Overseeding a Year-Old Sod Lawn in Kansas City: Timing and Technique

A Kansas City homeowner's one-year-old sod lawn is patchy and needs overseeding. They want suggestions.

Optimal Window

Aug 15 – Sept 1 for cool-season grasses.

Process

1. Mow to 1.5 inches.
2. Apply starter fertilizer (high P) at 1.5 lbs/1,000 sq ft.
3. Ensure seed-to-soil contact: core aerifier (20+ plugs/sq ft), slit-seeder (best if no thatch/compaction), vertical mower, or slicer.
4. Core aerifier: broadcast seed, let plugs dry, drag (chain-link fence) to work seed in.
5. Slit-seeder: two passes, second at 45°.
6. Water 3–4x daily lightly until germination; then transition to deep, infrequent.
7. Mow at 1.5–2 inches until new grass cut twice; raise gradually to 2.5–3.5 inches.
8. Late Nov: winterizer fertilizer.

Resources

• MO Cool Season Renovation
• MO Lawn Calendar