Strange Discoloration on Japanese Maple 'Kinran'

[eeeealmo]

Hi Everyone! This year, after a healthy flush of growth and diligent pinching, my Kinran maple is showing some very unusual discoloration on some of the leaves, and I'm curious if anyone has seen anything like this before. It almost looks as though the leaves were burned or damaged, but I have not sprayed it with anything, nor do I overhead-water. I'm worried it is spreading, and would like to be proactive if there is something I can do.

The only thing I can think of is that I might have been too rough while pinching new buds, and somehow damaged leaves causing them to be susceptible to sun-burn - is this a possibility?

Any input would be greatly appreciated. Thanks everyone!







A glamour shot to make myself feel better about the situation

 

[clem]

Nice tree !
it could be sun burn although usually/logicaly the leaves burnt are the upper leaves and not the leaves inside the tree. If it was my tree, i would remove the damaged leaves (partial cut of the leaves or total cut if the leave is totally damaged) to check if other leaves are damaged in the future or if the process is finished.

 

[Velodog2]

Oh my what a nice tree! Never seen that cultivar as bonsai. That trunk line and root flare are extraordinary! Not sure about the upper part. Wouldn’t mind seeing a pic without leaves.

 

[0soyoung]

It is indeed a very nice tree!

Regarding the problem, I think you should do as @clem and I have done when looking at your pix. There is seemingly a pattern to the occurrences, yet there isn't. I've also tried to imagine how I might have 'splashed' something on the leaves when they were first emerging or when I was ... --> have you thought back to when this might have happened and etc???

Then I think, it doesn't seem to be spreading (right?), so it is likely just cosmetic at this point. I would make a 'note to self' and simply remove those leaves, get my favorite beverage and enjoy the eye candy! It is beautiful.

 

[Wires_Guy_wires]

it could be sun burn although usually/logicaly the leaves burnt are the upper leaves and not the leaves inside the tree.

Agreed, but if you have a close look at people's gardens, you'll find there's usually a bunch of reflective stuff hanging and dangling around.
One sun + the reflection of that same sun, focused on one spot will burn the foliage off of any plant.

We used to have a mirror with a nice angled edge hanging around. A couple weeks a year it would project a huge rainbow on the wall between 11:00 and 11:30. The rest of the year, it didn't. The point I'm trying to make is that we'd expect streaks to form, due to the movement of the sun and our planet. But sun spots can be pretty localized depending on season, angle, wind (if it's a chime reflecting, or some kind of metal plant tag) and so on.

Chlorine cleaner can have the same effect, as do many types of lye, hydroxides and acids.

 

[eeeealmo]

Thanks for the input everyone. I will try and remove all the damaged parts and keep an eye on it to see if more of this discoloration shows up.

As requested, here is the tree earlier this year without leaves. It still needs a lot of work, and has some issues that are slowly being addressed, but otherwise a very fun and unique tree i am glad to be taking care of.

 

[Forsoothe!]

The damage looks like chemical damage. Droplets accidental slung on them while the leaves were just unfolding.

 

[HorseloverFat]

Cold, Wisconsin Spring wind-stress on My New, Texas-grown JM arrival produced pale, discolored spots on leaves, similar to that.. Yours DOES look more deliberate, though.. as has been stated above.. hmmmm

 

[eeeealmo]

The damage looks like chemical damage. Droplets accidental slung on them while the leaves were just unfolding.

It is awfully close to my neighbors fence & plants - I am wondering if something made it over from their yard. I've removed all the damaged areas and moved the tree to a different spot just in case.

 

[clem]

I'd like to add a comment on your tree : on the 3rd pic, the leave you have in your fingers look smaller than the leaves on the upper branche, right ? If yes, this mean that the small secondary branch under the leaves is weaker than the branches that recieve more sunlight. If you do nothing, with time, the difference of strength will get more and more visible, and maybe the small branches inside your tree will die. A solution is a partial cut of the big leaves on the upper branches of your tree (to let the sun enter inside the tree and to lower the photosyntesis of the big leaves) : you can cut for example all the leaflets and let the central one

 

[penumbra]

The damage looks like chemical damage. Droplets accidental slung on them while the leaves were just unfolding.

My thought as well.

 

[eeeealmo]

Tree ended up being fine all year. My only guess was my neighbor happened to splash something on it. Anyway here is an updated picture with its amazing fall colors.