Tree Disease Diagnosis & Treatment in Lansing, MI

The Lansing area's two big ones

Emerald ash borer has worked through most of Ingham and Eaton County's ash canopy. Signs: crown thinning from the top, D-shaped exit holes about an eighth of an inch across, S-shaped larval galleries under peeling bark, woodpecker damage, and sprouts from the trunk base. An ash that has lost less than a third of its canopy is often worth treating with a trunk-injected systemic insecticide every two years. An ash further gone than that is a removal, and it gets more expensive to remove every year it stands dead. Full guide: EAB in Michigan.

Oak wilt kills a red oak in weeks to a single season. It spreads by beetle to fresh wounds between April and July, and underground through root grafts between neighboring oaks. Once a red oak shows symptoms it is generally lost. What can be done is protecting the oaks around it: severing root grafts with a vibratory plow before removal, and preventive propiconazole injection on high-value healthy oaks in the spread zone. Full guide: oak wilt in Michigan.

Problems that look like disease and are not

A lot of what gets called disease in Lansing yards is something else. Anthracnose after a wet spring makes irregular brown blotches along leaf veins on maples, oaks, and sycamores; it looks terrible and is rarely fatal. Scorch from drought or root damage mimics wilt but starts at leaf edges and hits the whole canopy evenly. Construction damage, especially trenching and regrading over roots, produces decline five to fifteen years later that homeowners read as disease.

The tell for the serious pathogens is speed and pattern. Oak wilt is fast and top-down. EAB is slow and top-down with the exit holes. Slow, patchy, bottom-up decline is usually stress, not infection.

What treatment we do and do not offer

We diagnose on site, we treat what treatment actually helps, and we say so when it does not. Trunk injection for EAB on ash worth saving. Preventive injection for oaks in an active oak wilt zone. Root graft severing before an infected oak comes out. Correct disposal of infected wood so it does not seed the next outbreak. Pruning to remove diseased material where that helps, timed by species.

What we will not do is sell a treatment program for a tree that is past saving, or spray for a problem that is really compaction or drought. Laboratory confirmation for oak wilt is available through MSU diagnostic services and we will point you there when it matters. Sometimes the right answer is a removal, and we tell you that on the first visit rather than after two seasons of injections.

Timing

EAB treatment goes in during the growing season, generally late spring into summer, and repeats on a two-year cycle. Oak preventive injection is done in spring before the beetle window. Oak pruning and removal happen November through March. Diseased-wood pruning on other species is timed to the species' dormant window. If a storm opens a wound on an oak in June, cover it the same day.

Tree Disease Treatment questions from Lansing homeowners