When to prune trees in Missouri

Most trees: late winter

Pruning while a tree is dormant, roughly December into early March, lets you see the branch structure with the leaves off, and the cuts start closing as soon as spring growth begins.

Maples, birches and a few others drip sap when cut in late winter. It looks alarming but does not hurt the tree.

Oaks: winter only, never mid-March to mid-July

Oak wilt is a fungus that kills oaks, red oaks especially, and small beetles carry it to fresh wounds. University of Missouri Extension says to prune oaks in winter, after the leaves drop, and to avoid any cutting or bark damage from mid-March through mid-July, when the beetles are active.

That includes limb removal, trenching near the roots and construction work around oaks. If an oak is damaged in a spring storm, have the broken limbs cleaned up, but plan any other trimming for winter.

Spring-flowering trees: right after bloom

Redbud, dogwood, serviceberry and crabapple set next year's flower buds in summer. Prune them in winter and you cut off this spring's flowers, so if blooms matter to you, prune soon after they finish.

Any time of year

• Dead branches
• Broken or hanging limbs ("hangers") after a storm
• Branches rubbing a roof, or blocking a sidewalk or street sign

Cuts to avoid

• Topping: cutting the top off a tree or its main limbs. It starves the tree and the regrowth is weak and dangerous. A company that recommends it is a red flag.
• Taking more than about a quarter of the leaves in one year.
• Flush cuts against the trunk. Cut just outside the collar, the swollen ring where the branch meets the trunk.
• Painting or sealing cuts on most trees. A clean cut closes on its own. The exception: MDC advises covering fresh wounds on oaks during the spring oak wilt season.