Using Sugar to Control Dollarweed: Mechanism and Tree Safety

Granulated sugar can suppress dollarweed by rapidly reducing soil nitrate levels (research from Charles Sturt University). Apply 1 lb per 250–300 sq ft, water in same day to avoid ants. Repeat spring and fall.

Sugar neutralizes nitrate. It likely won't harm established tree roots, but avoid applying inside the tree's drip line as a precaution.

— Mack Jean, Master Gardener, Tennessee