How much grass seed do I need?
Seed is measured in pounds per 1,000 square feet, and the right rate depends almost entirely on the grass. Bluegrass seed is so small that 2 lb covers 1,000 sq ft; tall fescue seed is large and needs 6–9 lb for the same area.
| Grass | New lawn (lb / 1,000 sq ft) | Overseeding | Source |
|---|---|---|---|
| Kentucky bluegrass | 1.5–2 | 0.75–1 | Purdue |
| Tall fescue | 6–9 | 3–4.5 | Purdue |
| Perennial ryegrass | 7–9 | 3.5–4.5 | UW Extension |
| Fine fescue | 3.5–4.5 | 1.75–2.25 | UW Extension |
| Bluegrass + 10–15% ryegrass | 3–4 | 1.5–2 | Purdue |
| Bluegrass + 30–50% fine fescue (shade) | 4–5 | 2–2.5 | Purdue |
| Bermudagrass (hulled) | 1–2 | 0.5–1 | Univ. of Kentucky |
| Zoysiagrass | 1–2 (pure live seed) | 0.5–1 | Univ. of Arkansas |
The overseeding column is our planning assumption — half the new-lawn rate — for thickening a lawn that still has grass. For a renovation where most of the lawn is dead or killed off, use the new-lawn rate.
How much grass seed per square foot?
Per square foot the numbers get small: tall fescue at 6–9 lb per 1,000 sq ft is 0.006–0.009 lb, about 3–4 grams per square foot. That's why spreaders and bag labels use the per-1,000 rate. For a bare patch, measure it and enter the square feet — even a 3 × 3 ft spot (9 sq ft) of tall fescue needs only about an ounce of seed.
Coated seed — seed wrapped in a moisture-holding or fertilizer coating — weighs more per seed, so its bag rate is higher. If the bag gives a higher rate than the table, follow the bag.
Getting seed to grow
The seed rate is the easy part. What decides whether it comes up:
- Timing. Cool-season grasses (fescue, bluegrass, ryegrass) do best seeded in late summer to early fall; warm-season grasses (bermuda, zoysia) in late spring once soil is warm.
- Seed-to-soil contact. Rake bare soil smooth, spread half the seed in one direction and half crosswise, and rake it in about 1/4 in. On an existing lawn, mow short and core-aerate or slit-seed first.
- Water. Keep the top inch moist — light watering once or twice a day — until the new grass has been mowed twice.
Starting from bare dirt? Spread topsoil first with the topsoil calculator. Need a finished lawn now instead of in eight weeks? Compare the cost of sod.
