Aspen Trees in Portland

Asked May 20, 2017, 7:43 PM EDT

The former owner of our home planted 3 aspen trees on a flat garden area without grass. We love them and over the last 5 years done mostly well. They have grown a little out of control while we were away for 1 1/2 years, and they need to be pruned - we plan do to ourselves. Can we prune them now that they are completely leafed out - or do we have to wait until next winter? Although we know not recommended, the top of one of the trees really needs be pruned as it is pulling the rest over when windy. And one has tons of small "branches" very low. Thanks so much!

Multnomah County Oregon

3 Responses

Thanks for your aspen pruning questions. Here is a link to a very thorough article about aspen trees and their management. It's unclear from your question how old the trees actually are, but the article covers both young and mature trees (and addresses timing and topping.)

Although you didn't ask this question, and it's ambiguous from the photos, just want to alert you to the tree pruning permit requirement if your trees are in the City of Portland right-of-way. I only know you're in Multnomah County, and not whether you're in Portland. Here's the link.

I hope you find these helpful. Good luck!

Thank you for the link - it is somewhat helpful. I cannot find a definite answer about pruning the single branch at the top - because I do not believe that it's truly "topping" the tree (please correct me if i'm wrong).
The trees are about 7 years old and away from our private road.

Thanks very much.

One branch's pruning doesn't count as topping, so don't worry about lopping it off. However, since it appears to be an apical branch (think 'top' or 'apex' or dominant), expect lower branches to grow to take its place as they become co-dominant. They will not grow straight up, but out to the sides. Nature marches on!