My dad's Japanese Maple gets these spots on the leaves then the edges dry and curl. It seems like it might be predominantly on one large limb, but I would have to see it later in the summer to be sure. It has been doing this for many years now without any real die-back of the affected limbs, just unsightly foliage as the summer heats up. The tree has been in the ground for I would guess around 8 years or so and otherwise seems fine. Any help would be great. Thanks
A closeup of the leaf spot.
Could you tell us how it is sited and what the light conditions are and how much it gets watered?
It looks chlorotic and sunburned.
I can have him add more organic matter, but the ph is good according to my tester. I'll have him borrow it again this week to double check. It is in the former under story of a white pine of their neighbor, which probably helped acidify the soil to some degree that was topped prior to the maple being planted. It gets pretty much filtered southern sun due to this pine, with some western sun later in the day I would guess. I don't think that it should be getting sunburn in its location, except that it is near the driveway. Maybe the heat from the pavement or the reflected sun (concrete) is causing this, but that dogwood and the maple shade the driveway from the southern sun.
I can't really comment on their watering, but I know that they do water it and most likely deep soakings vs. sprinkling with a hose, especially during last year's drought and during the average summer in an effort to prevent the wilting of the leaves which has been occurring for years. He has tried adding iron (don't know what form) a few years ago and that didn't seem to help.
From what we can see in the photo, you seem to be getting good spring growth that then fries in the western sun once the weather warms up. I suspect some combination of soil and sun exposure (including the driveway reflecting heat). Perhaps those factors are complicated by a poor root system that came out of a container and might not have been transplanted properly. Did you plant it for him, or see how it was planted? Was it container grown, and if so, was most of the potting mix washed away and the roots spread? And was it planted at the right depth?
Guy S.
All good questions. I wasn't there for its planting, but will ask these questions. I am tending towards the reflected heat & sun of the driveway since the damage seems to be on this side of the tree. I think it was bought from a local nursery here and was a decent size, so probably balled & burlapped. I never checked the planting depth. It seems to you guys that it isn't a pathogen issue, more of a culture issue then. Any way to mitigate the reflected light & heat issue besides wetting the concrete all summer?
Here in our area, we deal with a lot of sun problems. I believe it is sunscald. They really are an understory tree, especially in our area.
That looks like typical leaf scorch to me.
The only other thing that would "burn" is over-fertilization - that I can think of that is.
Same as what the others are saying.
Dax
I believe that the problem is due to fire blight, caused by a bacteria. A number of the Japanese Maples are susceptible to this disease.
