Eradicating Bentgrass and Preventing Reinvasion from Neighbors

Why Mowing Low Fails

Bentgrass (Agrostis) grows denser when mowed short – that’s why it’s used on golf greens. Scalping won’t eliminate it.

Effective Removal

1. Glyphosate (Roundup) application: Spray in late April on a calm day. Avoid contact with desirable grass, shrubs, flowers. Do not mow 3 days before or after.
2. Wait 7–10 days for complete kill.
3. Remove dead sod, loosen top 1–2 inches of soil, rake smooth.
4. Apply starter fertilizer (high phosphorus).
5. Sod or hydroseed. Sod works well in spring; hydroseed is better in late summer/early fall.

No need to import topsoil – clay is fine once loosened. Roll new sod with a landscape roller for good contact.

Partial vs. Full Renovation

With 25% bentgrass (one large patch + smaller spots), replace only the affected areas. Full renovation is unnecessary expense.

Neighbor Barrier

1. Dig a 6‑inch wide V‑shaped trench along the property line (vertical side toward neighbor, 45° slope toward your lawn).
2. Fill with loose mulch (straw, leaves).
3. Monthly, chop down the vertical face with a shovel to sever invading stolons.
4. Inspect regularly for escapees.

This physical barrier plus vigilance keeps bentgrass from creeping back.