Deformed leaves and new growth turning black

[eeeealmo]

I have a relatively young Acer P. that I've been working on, but over the past month or so, I've noticed some troubling developments. As the title suggests, newer leaves look deformed, and new growth that is coming out is turning black. Has anyone experienced this before?

 

[Meh]

Looks like anthracnose to me, but hopefully others will chime in. Anthracnose is treatable with fungicide, and there are lots of very helpful threads on this site about it.

 

[Housguy]

Is it in direct sun a lot? If not Anthracnose, may be a little burnt.

 

[eeeealmo]

Looks like anthracnose to me, but hopefully others will chime in. Anthracnose is treatable with fungicide, and there are lots of very helpful threads on this site about it.

Thanks for the quick reply! When i google anthracnose on maple leaves, the images that come up don't actually look like what I'm seeing at the moment, but maybe it varries. Will be interested to see what others say.

 

[eeeealmo]

Is it in direct sun a lot? If not Anthracnose, may be a little burnt.

Probably from 9-11:30/12. It has been hot recently too.

 

[atlarsenal]

Looks to me it’s on the young tender leaves. I say sun burnt.

 

[0soyoung]

Looks to me it’s on the young tender leaves. I say sun burnt.

I agree.
This happens to my trees when I let them get a touch too dry before watering. Drying breezes can also cause it. If it is a problem, move the tree to a more protected/shaded location.

 

[Bonsai Nut]

Looks to me it’s on the young tender leaves. I say sun burnt.

I agree. Looks like you are having a maple BBQ... and no one told the maple

At this time of the summer in San Jose you probably should have all of your maples under shade cloth.

 

[imhar5h]

I have something similar happening to new shoots on my maple as well. I don't think it is sun burnt because temperatures haven't been that high in my area. I googled anthrocnose in maples, and the pictures show a lot of leaves with brown patches. Doesn't look like deformed leaves.

What could this be?

 

[eeeealmo]

I have something similar happening to new shoots on my maple as well. I don't think it is sun burnt because temperatures haven't been that high in my area. I googled anthrocnose in maples, and the pictures show a lot of leaves with brown patches. Doesn't look like deformed leaves.

What could this be?
View attachment 254070
View attachment 254071

yea that is definitely what a lot of mine look like!

 

[Deleted member 21616]

-- i am inclined to agree with @Housguy @0soyoung and @Bonsai Nut

the implication would be that you are having two independent/isolated issues:

1) black new growth, cause by heat vel sim

2) deformed leaves, unknown cause

-- however, these might be related issues with the same cause:

my kashimas and deshojos develop deformed leaves and their new growth can be black when i go hard on the biogold fertilizer (by constrast, my arakawas and katsuras can handle all the biogold in the world)

@eeeealmo and @imhar5h are you guys fertilizing strongly?

for your consideration:

fertilizer burn on young maple?

I bought several newly grafted Japanese maples in 3-4" pots this spring and transplanted them into 1-gallon containers with good potting soil...

forums.botanicalgarden.ubc.ca

Over Fertilizating a tree

I accidently overfertilized a new magnolia tree that was planted this spring. I used fertilization spikes. I used 5 and should only have used 2 at...

forums.botanicalgarden.ubc.ca

Coral Bark Leaf Verigation and Deformation

Having read all the posts and looked at all the pictures concerning the "Sango Kaku" I have a question. Does anyone have leaves that look similar...

forums.botanicalgarden.ubc.ca

if what these guys (esp. dawgie in both of his posts in the second link) are describing sounds familiar to your situation, search that forum for many similar discussions

if fertilization is not an issue for you, then at least you can rule it out as a possible cause

 

[0soyoung]

I have something similar happening to new shoots on my maple as well. I don't think it is sun burnt because temperatures haven't been that high in my area. I googled anthrocnose in maples, and the pictures show a lot of leaves with brown patches. Doesn't look like deformed leaves.

What could this be?
View attachment 254070
View attachment 254071

I have an a.shirasawanum that looked this same way about a month ago. The nascent leaves looked like they were stuck together because of something like a small caterpillar inside, say. But, gentle inspection didn't reveal anything. The leaves have now emerged and some have strange shapes, like they were half eaten. Subsequent growth is normal, yet these particular leaves remain somewhat lighter green. As all this was happening, I thought 'maybe too much water' and reduced my watering. I really don't know if this is the answer, but the new growth of the last few weeks on the same stems has been normal.

