Most lawn grasses can be classified as warm season or cool season grasses. Cool season grasses do better in humid, northern climates, while warm season grasses do well in hotter, dry climates. Before choosing the right grass for your lawn, choose among the varieties that thrive in your climate. This will give your lawn its best appearance all-year round, with less chance of dying or becoming discolored.
Cool Season Grasses
This grass type is well adapted to northern climates, growing vigorously in both Spring and Fall, though it may brown during a hot Summer. These are often sold as a blend of several different varieties of the same or similar species, for example, the Kentucky Bluegrass. They can also be sold as a mixture of several different species, like Fine Fescue. Growing a blend or mixture is the normal course of action when seeding a lawn. If one variety doesn't thrive or dies from disease then odds favor one or more of the others taking over and growing in its place.
Tall Fescue, Perennial Ryegrass, Kentucky Bluegrass, and Fine Fescue are the most common types of cool season grasses. The newest strains of Kentucky Bluegrass stand out from their predecessors, as they are now very resistant to disease, and will keep their fine, textured looks without needing too many resources. They are also drought tolerant.
Fine Fescue includes several different Fescue varieties - Creeping Red Fescue, Hard Fescue, and Chewings Fescue - and are mixed in with Kentucky Bluegrass. This mix thrives in both shade and drought.
Perennial Ryegrass is the main grass in cool season mixes. It will germinate quickly and wear well.
Warm Season Grasses
This type of grass does well in southern climates, and has adapted to hot weather, actually going dormant when temperatures become too cold, like near freezing. Zoysia is best able to handle the winter, and is sometimes grown as far north as Pennsylvania. It stays brown in regions where the winters are cold, and is slow to become green in Spring. Though it's a dense grass it's only somewhat tolerant of the shade, and is grown best in areas with a lot of sun.
Bermuda Grass is best grown in the Gulf Coast states, where water sources are abundant. Wearing well, it stays green longer than the other warm season grasses. It also does well in the southern regions of the West Coast. In the southern parts of California it can be started from seed alone, but in the cooler mid-to-northern parts it can only be started from sod sprigs.
Another good choice for the coastal South is St. Augustine Grass. Coarse and adapted to humid coasts, it's not very tolerant of cold weather shade. On the other hand it can handle copious amounts of sun and foot traffic.
A good looking lawn will contain a combination of different grass types, each contributing its own strengths and weaknesses. When choosing your grass mix, look at what proportion the different varieties are mixed to together to determine which one will meet your lawn and landscaping needs best.