How to Plant Grass Seed

Cool-season grasses (Kentucky bluegrass, tall fescue, fine fescue, perennial ryegrass) for zones 3 to 7. Warm-season grasses (bermuda, zoysia, centipede, bahia, buffalo) for zones 7 to 10. Transition zone (zone 6 to 7): tall fescue and zoysia work best. Choosing wrong means fighting your climate forever.

Cool-season grass: early September (best) or mid-April (backup). Warm-season grass: late May to June when soil is above 65 degrees. The single biggest factor in success is timing. September seeding for cool-season gives 6+ weeks of perfect growing weather before winter. Spring seeding of cool-season grass faces summer heat before roots develop.

New lawns: grade smooth, remove rocks and debris, apply 2 to 3 inches of compost tilled into the top 4 inches. Overseeding: mow existing grass short (2 inches), core aerate to open the soil, and rake to remove debris. The goal is seed-to-soil contact. Seed sitting on thatch or debris will not germinate.

Rates vary by species. Kentucky bluegrass: 2 to 3 lbs per 1,000 sq ft. Tall fescue: 6 to 8 lbs. Bermuda: 2 to 3 lbs. Zoysia: 2 to 3 lbs. Bahia: 8 to 10 lbs. Buffalo: 3 to 5 lbs. Always use a broadcast spreader at half rate in two perpendicular passes for even coverage. Hand-spreading creates visible gaps.

Use a high-phosphorus starter fertilizer (18-24-12 or similar) at the bag rate. Phosphorus drives root development in seedlings. Do NOT use a weed-and-feed product, which contains herbicide that kills grass seedlings. Apply starter fertilizer at the same time you seed, or within 24 hours.

Keep the top half-inch of soil consistently moist until seeds germinate. This means light watering 2 to 3 times daily for 5 to 10 minutes per zone. Do not let the soil dry out and do not flood it. Germination times: ryegrass 5 to 7 days, tall fescue 7 to 10 days, bermuda 10 to 14 days, bluegrass 14 to 21 days, zoysia 21 to 30 days, buffalo 14 to 21 days.

Once seedlings emerge, gradually shift from light frequent watering to deeper less frequent watering over 3 to 4 weeks. By week 4 to 6, water deeply once or twice per week. This trains roots to grow deep. First mow when grass is 50% taller than your target height (e.g., mow at 4 inches if target is 3 inches).