Pruning an Olive Tree

Credit: Flickr / byrdiegyrl

Q: How and when should I prune my olive trees?

The ideal time to prune an olive tree is in the spring. Winter is too early for pruning because making cuts allows entry points for diseases to spread through rainwater, and winter may be especially rainy. Also, thinning a tree’s canopy during cold weather makes it more vulnerable to frost damage. Summer may be too late if the tree is already in full bloom because pruning will remove tissues towards which nutrients and carbon reserves have already gathered, resulting in a loss for the plant. Additionally, olive trees should not be pruned until they are at least four years old so they can experience maximum growth in their early years.

Once it is time to prune, aim to first open the tree’s centre. With loppers and a pruning saw (and a pair of gloves and goggles), make a few well-placed cuts to remove large branches on the interior of the tree. Leave a small stub of the branch to avoid injuring the tree’s trunk. It is best to start at the top of the tree and work downwards. This may have to be continued over several years to “train” the tree to stop forming large inner branches. Opening the tree’s interior allows more light inside the canopy.

After the tree has a relatively open centre, most pruning will consist of thinning cuts to remove any growth starting to encroach on the tree’s interior, but not eliminating whole branches. This can be done with pruning shears. In the tree’s mature years, pruning cuts are mainly intended to renew the fruiting capacity of the tree to ensure the highest yields and to contain the size of the tree. When in doubt, less pruning is better—an olive tree doesn’t necessarily need to be pruned every year.