Mature Manitoba Maple

(Question)

I have an Manitoba maple that is diseased at the base and is 80+ years old I believe. How can I assist the tree, extend its life and /or treat the disease? It is in my backyard, so I understand that I would have to apply for a permit to have it removed at my expense when the time comes. I am trying to determine what a prudent person would do at this point as I enjoy the shade that it provides, even though it is an invasive species. Sigh.

(Answer)

Manitoba maples (Acer negrundo) are susceptible to a variety of insect pests and diseases, and if yours is obviously diseased at its base, this may be the time to call in a professional arborist who can look closely at your tree, diagnose it, and help you to decide on the best course of action.  To locate an arborist in Ontario, please go to the International Society of Arborists’ Ontario website:  https://www.isaontario.com/content/find-certified-arborist.  Manitoba maples are often described as invasive, weedy, messy, shallow-rooted and weak-branched.  At 80-plus years, yours is a very mature specimen of this native maple whose unique leaf shape is quite distinctive.

It would be ideal if your mature tree could be saved, of course, but if you and your arborist determine that your tree has truly reached the end of its days, you will at least have the pleasurable task of choosing a replacement.  You may find Landscape Ontario’s fact sheets on urban trees to be a good starting point: https://landscapeontario.com/trees-for-urban-landscapes  The Toronto Master Gardeners’ guide to tree planting is a also useful resource for the future:  https://www.torontomastergardeners.ca/gardeningguides/planting-a-tree-a-toronto-master-gardeners-guide/

Resources:

https://www.uoguelph.ca/arboretum/thingstosee/trees/manitobamaple.shtml

https://www.ontario.ca/page/manitoba-maple