Some shrubs have the ability to grow as bushes or to be trained as trees. Magnolias and lilacs are popular shrubs that can be trained to grow as trees. Crape myrtles, viburnums, burning bushes, red and yellow twig dogwoods, and rose of Sharon are some other types of shrubs that will make beautiful ornamental trees if they are trained. Begin training your young shrub or re-shape your more established shrub in the late winter or early spring. This is the best time to prune away the necessary branches.
Select a strong and straight growing stem to be the main stem on your 1-year-old shrub.
Remove all other branches by pruning them as close to the main stem as possible.
Clip the tip off of the main stem to stimulate lateral branch growth at the top of the shrub.
Hammer a stake into the ground as close to the main stem as possible and tie the stem to the stake.
Remove any buds that appear below the top group of buds. Simply pick them off.