Japanese Maple


We have a 30 year old Japanese Maple which is 30ft high. For the last few years we have had bad spider mite which we have treated with Diatomaceous Earth (puffed over the lower branches and placed on the crooks where branches join the trunk) and we have also sprayed with End-all. One branch has died and half appears to have had the bark eaten off. Should be cut the dead branch back to the trunk or just to the point where it has not been stripped. At what time of year should we do this?
We live in Rosedale Toronto, clay soil, tree gets sun & shade. The tree does not seems to be very happy. Your wisdom will be greatly appreciated.


Thank you for reaching out to Toronto Master Gardeners.  Sorry to hear your Japanese Maple is not doing well.

With your tree being 30 years old, having branch die back and bark loss, I would recommend you get an arborist to have a look at it.  They will be able to rule out any disease or infestation issues and provide you with pruning and overall plant health advice, as well as treatment if it is warranted.  As this is an older tree, care going forward is very important so that you don’t lose it, as it would be expensive to replace.

If you don’t already use the services of a certified arborist, you can find one at Landscape Ontario (see link), select Arborist in the I’m Looking For and put in your location to get a list of Arborists in your vicinity that would be able to assist you.

Hoping all is well with your Japanese Maple.