How to calculate grass seed
Seed coverage is based on your lawn area and a seeding rate per 1000 square feet:
Pounds of seed = (lawn area ÷ 1000) × seeding rate
For odd-shaped lawns, split the area into rectangles, work out each, and add them together. The right seeding rate depends on your grass type and whether it's a new lawn or an overseed.
Typical seeding rates
| Use | Rate (lbs / 1000 sq ft) |
|---|---|
| New lawn (cool-season) | 4–6 |
| Overseeding an existing lawn | 2–4 |
| New lawn (warm-season) | 1–2 |
Seeding rate by grass type
Rates vary a lot by seed size — always start with the figure on your bag, but here are typical new-lawn rates:
| Grass | New lawn (lbs / 1000 sq ft) |
|---|---|
| Kentucky bluegrass | 2–3 |
| Tall fescue | 6–8 |
| Perennial ryegrass | 5–7 |
| Fine fescue | 4–5 |
| Bermuda (hulled) | 1–2 |
When to plant
Cool-season grasses (bluegrass, fescue, rye) establish best in early fall, when the soil is still warm but the air is cooling and weeds are fading; spring is a solid second choice. Warm-season grasses (bermuda, zoysia) want late spring to early summer, once the soil has warmed. Either way, seed needs consistent moisture — keep the top inch damp until it germinates.
Seed vs. sod
- Seed is cheaper and has more variety, but takes weeks to establish and needs careful watering.
- Sod gives an instant lawn — order your lawn's square footage plus about 5%, with a pallet covering roughly 450 sq ft.
- Prep matters most. Loosen and level the soil and add starter fertilizer for either option.
How to seed a new lawn, step by step
- Prep the soil. Clear weeds and debris, then loosen the top 2–3 inches with a rake or tiller so seed can reach bare soil.
- Level and grade. Rake the surface smooth, break up clumps, fill low spots, and slope it gently away from the house.
- Add starter fertilizer. Work a high-phosphorus starter feed into the top inch to help young roots establish.
- Spread the seed. Put down half your seed walking one direction and the other half at a right angle, so coverage is even — a broadcast or drop spreader beats sowing by hand.
- Rake and roll. Lightly rake so seed is covered by no more than ¼ inch of soil, then roll it (or walk it down) for good seed-to-soil contact.
- Mulch and water. A thin layer of straw or peat holds moisture; then keep it damp until the seed sprouts.
Watering new grass seed
Moisture is what makes or breaks a new lawn. Keep the top inch of soil consistently damp but not soggy — usually a light watering two or three times a day until the seed germinates (7–21 days). Once the grass is up and a couple of inches tall, water less often but more deeply to drive the roots down. Don't let a freshly seeded lawn dry out at midday; a single hot, dry afternoon can kill seedlings that have only just sprouted.