Japanese Maple

(Question)

Our 12 yr old Japanese maple appears to be slowly dying. It did not bloom as normal and the leaves are curling. The past few weeks it began to grow new shoots. Red colour in picture. Please can you help.

(Answer)

It’s not clear why your tree would be healthy for nearly 12 years then become ill this year.  Wind burn, a common cause of leaf scorch, where leaves turn brown and curl, would likely have shown up before now.  Similarly, we’ve not had the hottest of summers, although the periods between rainfalls has been pretty hot and dry, so your tree may be begging for water.

We have had a number of questions about curling Japanese maple leaves.  The following may be helpful:

  • Brown curling leaves on Japanese maple  this includes a link to our Toronto Master Gardeners Guide Growing Japanese Maples, which provides lots of information on how to care for these trees and what can afflict them. Consider amending your soil with organic matter, ensuring a consistent supply of water (the soil around the tree should not be allowed to dry out)
  • Another possibility is that the tree has a fungal disease called verticillium wilt, which will eventually kill it. See Japanese maple . Other pests like aphids or spider mites could be the culprits. Less likely possibilities are anthracnose or leaf scorch.  Examine the leaves carefully to see if you have insects.
  • SF Gate’s Verticillium wilt on Japanese maple  provides additional information.

I suggest that you contact an arborist for a final diagnosis.  If you don’t know of one, check out Landscape Ontario  for a list of arborists in your area.