Thanks Drew. I may need to remove the leaves with these spots. I'm going to rotate hydrogen peroxide and daconil spray weekly. I think the air layer I have on it may be adding stress to the plant.I believe that is fungus given the spots. I treated mine with dormant oil this year twice before bud break and right after and mine has seemed more healthy than ever. Sunburn would start from the edge of the leaf I think
I did a little research. Think you are correct about it being fungus. I caused it by overwintering in leaf mulch. It is very persistent fungus. I sprayed with copper monthly and used phyton 27 (systemic) in beginning of spring. I have better spot for them this year.I believe the brown/tan spots are either Phyllosticta or Cercospora leaf spot, I have spots on my maples this year too.
They're a type of fungus, but apparently don't pose too much of a threat to the overall health of the tree, just make them look a lot worse. I don't have experience with getting rid of it or preventing it, just beginning to do some research into it now.
I did remove some leaves. I believe that as long as they are not actively fruiting (indicated by black dots in the center) the tree is not threatened.Thanks Drew. I may need to remove the leaves with these spots. I'm going to rotate hydrogen peroxide and daconil spray weekly. I think the air layer I have on it may be adding stress to the plant.
sun scald - too much sun
the Acer palmatum cultivar 'Katsura' is famous for getting sun burnt in early spring. It tends to leaf out ahead of our landscape trees, and my experience has been that you really have to be careful the first few weeks of spring, and keep it in the shade. Once the landscape trees have leafed out, you can set it where it gets a little sun. But it really needs shade until after the leaves turn more green.
I've had some good luck with my maples since I started treating them before any fungus problems can seed. Daconel every 2 weeks and an hydrogen peroxide dilution (2tsp/quart) whenever it gets too much rain. Its been raining for a few days so I make sure all my maples get a fine mist of the H2O2 dilution. I'm also using a silica product this year to help with sun damage. Ideally a sun screen would be great especially for katsura or Aurum.Sorry if improperly 'reviving' this thread with a similar question.
Last months I received a weak mame maple / acer katsura, which I should have sent back but I'm trying to recover first. I'm worry about leaves color, View attachment 240919View attachment 240920scorching (it was under might day sun) and at the same time Akadama staying wet for too long. Is it fungus? Any advice?
First photo from last month after delivery and second pic was taken yesterday.