Chinese Elm has brown spots

[Shibui]

SoCal is probably close to frost free so Chinese elm may not be deciduous. I'm told that growers in warmer climes repot and root prune Chinese elm any time of year because they just never have a dormant time. I'm confident yours will be OK.

 

[Wulfskaar]

SoCal is probably close to frost free so Chinese elm may not be deciduous. I'm told that growers in warmer climes repot and root prune Chinese elm any time of year because they just never have a dormant time. I'm confident yours will be OK.

Thanks Shibui. You're exactly right. I just found some large elm trees (not sure if Chinese) in a parking lot that still have all of their leaves.

 

[Wulfskaar]

The buds are popping open only a few days after repotting.

 

[Wulfskaar]

Thanks Shibui. You're exactly right. I just found some large elm trees (not sure if Chinese) in a parking lot that still have all of their leaves.

Correction! I found pictures of large elms right down the street in winter and they were mostly bare. My guess is it depends on the weather that year.

 

[Wulfskaar]

Shortly after the picture above was taken, the newly budded leaves stopped growing and started turning darker with a little brown. I think it may have been due to the repot with cooler temps.

Now, newer leaves have emerged from the same buds and are overtaking the older ones. I was a bit worried but it's good to see the new leaves coming in.

January 2022: New leaves not looking good.



Feb 2022: Even newer leaves coming in and looking much better.

 

[Froggy]

Shortly after the picture above was taken, the newly budded leaves stopped growing and started turning darker with a little brown. I think it may have been due to the repot with cooler temps.

Now, newer leaves have emerged from the same buds and are overtaking the older ones. I was a bit worried but it's good to see the new leaves coming in.

January 2022: New leaves not looking good.
View attachment 420625


Feb 2022: Even newer leaves coming in and looking much better.
View attachment 420624

Hello! I also have a chinese elm with nearly identical spots on it. Have you noticed any spots on the new leaves that just grew in?

My tree had similar spots last year and it went dormant over the winter, lost all its leaves, and has since grown entirely new leaves. The spots have come back though and I still don't know what's causing them.

 

[Wulfskaar]

Hello! I also have a chinese elm with nearly identical spots on it. Have you noticed any spots on the new leaves that just grew in?

My tree had similar spots last year and it went dormant over the winter, lost all its leaves, and has since grown entirely new leaves. The spots have come back though and I still don't know what's causing them.

Hi Froggy!

No, thankfully not so far. I did change the soil to bonsai soil, but it's also still early. I will be looking closely over the spring/summer again for the dots.

 

[Wulfskaar]

Here is a current picture. It's growing very nicely so far this spring.

 

[hemmy]

Here is a current picture. It's growing very nicely so far this spring.

I looked at your first pics and I have had identical black spots on my chinese elms. Mine did not look like the @jeremy_norbury pic. Over time the leaves tend to yellow. They were in a range of mixes from peat to pumice/bark to akadama. I believe it was fungal. Over the years I have treated with mancozeb, daconil and copper at various times throughout the year (the benefit of our arid climate is that it doesn’t wash off!). They all seemed to be effective as a preventative. I also was more careful with overhead watering. Now I usually see it on some scattered leaves around the garden in the late summer or early fall. I remove the few leaves as I see it to avoid having take off too much at once, although elms could take it fine.

I started acidifying my water a couple years ago which took care of some nutrient lock deficiencies and I think that also helped strengthen the trees to fight off fungal attack.

 

[Wulfskaar]

I looked at your first pics and I have had identical black spots on my chinese elms. Mine did not look like the @jeremy_norbury pic. Over time the leaves tend to yellow. They were in a range of mixes from peat to pumice/bark to akadama. I believe it was fungal. Over the years I have treated with mancozeb, daconil and copper at various times throughout the year (the benefit of our arid climate is that it doesn’t wash off!). They all seemed to be effective as a preventative. I also was more careful with overhead watering. Now I usually see it on some scattered leaves around the garden in the late summer or early fall. I remove the few leaves as I see it to avoid having take off too much at once, although elms could take it fine.

I started acidifying my water a couple years ago which took care of some nutrient lock deficiencies and I think that also helped strengthen the trees to fight off fungal attack.

That's very useful info coming from someone in my own county. Thanks!

 

[hemmy]

That's very useful info coming from someone in my own county. Thanks!

