Which practice is not an accepted mechanical weed control method?

Which practice is not an accepted mechanical weed control method?

• A. Rototill the garden in early spring before planting
• B. Smother weeds with cardboard topped with mulch
• C. Cut or mow and then re-cut
• D. Remove and bag flowers and seeds and dispose of them in a landfill

Answer: (A)

Mechanical weed control relies on physically suppressing or removing weeds without chemicals. Rototilling the garden in early spring before planting is not considered an accepted approach because deep tillage disrupts soil structure and beneficial soil life, and it tends to bring weed seeds from the soil seed bank up to the surface where they germinate, often increasing the weed problem rather than reducing it. In contrast, smothering weeds with cardboard and mulch blocks light to existing weeds, cutting or mowing reduces weed vigor and limits seed production, and removing and bagging flowers and seeds prevents spread. So while tillage is a physical method, using a rototiller before planting often backfires by promoting more weeds.

Mechanical weed control relies on physically suppressing or removing weeds without chemicals. Rototilling the garden in early spring before planting is not considered an accepted approach because deep tillage disrupts soil structure and beneficial soil life, and it tends to bring weed seeds from the soil seed bank up to the surface where they germinate, often increasing the weed problem rather than reducing it. In contrast, smothering weeds with cardboard and mulch blocks light to existing weeds, cutting or mowing reduces weed vigor and limits seed production, and removing and bagging flowers and seeds prevents spread. So while tillage is a physical method, using a rototiller before planting often backfires by promoting more weeds.