| Grass | New lawn | Overseed | Season | Notes |
|---|---|---|---|---|
| Kentucky bluegrass | 2 lb | 1 lb | Cool | Slow to germinate (14-21 days) but spreads by rhizomes and repairs itself. |
| Perennial ryegrass | 8 lb | 5 lb | Cool | Germinates in 5-7 days. Bunch-type, so it does not fill gaps on its own. |
| Tall fescue | 9 lb | 5 lb | Cool | Deep rooted and the most drought and traffic tolerant cool-season grass. |
| Fine fescue | 5 lb | 3 lb | Cool | The shade option. Poor traffic tolerance. |
| Bermudagrass (hulled) | 2 lb | 1 lb | Warm | Needs full sun and soil above 65F to germinate. Very aggressive. |
| Zoysia | 2 lb | 1 lb | Warm | Slow to establish from seed - most zoysia lawns are sodded or plugged. |
| Centipede | 0.5 lb | 0.25 lb | Warm | Very low rate; seed is tiny and the grass is slow growing. |
| Bahiagrass | 8 lb | 5 lb | Warm | Tolerates poor sandy soil. Coarse texture, seed heads through summer. |
Why the rates differ so much
It comes down to seed size. Kentucky bluegrass has roughly 2.2 million seeds per pound; tall fescue has about 230,000. Ten times the seeds per pound means a tenth of the weight for the same seeding density, which is why bluegrass goes down at 2 lb per 1,000 ft² and fescue at 9.
Growth habit matters too. Bluegrass and bermudagrass spread by rhizomes and stolons, so they knit together and repair thin patches themselves — you can seed them lighter and let them fill in. Ryegrass and tall fescue are bunch-type: each seed makes one clump and stays there, so gaps you leave are gaps you keep.
Cool season and warm season
Cool-season grasses (bluegrass, ryegrass, tall and fine fescue) grow hardest in spring and autumn, go semi-dormant in summer heat, and stay green through mild winters. Sow late summer to early autumn. They dominate the northern two-thirds of the US.
Warm-season grasses (bermuda, zoysia, centipede, bahia, St Augustine) grow through summer heat and go brown and dormant after the first frosts. Sow late spring to early summer, once soil is reliably above 65°F. They dominate the South.
The band across the middle of the country where neither group is fully happy is called the transition zone, and it is the hardest place to grow a lawn. Tall fescue is the usual answer there.
Buying seed
Read the label, not the front of the bag. It legally has to state purity, germination percentage, the date germination was tested, weed seed content and "other crop" content. A cheap mix carrying 5% "other crop" and a two-year-old germination test is not cheap.
Watch for high percentages of annual ryegrass in bargain mixes. It germinates fast and looks like instant success, then dies at the end of the season, because it is an annual. Perennial ryegrass is a different plant, and the one-word difference on the label is the whole story.
Common questions
How many pounds of grass seed per 1,000 square feet?
Tall fescue 9 lb, perennial ryegrass 8, fine fescue 5, Kentucky bluegrass 2, bermudagrass 2, centipede 0.5 — for a new lawn. Halve for overseeding.
Which grass seed germinates fastest?
Perennial ryegrass, in 5-7 days. Tall fescue takes 7-12 days and Kentucky bluegrass 14-21, which is why bluegrass lawns are so often started from sod.
What is the difference between annual and perennial ryegrass?
Annual ryegrass dies at the end of one season. Perennial ryegrass persists. Cheap seed mixes often carry a lot of annual ryegrass because it germinates fast and looks like success.