Pros
Winter Rye grass is an annual grass that lives for one season and dies out. Rye grass is useful for creating a green lawn in the winter by overseeding an existing lawn.
Rye can also be mixed with other seed types such as bermuda or centipede for winter hydroseeding. The rye will come up immediately while the warm season seed will remain dormant until spring. About the time the rye is dying out, the warm season grass will be well established.
Annual rye grass is an excellent choice for erosion control because it establishes quickly. Although it is annual, it can reseed itself naturally and grow new turf each fall if conditions are favorable.
Winter rye grass usually establishes itself in about 3 weeks.
Cons
Rye is not a year-round lawn. It is temporary (an annual) and will typically not come back the following year throughout most of the South.
Of all turfgrasses used in the Southern US, ryegrass probably has the highest maintenance issues. It is not drought tolerant and needs regular watering. Mowing, watering, fertilization and pest management for ryegrass is higher than for any of the other turfgrasses found in the Southern US. Ryegrass is a fast grower in the spring and requires twice weekly mowing at the taller heights.
Insects and diseases are constant threats to ryegrass. In the fall, during establishment of ryegrass, diseases caused by Pythium, Rhizoctonia and Fusarium can cause damping off of new seedlings. Leaf spot, dollar spot and rust are potential problems in the spring. Regular preventive applications of fungicides are needed on established ryegrass turf such as found on golf courses and athletic fields.
If you are simply growing annual rye for winter color, these issues should not be of great concern. Be sure to water your winter rye regularly and apply a fungicide when the new growth is established.