Roughleaf dogwood (Cornus drummondii) grows more as a medium to large multi-stemmed shrub but can be trained into a small tree. If you would like to train it into a small tree with a central trunk/leader then you can remove or cut back one of the competing stems. Choose the smallest or weakest of the two stems and keep the other. If they are equal in size and health then choose the one that seems to be the most straight and upright. For some tips on pruning and training trees and shrubs see our fact sheet Training Young Shade and Ornamental Trees. You can also reach out to the Tulsa County OSU Extension Center for additional assistance if needed.