By Louis Rinfret
Montreal Botanical Gardens, Horticulture Department

At the Japanese garden of the Montreal Botanical Garden we start pruning when the possibility of severely cold weather has passed. It’s usually by the end of February. We prune while the trees are still dormant. It can be as late as mid April.

Louis pruning at Montreal Botanical Garden. Photo by Mireille Rico

Due to the lack of hardiness of cherry trees like Prunus serrulata and Prunus subhirtella in our northern cold climate, we use crabapples trees as a substitute.

When pruning this type of tree we start by removing suckers and water sprouts. The suckers grow from the rootstock of the tree. If we allow them to develop, they can grow into new trunks, possibly of a completely different tree type. This is because the crabapple was grafted onto the rootstock of a different variety. The removal of suckers can be done at any time of the year.

Blooming Crabapple Tree (last May). Photo by Louis Rinfret.

Water sprouts are small shoots that emerge at an angle between some of the main branches. They don’t usually produce fruit.

The next step in cutting back is to remove any dead branches and increase the space between branches so as to decrease the risk of disease spreading from one branch to another.

Once all of the above is done we proceed to the aesthetic pruning. We remove branches or parts of them to reveal the natural beauty the tree has to offer, making sure that the remaining branches are well-spaced from each other. The spread of disease is more frequent when branches are crowded. We also shorten certain branches in order to control the growth of the tree and to encourage flower buds and eventually fruit.

Besides crabapple trees we do dormant pruning on many other deciduous trees.

*First Picture: Louis pruning at Montreal Botanical Garden. Photo by Mireille Rico.

*Second Picture: Blooming Crabapple Tree (last May). Photo by Louis Rinfret.