Dead Dogwood By “Mower Disease”

“Mower disease” is a totally preventable human malady caused by permitting lawn grasses and weeds from growing near the crown of trees and shrubs. The problem is commonly seen on large properties such as church grounds, cemeteries and public parks. Large gang mowing machines (with many reels) cut 95-98% of the turf area. Workers follow along with push mowers and string, blade weed-eaters or “weed wackers” around trees and shrubs.

String mowers are blamed for most of the unsightly bark injuries. The tree or shrub is eventually weakened by sap leakage and nutrient loss. The damage also exposes the tree/shrub crown to numerous disease infection and insect borers.

A better management practice is to maintain a thin organic mulch zone around the tree or shrub base. The mulch should never be piled up against the trunk. A mulch layer more than 4 inches is not recommended.

Weeds will eventually grow on surface of decaying mulch barrier. Periodically, hoe or hand-pull invading grasses and weeds atop the mulch. An alternative is to spray a weed herbicide such as Round-up™ or an equivalent product according to label directions. When done, add 1-inch of mulch for a fresh clean appearance.