shows absolutely no sign of this issue, nor do any other trees (although to be fair the elms are the only deciduous in the group that I keep in this location of my deck).


Earlier this year I noticed some gnat infestation on a pine and treated it with Bonide Eight. The pine responded very well and the gnats have stayed away. This was about 2 weeks before I first noticed the issues with the elm. I only mention this because it's the only thing I can think of that is different from normal feeding, watering, and sun schedules. While I was very careful of overspray and am positive nothing got on the elm, I thought it was worth a mention.

 

[fourteener]

Sounds like a fungus, tip blight or some such problem. Treat it with a fungicide would be my suggestion. Overspray of an insecticide wouldn't cause that I'm pretty sure. I am starting to treat my collection as a whole in lieu of the upcoming storage in small spaces. I do everything I can to eliminate fungus and insect problems as all these trees are about to rub shoulders in a cold frame.

 

[lordy]

I would have a look at the roots. Sounds like they might be soggy and turning black too.

 

[GrimLore]

We thought we lost one three weeks ago with similar symptoms. It was way under potted in a 1/2 deep pot my Wife commissioned Iker to make. All the other plants on that particular shelf including Elms were fine. When every leaf was brown I asked her to slip pot it into a deeper pot surrounding her old substrate with nothing but dry stall. The roots looked very good and just yesterday noticed it is tossing out a lot of new buds that are fine. I "think" the real problem was the hotter then normal direct sun they most times love. In the old pot I am pretty certain the root temperature just went far to high to often... I do not know for certain but it is happy now with a rather simple modification.

Grimmy