Apply a balanced starter fertilizer when overseeding

What to Do

When seeding bare patches or overseeding in spring, use a starter fertilizer with higher phosphorus (e.g., 10-18-10 or similar) applied at the time of seeding.

Why It Works

Phosphorus promotes root development in new seedlings, giving them the best chance of establishing before summer heat arrives. Mature lawns rarely need extra phosphorus, but new seed benefits significantly from it in the first 4-6 weeks.

Tips

• Check your soil test before applying phosphorus — many soils already have adequate levels.
• Several states restrict phosphorus use on lawns. Starter fertilizer for new seedings is typically an allowed exception.
• Do not use starter fertilizer on established turf that is not being seeded.