The annual species is a profilic seed producer. Natural reseedings develop each fall where the grass is managed to produce seed. It is common on roadsides each fall and winter from Texas to Florida. Adaptation and Use. The ryegrasses are best adapted to moist, cool environments where temperatures are not extreme in the winter or summer.
Many European countries have climates ideally suited to the ryegrasses.
In the United States, the northeastern and northwestern states are well suited to ryegrass. In the transition zone, perennial ryegrass may provide a permanent turfgrass. But in the southern states, both species serve as cool season annuals. The perennial species, L. perenne, is more cold tolerant than Italian ryegrass. However, both species are killed by extreme winter temperatures.