Annual ryegrass (Lolium multiflorum) and perennial ryegrass are used to overseed dormant Bermuda grass or other warm-season lawns, to avoid dead-looking winter grass. Ryegrasses adapt to sun or shade, but annual ryegrass will die out in late spring after fall overseeding. According to Clemson University Extension, overseed with 10 lbs. of annual ryegrass per 1,000 square feet of lawn -- seeding half in one direction and the other half in the perpendicular direction -- "raking" with a broom to make sure seed is in direct contact with the soil. Water the lawn lightly two or three times each day until the annual rye germinates. Once the lawn is established and has been mowed a few times, water only when needed.
Hybrid Bermuda grasses established through sodding tend to make finer lawns, but they also require a lot more maintenance. Common types of Bermuda grass are easily established from seed. Bermuda grass thrives in full sun and heat but goes dormant -- turns brown -- when temperatures get cold. It has few disease or pest problems and requires minimal water. Use 1 lb. of hulled seed or 2 or 3 lbs. of unhulled seed per 1,000 square feet of lawn area. After seeding, rake the lawn lightly for good seed-and-soil contact. If there is no rain, water lightly for about two weeks until seeds the germinate -- usually seven to 10 days after seeding.
In terms of seed cost, perennial ryegrass (Lolium perenne) is more expensive than annual ryegrass, but it offers much more -- both as a cool-season overseeding choice for dormant winter lawns and as a year-round turf grass for cooler climates. Perennial ryegrass germinates and gets established quickly but has a finer leaf texture and appearance, competes more effectively against weeds, requires less maintenance, and is fairly disease and pest resistant. It tolerates wear and cold better than annual ryegrass. Because it doesn't tolerate heat at all, when overseeded, perennial rye dies back quickly in spring so Bermuda grass can take over. When overseeding with perennial rye, use 5 to 15 lbs. of seed per 1,000 square feet.
New turf-type tall fescue (Festuca arundinacea) varieties have expanded the overall usefulness of this fast-establishing perennial grass. Easily started from seed, tall fescue is a cool-season or cool-climate lawn grass that tolerates shade, has few disease or pest problems and needs little fertilizer. It also is fairly tolerant of drought in most well-drained soils, though it grows best in fertile soil with a slightly acidic pH. Sow tall fescue seed at the rate of 5 to 8 or 9 lbs. per 1,000 square feet. Because tall fescue is a bunch grass once grown primarily as pasture grass, it can get clumpy and thin out over time. It may need reseeding every few years.