Q.Our mountain ash has suckers
Our mountain ash has suckers or shoots at the base and we would like to know how to stop these. The tree is 6 feet tall and we brought it with us from our old place in a big pot. How do we prune these off and stop them from coming back? Thanks.
The suckers may be a result of the stress of being transplanted. Cut them off, keep them cut off, give the tree the best care possible, and in a short time it should stop sending the suckers out. Here's some more information you might find helpful. https://www.gardeningknowhow.com/ornamental/trees/tgen/tree-sucker-removal-and-tree-sucker-control.htm
https://www.extension.iastate.edu/forestry/iowa_trees/trees/american_mountain_ash.html