Good morning, we live in East York (St. Clair and O’connor area) and have a 7-8 year old Japanese Maple in our front yard, western exposure.
We want to prune it’s heigth and are wonder if now (April 7th, 2019) is a good time while it is still dormant, or wait until later in the spring.
Can please advise a good time?
Many thanks in advance and also many thanks for the service you provide.
Thank you for contacting Toronto Master Gardeners.
You mention you want to prune the height of your Japanese Maple. Japanese Maples have an elegant form and as with any tree, if you remove the top you will lose the form of the tree. Shortening a tree can also effect the health of the tree as it loses a large percentage of its canopy. Correct pruning techniques will remove dead branches, crossed branches and open up the crown to air flow. Topping a tree is not recommended.
At this point the trees have started warming up and the sap is running so you are a bit late for this season. If you have dead branches those should certainly be removed. When the tree is dormant in the late winter is the best time to prune.
When pruning, it is important not remove too much of the tree’s branches. It is best to prune over a few years only taking off some branches each year. When cutting off a branch, follow it down to where it attaches to a main branch and cut it there. Cutting back to main branches thins out the crown and allows more air flow and a greater resistance to disease. If you cut only the end of the branches, the buds remaining on that branch will grow in random directions and wreck the natural elegant form of the tree.
If you are unsure about the best pruning for your tree you can consult an arborist for advice. They will come out and look at your tree. You can find certified arborists at Landscape Ontario. https://landscapeontario.com/
I am attaching some links below with further information and diagrams on pruning.