I planted this Autumn Blaze maple in a tree pit across from my building last September. It seemed to be doing well and dropped its leaves in early November as expected. It leafed out this spring nicely and put on about 4 inches of new growth then the leaves started turning red at the end of May as if winter was coming. See the attached picture. I guess it's been like this about two months now. The leaves are slowly becoming more red as time goes on and it's not putting on new growth nor has it dropped any leaves (yet). It's not planted too deep and we've been getting rain at good intervals so I haven't had to water it much. I'm in NJ, USA (zone 7A, I think). I suppose there's not much I can do but wait it out unless someone here tells me differently. If nothing else I'd like to know why this is happening besides just transplant shock. The ABM I planted in the tree pit next to this one did not do this. Thanks for your help.
Following are a few links to articles on autumn color. Premature autumn color can be due to a number of issues, including an indication of stress to the plant, but I have found no reference to fall color as early as the beginning of June. Both red and silver maple, A. rubrum and A. saccharinum, respectively, are among the trees most prone to this expression, and they are the parents of Acer x freemanii Autumn Blaze. http://www.ulsterpublishing.com/index.cfm?fuseaction=article&articleID=354366 http://theheartofnewengland.com/LifeinNewEngland-Autumn-Leaf-Color.html http://www.dnr.state.mn.us/fid/august97/08259704.html If there seems to be no discoloration of the trunk or branches, no infestation of insects or obvious fungal or bacterial issues with the leaves of the tree in question, I would look to the soil. It sounds as if you are kind enough to be seeing to the upkeep of these trees for your neighbors, while the city provides no care. It is quite possible that the soil conditions the short distance between the two tree pits is different. You could dig a 12-18 hole in each pit, fill them with water, let them drain, then fill them with water once again and time the drainage. You could ask the city to pay for a soil test; good luck. Here is a link on New Jersey soils: http://www.nj.nrcs.usda.gov/technical/soils. Transplant shock should not be an issue at this point. Finally, make sure that these two trees are specimens of the same cultivar; unfortunately, maples are mislabeled all of the time. We would need close-up photographs of the leaves to assist in this regard. Let us know what you learn.
I have a similar situation. My acer Rubrum planted last fall shows brown/red color on a few branches. The leafs are a little wilt. I am going to increase irrigation a see if that helps. Also it may be a good idea to submit a sample to local diagnostic laboratory to see if there is no verticicillium wilt or duch elm disease. Regards Andrzej
I have had a seedling show autumn colour during June and July and drop its leaves two weeks ago. I believe it is due to stress due to a very wet three months here. I think it will be fine next year again
