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When and how to trim this locust tree? #909290

Asked July 10, 2025, 3:08 PM EDT

Hello Dear Master Gardener, How and when is the best time to trim this locust tree? We planted it 5 years ago and it is growing very well. Can you give us some advice? Also, will it need any particular treatment down the road, like how we treat our Mountain Ash trees and our elm tree. Also, we planted it too close to our huge elm tree, so now the tree wants to "bend" the opposite direction of the elm. It's because we thought we were going to lose our elm tree to disease, but it's doing very well. Can we use a rope system to gently pull it so that it will stand up straight? Located in the twin Cities

Hennepin County Minnesota

Expert Response

Hello Dianne, 

Thanks for reaching out! It's best to trim locust trees in the late winter, when they are dormant. This will help you avoid stem cankers, and the wounds will seal with new growth: https://extension.umn.edu/planting-and-growing-guides/pruning-trees-and-shrubs#time-pruning-to-avoid-diseases-and-other-problems-1336760

You shouldn't need to treat the tree unless you see issues (dying leaves, insect damage, etc.). It looks healthy in the photos you sent, so you should be set unless issues crop up in the future. If so, you are welcome to submit a question again, and we can take a look! 

Finally, I'd caution against any rope system for the tree. The trunk is fragile, and pruning it next winter might be enough to help it even out a bit. Trying to alter the direction of an adult tree (i.e., through staking or by using rope) is generally not recommended. 

I hope this helps!

An Ask Extension Expert Replied July 10, 2025, 7:47 PM EDT

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