When to Mow a Newly Seeded Lawn

The 1/3 Rule & Height Guidelines

At 4 weeks post-seeding with grass ~1 inch tall, wait until blades reach 3–3.5 inches before first mow. Never remove more than 1/3 of blade height at once.

First Mow Steps

1. Ensure soil is firm (not soggy) to avoid rutting.
2. Set mower to highest setting (3+ inches).
3. Use a walk-behind mower if possible—riding mowers tear tender roots.
4. If using rider, turn slowly, avoid sharp pivots.

Critical Preconditions

• Starter fertilizer applied at seeding.
• Consistent moisture maintained since germination.
• Grass well-rooted (tug test: resists gentle pull).

Ongoing Mowing

Mow frequently at 2.5–3.5 inches. High mowing encourages deep roots, shades out weeds, reduces stress.