At any rate, it is temporary and doesn't seem to be serious, nor a persistent condition on a shoot. These affected leaves could always be removed and would likely be replaced were they an important part of a bonsai canopy. As a sacrificial shoot, meh.

 

[imhar5h]

@eeeealmo and @imhar5h are you guys fertilizing strongly?

Good information, thank you for that! I have been fertilizing it with 20-20-20 liquid fertilizer every other week in very small doses. I will refrain from fertilizing this maple for the next few weeks and see what happens.

 

[eeeealmo]

-- i am inclined to agree with @Housguy @0soyoung and @Bonsai Nut

the implication would be that you are having two independent/isolated issues:

1) black new growth, cause by heat vel sim

2) deformed leaves, unknown cause

-- however, these might be related issues with the same cause:

my kashimas and deshojos develop deformed leaves and their new growth can be black when i go hard on the biogold fertilizer (by constrast, my arakawas and katsuras can handle all the biogold in the world)

@eeeealmo and @imhar5h are you guys fertilizing strongly?

for your consideration:

fertilizer burn on young maple?

I bought several newly grafted Japanese maples in 3-4" pots this spring and transplanted them into 1-gallon containers with good potting soil...

forums.botanicalgarden.ubc.ca

Over Fertilizating a tree

I accidently overfertilized a new magnolia tree that was planted this spring. I used fertilization spikes. I used 5 and should only have used 2 at...

forums.botanicalgarden.ubc.ca

Coral Bark Leaf Verigation and Deformation

Having read all the posts and looked at all the pictures concerning the "Sango Kaku" I have a question. Does anyone have leaves that look similar...

forums.botanicalgarden.ubc.ca

if what these guys (esp. dawgie in both of his posts in the second link) are describing sounds familiar to your situation, search that forum for many similar discussions

if fertilization is not an issue for you, then at least you can rule it out as a possible cause

To echo everyone else, thank you! This might be the culprit. I will put them in a shadier area and pull back on the fertilizer to see what happens. Thanks again.

 

[rodeolthr]

What is the ph of your water? California (especially southern) has incredibly hard water, which maples tend to dislike, especially acer palmatum. Do you do anything to mitigate it? It could be lending to some of the issues you're seeing. Also, even here in the PNW, the summer growth on my maples is often mangled. I don't pay any attention to it...….jus try to get the growth to extend as much as possible to help thicken trunks

 

[imhar5h]

What is the ph of your water? California (especially southern) has incredibly hard water, which maples tend to dislike, especially acer palmatum. Do you do anything to mitigate it? It could be lending to some of the issues you're seeing. Also, even here in the PNW, the summer growth on my maples is often mangled. I don't pay any attention to it...….jus try to get the growth to extend as much as possible to help thicken trunks

Interesting point, I had not thought about that. Right now it is the water that comes out of the tap. I am waiting for my other deshojo to throw some new shoots so lets see if the same thing happens it could be water related.

 

[eeeealmo]

What is the ph of your water? California (especially southern) has incredibly hard water, which maples tend to dislike, especially acer palmatum. Do you do anything to mitigate it? It could be lending to some of the issues you're seeing. Also, even here in the PNW, the summer growth on my maples is often mangled. I don't pay any attention to it...….jus try to get the growth to extend as much as possible to help thicken trunks

Yea our water in San Jose is garbage. I use rain water as long as I can, but it ran out last month.

That being said, I have an older maple that is doing wonderfully using the same water so I'll put water quality lower on the list for now.

 

[ChristianDGreat]

What are the telling sign for maple if the water ph is the problem?

 

[0soyoung]

What are the telling sign for maple if the water ph is the problem?

chlorisis

 

[Forsoothe!]

Ya know, at least traces of calcium are very necessary for normal plant growth and rain water doesn't have that. Tap water can taste bad to humans and still be perfectly OK for plants that actually like dissolved minerals. And midday sun in San Jose in July is a bad joke for any JM. A bigger pot, with an organic media, tap water, in bright shade, out of high winds, AKA back to basics would probably eliminate a lot of potential culprits and make it easier to isolate the real problem. Occam's razor rules.