Your picture from Post #23 reminded me of mine. But I couldn’t find any good pictures showing the spots. I did have these posted on the below thread which show some of the discoloration. It seems to be a chicken or the egg scenario. Does the fungus with the black fruiting bodies also cause the discoloration or is it chlorotic from a nutrient deficiency and the fungus takes advantage of that condition. Full disclosure, I haven’t sprayed any fungicides yet this year on deciduous or pines. But if it looks like no more rain is in the forecast, then I will probably spray within the next couple of days to take care of any spores that might be in air from this last rain.

Post in thread 'Hellppp!!!! Yesterday it was fine!'
https://www.bonsainut.com/threads/hellppp-yesterday-it-was-fine.34113/post-576722

 

[Wulfskaar]

I moved this out of direct, hot sun and put into dappled sun. It's been doing really good.

 

[Wulfskaar]

Here it is with fall colors!

The on branch you see on the left going up and out of the picture basically grew about 4 feet this year. Should I keep that branch next year to allow for further thickening of the trunk, or can I chop that off and expect more growth in the part that I originally planned as a trunk that has very loose wiring around it?

The reason I ask is because the curvy part didn't really grow much. Almost all of the growth happened with that one long branch.

 

[jeremy_norbury]

Depends what your design goals are.

If you don't want to grow a pole, then I'd suggest you need to wire movement into the trunk already.

This pot is too small to successfully grow a decent trunk in - they need planting in open ground for that.

 

[Wulfskaar]

Depends what your design goals are.

If you don't want to grow a pole, then I'd suggest you need to wire movement into the trunk already.

This pot is too small to successfully grow a decent trunk in - they need planting in open ground for that.

Thanks Jeremy. The smaller part is actually wired as the trunk. The branch in question went nuts and grew 4' over the summer, while the "trunk" remained small and curvy.

I know I've got A LOT of time and repottings until the trunk is thick enough, but was wondering if cutting off the long 4' branch was a bad idea or not.

 

[jeremy_norbury]

Thanks Jeremy. The smaller part is actually wired as the trunk. The branch in question went nuts and grew 4' over the summer, while the "trunk" remained small and curvy.

I know I've got A LOT of time and repottings until the trunk is thick enough, but was wondering if cutting off the long 4' branch was a bad idea or not.

Cutting off ANY branches has the opposite effect of trying to grow a trunk.

 

[Wulfskaar]

Cutting off ANY branches has the opposite effect of trying to grow a trunk.

Thanks again Jeremy.

I realize that I need to let it grow, and that's what I'm going to do.

Please humor me on this hypothetical:

I still have the same questions in my head... If I don't cut the long runner, will the part I wanted to be the trunk not grow again? What was once the wired trunk is now a branch.

If I did cut it off (I know you're saying don't cut it), while slowing down overall thickening of the trunk, would it not help to increase taper? Even if it slows the overall thickening?

 

[Wulfskaar]

UPDATE: My Chinese Elm is about 6 ft tall now and about as fat as my pinky finger. The fall colors weren't great this year, so I never got pics. I might repot in spring into a grow box or something and work the roots a little.



Here's how it started.

 

[Wulfskaar]

Repotted today, although I made a rookie mistake and I'm not sure what to do.

The tree was a 6 foot pencil thin whip before today.

Took off lower roots and tried to spread them out for nebari development. Everything was looking good, until it wouldn't stand up because it was so top heavy. I didn't tie it down to the pot. I ended up chopping the top 3-4 feet off the trunk, as I always pictured using the lower branch as a trunk. Now it's kind of leaning a bit.

Is it ok to chop now that the buds are beginning to swell??? I'd love to chop lower get rid of the super straight and long pencil trunk. If not, when would be a better time?

 

[Shibui]

Nice work on the roots. I would probably have chopped the remaining roots much shorter to encourage more root ramification closer to the trunk but that can be done another time if you mant to do it.
No problem chopping a Chinese elm at repotting time.
Chinese elm can be chopped as low as you like. Elms have the ability to throw new buds from the trunk and from the exposed cambium at the chop site so there's no real need to restrict chops to a side shoot or branch.
If the trunk is still unstable you can tie it to the outside of the pot. I sometimes use twine or wire wrapped around and under the pot then around the trunk. If the lean is only in one direction a simple wire hook from the trunk to the rim of the pot may be enough. Your tie down only needs to be in place long enough for the new roots to grow into the soil - maybe 3-6 months, depending on conditions, etc.