Do I need to cut one of these lilac trunks? They are crossing and rubbing, but I’d prefer not to cut one down.
Thank you for contacting the Toronto Master Gardeners with you Lilac question.
It is advisable to prune lilacs every year in order to develop an open strong framework and vigorous growth. Start by removing any dead, diseased stems as well as any crossing over branches which are causing damage on neighbouring branches. From your photo the branch to the right appears to have an open wound near the top of the photo and should be cut to the ground. An excellent article on Fine Gradening- Pruning Lilacs states: “Yearly pruning consists of cutting diseased, misshapen, and unproductive stems to the ground.” Allowing a few inches between each stem will avoid overcrowding, allow light and air to enter which will lead to a healthy vigourous shrub.
Good Luck with your Lilac