Pruning a Lilac Tree - Ask Extension
Hello, I am writing to request some direction on pruning my lilac tree. I planted this tree in May 2022 - 1 year ago. It is now flowering which I am...
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Pruning a Lilac Tree #829014
Asked May 08, 2023, 3:43 PM EDT
Hello, I am writing to request some direction on pruning my lilac tree. I planted this tree in May 2022 - 1 year ago. It is now flowering which I am thrilled about, however, there is a tall, thick center branch that has no buds on it. I would like the tree to grow UP, rather than out like a bush. I am wondering why the thickest center piece, is thickest and tallest, but has no buds. All the flowering branches are low and thin. How should I prune for maximum bloom AND Height? Should I take that thick center piece out as maybe it is more of a "sucker"? or should I thin out the lower branches?
Thank you so much for your help and time! Kindly, Brenda Gluszek
Multnomah County Oregon
Expert Response
Thank you for your question, Brenda. Here is a good article about pruning lilacs that should help: https://extension.oregonstate.edu/news/prune-lilacs-soon-after-bloom
The reasons that some shrubs grow a "leader", like trees, are found in botany, often due to pruning begun in the nursery. But, as the article suggests, you can even it out over 3 years. Here is another resource on pruning techniques: https://extension.oregonstate.edu/sites/default/files/documents/12281/pruningtreesshrubs.pdf
Good luck!
The reasons that some shrubs grow a "leader", like trees, are found in botany, often due to pruning begun in the nursery. But, as the article suggests, you can even it out over 3 years. Here is another resource on pruning techniques: https://extension.oregonstate.edu/sites/default/files/documents/12281/pruningtreesshrubs.pdf
Good luck!
Thank you for the above information. The first article says to prune right after the bloom. I was under the impression, or thought I had read, that one should wait 3 years before pruning, and that would include pruning of the old blooms. Your thoughts on this?
I am uncertain as to the origin of your information, butI can provide no better advice than Professor Penhallegon, quoted in the first article. "...[T]hey need to be pruned, fertilized and shaped almost every year, soon after they are done blooming in the late spring." "The first spring, remove about one-third of the old canes all the way down to the ground." "Over the next couple of years, take out the remaining two thirds of the old stems." "Once you have your lilac looking good, Penhallegon recommends that each year you clip off the faded flowers to stimulate new growth and more blooms next year." He's the expert!
