Magnolia scale problem


I have a saucer magnolia with a serious magnolia scale problem growing on my property. In each of the last couple of years there has been a paper wasp nest that I have seen up in a different tree situated on my property. Each year, I have been stung by a wasp when I got in close proximity of the magnolia tree. The Arborist I contacted late last fall suggested he could cut down the magnolia tree or I can have the tree treated, but he appeared hesitant about treating the tree. Am I contacting the right “Professional” if I prefer to have the tree treated? In other words is an “Arborist”, the Professional best suited to treat infestations, or is it another type of “Professional”. Any suggestions would be appreciated.
Thank you,



Thank you for contacting Toronto Master Gardeners.

Magnolia scale has become a problem here in Ontario.

The Ministry of Agriculture, Food and Rural Affairs for Ontario is tracking this pest and says the following to help diagnose the problem:

“Magnolia scales are one of the largest scales in North America. Its primary hosts are Magnolia acuminata (cucumber tree), M. soulangiana (saucer), and M. stellata (star). The mature female is about 12.5 mm long, oval convex, smooth, dark brown and covered with a waxy bloom. It overwinters as a nymph on one and two-year-old shoots and the crawlers emerge in late August and September. There is only one generation per year. Honeydew and sooty mould on the branches and leaves indicate presence of magnolia scale.”

You are correct a certified arborist is the best person to asses the damage that is done to your tree and suggest what options are open to you to save the tree. As you were not satisfied with your last consult you may want to contact a different arborist.

For the wasp nest, if it is once again a problem this year, you may want to call an exterminator in your area for removal. That will certainly make it easier to then concentrate on the Magnolia.

The following sites are a good place to look up arborists in your area and will give you their certification and standing. I hope you can find someone who will help you solve this problem. I have also included a link to one of our articles on Magnolia scale. Good luck.

control of magnolia scale