Japanese Maple Help: Mangled Irregular Leaves, some tips browning

[BeneficialCucumber]

All the leaves on my Japanese Maple are growing mangled and irregular, also lots of browned tips, does anyone know what could be going on?

 

[Colorado]

I don’t know what causes it, but I seem to deal with this every year on Japanese maples in the late summer. It doesn’t seem to have any significant impact other than looking unsightly for a few months.

I think it may be related to desiccation from hot, dry wind, when the tender new leaves are emerging. That’s my best guess anyway.

 

[BeneficialCucumber]

I don’t know what causes it, but I seem to deal with this every year on Japanese maples in the late summer. It doesn’t seem to have any significant impact other than looking unsightly for a few months.

I think it may be related to desiccation from hot, dry wind, when the tender new leaves are emerging. That’s my best guess anyway.

thanks! that could be it, the tree looks healthy except for that. It's not sunscorched as I've been keeping it in half shade and overwatering is probably not it either as the soil dries pretty quickly now

 

[19Mateo83]

I get the same crinkled leaves, it doesn’t seem to effect anything other than looks.

 

[Wulfskaar]

I'm getting that on several different species, including Japanese Maple. Good to know it's probably not some deadly disease.

 

[Rivian]

it doesn’t seem to effect anything other than looks.

well, we are growing them for looks, I dare say

I have the same issue. It varies between varieties and is caused at least in part by intense sun

 

[penumbra]

Almost anyone with Japanese maple cultivars in pots will have this problem. And it is almost always mid to late summer. Still, I find the reward of the spring emergence of leaves to be worth it, with a fall color up and and beautiful winter silhouette as a bonus.
I would imagine the reasons can vary for a number of reasons. And incidentally, my maples in the ground don't have this problem.

 

[Rivian]

my maples in the ground don't have this problem.

thats where it gets interesting.

 

[penumbra]

thats where it gets interesting.

Interesting, yes indeed, but as should be expected. When a plant is grown in the ground it acclimates much better to its environs. To some degree a potted maple will acclimate over time. The maples I have had the longest look the best. That is unless I have failed to do my part, water, spray, fertilize etc.

 

[Firstflush]

Could be what others have said. Aphids will do that too: Every attack on my JM by aphids this year is shown all the way out to the end of the branch....about 3 clusters on each branch.

 

[Mellow Mullet]

It is a fungus, anthracnose.

 

[nuttiest]

sometimes calcium deficiency can look the same. It is easy to get calcium deficiency if you use magnesium sulfate regularly.

 

[Mellow Mullet]

It is a fungus, anthracnose

Anthracnose of shade trees

How to identify anthracnose

extension.umn.edu

 

[Haxor Dave]

I don’t know what causes it, but I seem to deal with this every year on Japanese maples in the late summer. It doesn’t seem to have any significant impact other than looking unsightly for a few months.

I think it may be related to desiccation from hot, dry wind, when the tender new leaves are emerging. That’s my best guess anyway.

I planted 3 japanese maples early this spring and 2 out of the 3 died.Because they got more sun then the 3rd. That being said the 2 that died did this and I built a small little shade cloth house for my 3 as it was starting to show the same signs but now that it's in 50% shade cloth it's doing great. Mine are only little saplings so maybe that has to do with why they did this I'm not sure.

 

[Colorado]

It is a fungus, anthracnose

Anthracnose of shade trees

How to identify anthracnose

extension.umn.edu

What are you basing that on?

You maybe correct, but I don’t think you can definitively make this diagnosis from the information provided. I thought this was anthracnose for awhile too but the signs and symptoms - even in the link you posted - don’t add up.

As stated in the link, anthracnose is more common during cool wet springs.

I think there are other causes that can mimic the appearance of anthracnose.

I am not trying to argue with you - genuinely interested in what makes you so sure it’s a fungal infection.

 

[penumbra]

It is a fungus, anthracnose

Anthracnose of shade trees

How to identify anthracnose

extension.umn.edu

I can see why you think it is anthracnose, but I have not seen this fungus as an issue in the summer. As the staff horticulturist for a large firm years back, I saw a lot of this, particularly on London Plane trees, during cool damp spring seasons. Spotting and browning of leaves is common on JM in summer. The curled leaves looks like it may be a deficiency.
I'm not saying you don't have anthracnose, but considering the heat and time of year, I consider it unlikely. You really should have a trained nurseryman or a plant pathologist look at it.

 

[Mellow Mullet]

The damage is done in the spring. These are the same leaves that were infected in the Spring that are on the tree in the Summer. Several applications of Daconil before and after bud break in the spring will knock this out.

 

[yashu]

this happens to my Kashima like clockwork this time of year and the tree was treated post bud break with Daconil and Infuse so at this point I side with those suggesting an environmental factor such as heat/sun/wind. My other maples have not had this issue.

 

[Rivian]

My red seedlings had it all year but it got better since a couple weeks. Im not sure why. The exposure has not changed much at all. I think I fertilized with flower fert that has trace minerals at some point.

 

[penumbra]

The damage is done in the spring. These are the same leaves that were infected in the Spring that are on the tree in the Summer

Well I guess we are waiting for the op at this point. Did it have damaged leaves in the spring? The tone of the post indicates it is more recent.