Can anyone tell me what is wrong with our newly planted Japanese Maple (acer pulmatum nigrum)? It was planted in mid-spring as directed, receives proper sunlight, and is regularly watered. The maple has lost practically all of its dark red color (leaves are now mainly green) and some of the leaves look like they are dying. However, there is always new growth. Have the roots just not taken hold, does it need spraying for aphids, more water, or some kind of vitamins added? Any help would be greatly appreciated. (Our zone is central Indiana) THANKS!

Reply to post by Diane H, on July 30, 2002 at 22:37:33:

Identifying the tree is very important.
Acer nigrum is the 'Black Maple'
I also found listings for two Japanese maples with the word nirum in them:
Acer palmatum 'Nigrum'
Acer palmatum 'Dissectum Nigrum'

Perhaps someone else who knows this particular tree can say whether the red leaf color is normally replaced with green in the summer. Color change might not have anything to do with whatever is killing some leaves.

If your tree is truly a Japanese maple, it may have become heat stressed or sunburned. That typically happens to open-grown trees in northern interior California.
Many of the A.palmatum varieties are very susceptible to that, so sun exposure must be carefully planned.
I wouldn't spray for anything you don't see and understand.
It sounds like you need to find a good local certified arborist to give you an onsite evaluation.
While you are at it, make sure that the tree wasn't planted deeper in the ground than it was in the container.

Keeping the root area cool with mulch can be important during extreme heat. Let us know what happens.

Reply to post by Mark Goodwin, on July 30, 2002 at 22:37:33:

http://www.na.fs.fed.us/spfo/pubs/silvics_manual/table_of_contents.htm

This link will take you to a site where you can find detailed info on Black Maple, if it turns out that is what you have.