Chinese Elm Leaves Turning early

[Chunky Trunks]

Hello, I repotted this Chinese Elm in May. It’s been doing great all through the summer on a bench in it’s new pot.
just started maybe a week ago any ideas?
The soil Akadama Pumice, lava rock,
one one to one ratio.
I’m assuming it’s some sort of fungus, but would also like to know how to treat. Zone 8a Matthews, North Carolina. Thank you!

 

[Bonsai Nut]

Make sure you give it enough sun, and when you water make sure you aren't keeping the leaves too wet. We've been really dry here the last couple of months, so I'm surprised to see your leaves yellowing this early (I have many Chinese elms and not a single one has started to show fall colors yet). However don't panic - just continue to provide good care and your elm will drop its leaves, go into dormancy, and rebound in the spring like a trooper.

 

[Deep Sea Diver]

Greetings

Nothing needs to be done. Looks like the tree is showing signs of paradormancy.

The leaves are getting ready to abciss as the tree has been withdrawing nutrients from the leaves. Thus the leaves are breaking down the chlorophyll etc and fungus is now able to get a foothold in the leaves.

Ours aren’t there yet, but pretty darn soon they will be looking kinda like yours!

Cheers
DSD sends

 

[Shibui]

I've seen this a few times. Usually associated with some form of stress - too dry, too wet, lack of nutrient, etc. The tree is just shutting down early, hoping things will be better in Spring. Most have grown as normal the following Spring.

 

[rockm]

Your soil mix is too lean for Chinese elm without diligent watering. As shibui points out stress can cause this. Lack of water might be the reason.

Should be better come spring but make sure it doesn’t dry out over the winter particularly in freezing weather.

 

[jeremy_norbury]

Sorry guys, but this is blackspot fungus.

I'd defoliate it and keep it away from other Chinese elms because it spreads.

You can buy a spray for treating blackspot on roses - which works on Chinese elms.

I had this a few years ago which spread to 15 Chinese elms, some even died as a result but the rest recovered over time. It kept coming back every year for about 5 years.

 

[BobbyLane]

It does indeed look like blackspot fungus. Not wetting the leaves at watering will also help to reduce it. I have overcome it with removal of infected leaves and a Lime sulphur wash. Fungicide sprays will work too.