Hello to everyone – this is my first posting – hope I’m doing it correctly! I purchased a smoke bush last week (final sale) but the spot I was intending for it doesn’t get as much sun as I thought. Decided on a location where it will only work if it ends up as a tree. There are three main “trunks” that start about 2 inches from the ground and branch outwardly. These have a few smaller shoots. Do I leave the three stronger stems but prune off the others? Just planted it today – about 3 feet tall. Have googled this question but can’t find consistant instructions, or exactly when to start the “surgery”. By the way, I checked the subject list and didn’t see this question there. Hope I’m not repeating. :) Thanks!
You can either leave the three main stems and remove any smaller, or if you prefer a tree with a single trunk, you will need to choose one of the stems to be the main trunk and cut everything else. As the shrub grows taller, begin to remove any lower horizontal branches. Cotinus should be pruned in early spring to avoid removing flower buds. Here is some general info on Cotinus. For more detailed info on pruning for tree form, read the Shaping Tree-Form Shrubs section of this fact sheet from Clemson’s extension website.