Grass seed calculator
Seeding a new 1,000 sq ft lawn takes 5 to 8 lb of tall fescue, or 1.5 to 2 lb of Kentucky bluegrass, at the University of Tennessee's rates. Overseeding a thin lawn takes about half.
Seeding rates by grass
Rates are given in pounds of seed per 1,000 square feet. They vary so much between grasses because the seeds do: small-seeded grasses such as Kentucky bluegrass and bermudagrass need fewer pounds than large-seeded ryegrass and tall fescue to put the same number of plants in the ground. The calculator uses the University of Tennessee Extension's table, and the middle of each range for the bag count.
| Grass | New lawn, lb per 1,000 sq ft | Overseeding, lb per 1,000 sq ft | New lawn, lb per 5,000 sq ft | Days to sprout |
|---|---|---|---|---|
| Tall fescue | 5 to 8 | 2.5 to 4 | 25 to 40 | 6 to 12 |
| Kentucky bluegrass | 1.5 to 2 | 0.75 to 1 | 7.5 to 10 | 14 to 21 |
| Fine fescue (chewings, red or sheep) | 3 to 5 | 1.5 to 2.5 | 15 to 25 | 6 to 14 |
| Perennial ryegrass | 4 to 6 | 2 to 3 | 20 to 30 | 3 to 7 |
| Annual ryegrass | 4 to 6 | 2 to 3 | 20 to 30 | 3 to 7 |
| Bermudagrass, hulled seed | 0.5 to 1 | 0.25 to 0.5 | 2.5 to 5 | 10 to 20 |
| Bermudagrass, unhulled seed | 1 to 2 | 0.5 to 1 | 5 to 10 | 14 to 21 or longer |
| Centipedegrass | 0.5 to 3 | 0.25 to 1.5 | 2.5 to 15 | 10 to 20 |
| Zoysiagrass (japonica) | 0.5 to 3 | 0.25 to 1.5 | 2.5 to 15 | 10 to 14 |
Other extension services give slightly different figures. The University of Maryland, for instance, sows turf-type tall fescue at 6 to 8 lb and Kentucky bluegrass at 2 to 3 lb per 1,000 sq ft when renovating a lawn. If your seed bag gives its own rate, choose "Other" and enter it.
Area: 50 ft × 20 ft = 1,000 sq ft
1,000 sq ft ÷ 1,000 = 1 × 5 to 8 lb = 5 to 8 lb
6.5 lb ÷ 7 lb a bag = 0.93, rounded up to 1 bag
Overseeding a thin lawn
Overseeding thickens an existing lawn rather than starting one, so it needs less seed. Nebraska Extension puts it at about half the rate for a new seeding, and Maryland's overseeding rates follow the same pattern: 4 lb of tall fescue, 1.5 lb of Kentucky bluegrass and 2.5 lb of fine fescue per 1,000 sq ft. Choose "Overseeding a thin lawn" and the calculator halves the rate.
Sowing and the first weeks
Maryland suggests splitting the seed in two and spreading one half north to south and the other east to west, which evens out the coverage. Cover a new seeding with straw, spread so that 50 to 75 percent of the soil is hidden; the University of Tennessee puts one 50 lb bale at about 1,000 sq ft, and the straw seldom needs removing later. Water lightly every day for the first few weeks, about ⅛ to ¼ in, or 75 to 150 gallons per 1,000 sq ft, then less often as the roots grow. Don't be tempted to sow extra: too much seed gives a crowded stand of weak, disease-prone seedlings.
Sources
- Turfgrass Establishment: Seeding (W160-B), University of Tennessee Extension (Tom Samples and John Sorochan), October 2007. Seeding rates in lb per 1,000 sq ft: Kentucky bluegrass 1½–2, chewings, red and sheep fescue 3–5, tall fescue 5–8, annual and perennial ryegrass 4–6, hulled common bermudagrass ½–1 (double for unhulled), centipedegrass and zoysia ½–3; days to germinate; one 50 lb bale of straw covers about 1,000 sq ft; water ⅛–¼ in (75–150 gallons per 1,000 sq ft) daily for several weeks.
- Lawn Renovation and Overseeding, University of Maryland Extension, updated 13 September 2023. Renovation rates: turf-type tall fescue 6–8 lb, Kentucky bluegrass 2–3 lb, fine fescue 4–5 lb per 1,000 sq ft; overseeding 4, 1.5 and 2.5 lb; sow half the seed one way and half across it; cover with straw.
- Dormant Lawn Seeding, Nebraska Extension in Lancaster County (Sarah Browning), 3 November 2019. Overseeding a thin lawn usually takes half the seed of a new seeding.