Most Michigan homeowners prune at the wrong time of year. Here's the certified-arborist calendar we follow across Greater Lansing — and the species that break the rule.
Timing is the single biggest factor that decides whether a pruning cut helps your tree or hurts it. Cut at the wrong moment and you invite disease, sap loss, or stress that the tree may never fully recover from. Cut at the right moment and the same wound seals cleanly within a single season.
For most deciduous trees in Mid-Michigan — maples, ashes, lindens, honey locusts, and the like — the best window is late winter through very early spring, roughly mid-February to late March, while the tree is still dormant. The structure of the canopy is fully visible without leaves, decay fungi are inactive, and the tree's spring growth flush will quickly compartmentalize the cut.
Oaks are the major exception. To avoid oak wilt, never prune an oak between April 15 and July 15 in Michigan. The sap beetles that spread the disease are most active in that window, and a fresh cut is an open invitation. Schedule oak work for the dormant season whenever possible, and only handle emergency oak removals with proper wound dressing during the high-risk months.
Spring-flowering trees — flowering cherries, crabapples, magnolias, lilacs — should be pruned immediately after they finish blooming. Prune them in winter and you cut off this year's flower buds before they ever open.
Summer is acceptable for light corrective pruning, deadwood removal, and clearance work, but avoid heavy structural cuts in July and August when trees are under heat stress. Fall is the worst season for most pruning: decay fungi are releasing spores, and the tree has shut down its healing response for the year.
If you're unsure where your tree falls on this calendar, that's exactly the kind of question we answer for free on a site visit. A 15-minute walk-through usually saves homeowners from a year of regrowth they didn't want.
