Pruning deciduous trees
(maple, mountain ash, oak, linden, locust, Russian olive, crabapple, etc.)

Formative pruning of young trees
(first 5 years)

• Select one main stem or leader and maintain the natural shape of the tree.
• Make sure that the primary branches are spaced evenly around the trunk, about 30 cm apart. Remove any primary branches that are too large (almost as thick as the trunk) or growing at too sharp an angle to the trunk (less than 60°-although this may vary depending on the species or cultivar).

Maintenance pruning

• Remove any dead or diseased branches.
• Remove any inward-growing or crossing branches.
• Remove any branches near the base of the trunk.
• Evenly space the primary branches.
• Never remove more than 15% of the upper branches in any given year.
• It is usually best to remove any epicormic branches (sprouting vertically from the trunk or primary branches).
• Remove any suckers (growing at the base of the trunk).

When to prune

Formative pruning: when the tree is first planted and in late spring, to make sure that wounds heal quickly. Also when the tree is dormant (fall or early spring).

· Maintenance pruning: year-round, or as needed. Prune birches, maples, lindens, walnuts, willows and poplars in May, for the sap flows too freely in March and April.