Nearly comparable to bluegrass and tall fescue in appearance, durability, toughness, drought resistance and maintenance, the distinct advantage of perennial ryegrass is how readily it germinates. Unlike Kentucky bluegrass and tall fescue seedlings which need several winter months to mature before they are able to withstand summer heat, spring planted perennial ryegrass seedlings develop roots quickly enough to survive northern summers. Use it for spring seeding projects that you can’t delay until fall.
Quick-germinating perennial ryegrass seed is often included in bluegrass or tall fescue mixtures to provide some welcome green in newly seeded patches or lawns while the other seeds are taking their good old time to germinate. It will stand some shade but works best in mostly sunny areas. It grows best in the North where the climate is moderate, the area bounded by Pittsburgh on the north and Raleigh on the south. Grown too far north, it suffers from the severe winters; grown too far south, it suffers from the prolonged hot summers, stresses which make it vulnerable to disease problems. Buy a perennial ryegrass mixture with from 15 to 40% bluegrass in the mix. It upgrades the durability and general appearance of a turf composed mainly of improved ryegrass varieties.
Pythium fungus is common in ryegrass lawns when the temperature and humidity are high. These grasses are also susceptible to brown patch and red thread. If perennial rye is mixed with other types of grass in the lawn, however, an attack of one of these fungal diseases will not ruin the entire lawn.