This is the most frequently asked question of The Lawn Institute by homeowners. The answer depends on a number of factors, such as, general geographic location for turfgrass adaptation (cool season or warm season grasses), the amount of sun and shade, the amount of traffic or play, watering practices, and the general level of maintenance. Answers to these questions will help you and the garden center retailers make a better decision as to which quality seed mixture or blend to buy for your geographic location and environmental conditions. What are your choices or options?
The first order of business is to have a general understanding of the grass species that grow best in your area of the country. Let’s start with the northern lawns, which are identified with the cool season grass species; namely, Kentucky bluegrass, fine fescues, perennial ryegrass, and turf type tall fescue.
Cool Season (Northern)
Kentucky Bluegrass – This is by far the “Number One” lawngrass for the northern parts of the country. It’s a native of Europe and Asia and came to North America several hundred years ago. This grass has been and is used for about every turf area except golf course putting greens.
Many older lawns were planted with common Kentucky bluegrass some years ago. In the last several years, there has been major breakthroughs in the breeding and development of new, improved bluegrasses.
The new, named bluegrass varieties found in quality blends and mixtures are more heat and drought tolerant, have greater insect and disease resistance, and in many cases are more shade tolerant; though they grow best with an abundance of sunlight.
Once established, Kentucky bluegrass spreads by underground stems called rhizomes. Thus, it is capable of filling in to heal areas of thin grass and help crowd out weeds. But, they germinate slowly and are often times sold in mixtures with other faster germinating cool season grasses, such as, perennial ryegrasses and fine fescues. However, in seed mixtures, the Kentucky bluegrasses should be the dominant species by percentage and weight. It can be established by seed or sod.
Perennial Ryegrass – The new turf type perennial ryegrasses are the most versatile of any lawngrasses available. Compared to the old common types, the new turf types have narrower leaf blades that cut clean with a good sharp mower. They are darker green and are more resistant to disease and insect injury. They have improved tolerance of hot weather when not stimulated with too much fertilizer.
Perennial ryegrass germinates quickly and is often found in mixtures with the slower germinating Kentucky bluegrass, and fine fescues . . . helping to prevent soil erosion during lawn establishment. They can also be planted by themselves and are good for overseeding into a poor quality turf. Another valuable quality is that perennial ryegrass has generally better wear tolerance than Kentucky bluegrass. They are often found in quality sod as well. The perennial ryegrasses should not be confused with the annual ryegrasses, which are generally not recommended for use in a permanent lawn.
Fine Fescue – There are several grasses called fine fescue, including red, Chewings, and hard types. These grasses are not seeded alone, but generally used in mixtures with Kentucky bluegrass and/or perennial ryegrass. Fine fescues germinate quickly and establish in either sun or shade. They are the most shade tolerant of all lawngrasses. The fine fescues have low fertilizer requirements and do not compete with the slower growing grasses in the mixture. They function as good companion grasses in lawn establishment and develop into a permanent component that helps create a high degree of hardiness and ease of maintenance.
As conditions favor the bluegrasses, fine fescues give way and provide needed room; as conditions may reduce bluegrass growth, the fine fescues move in and fill thin spaces so that a quality turf is maintained. If shade is a factor in the lawn, fine fescues should be a significant percentage (30 – 50%) of the lawnseed mixture.
Turf Type Tall Fescue – Tall fescue has traditionally been used in the transition zone (Eastern portion of Zones 6 & 7) and the upper south, but the development of new turf type tall fescues has made them compatible in the cool, humid regions as well. These new tall fescues are greatly improved in comparison with the old common types, including Kentucky 31. They have finer leaf blades that create a denser turf, have improved resistance to disease and insect injury, and are tolerant of the higher summer temperatures characteristic of many areas throughout the north and upper south.
Turf type tall fescues have good drought and shade tolerance. They are often sold as blends of two or more named varieties. However, mixtures in combination with a small amount (5-10%) of improved Kentucky bluegrass is becoming more common; the more aggressive bluegrass used to fill in thinning areas which can occur with the tall fescues. Selecting the best grass for your lawn in the south depends primarily on two factors: how much sun your lawn will receive and its geographic location within the warm season grass region. The primary choices for southern lawns are: Bermudagrass, St. Augustine, centipedegrass, zoysia, tall fescue, and buffalograss.
Warm Season (Southern)
Bermudagrass – Bermudagrass originated in Africa, where it evolved under a hot-dry climate. It is the most predominant species throughout the south and southwest. It is a very aggressive grass that demands full sun and has very little tolerance or shade. There are two basic groups of bermuda . . . those that can be established by seed, and those that can only be planted from sprigs or sod. Seeded bermudas are less costly to establish and tend to be cheaper to maintain.
The best time to start a bermuda lawn from seed is from late spring to late summer when nighttime temperatures stay above 65 degrees. Sodding is the most common method of establishing a hybrid bermuda lawn, although sprigging is also used. Bermuda lawns can be sodded anytime of the year, but the best time is during the summer months. This species does not have any significant disease or insect problems when properly mowed, fertilized and watered. With the exception of buffalograss, seeded bermudagrasses have the lowest water and fertilization needs among the warm season grasses. Bermudas go dormant and turn brown with the first cold weather in the fall and don’t renew growth and color until soil temperatures get back to at least 60 F.
St. Augustine – St. Augustine is a popular and widely used lawn grass in the humid coastal areas of the south from Florida to California. Its popularity is due in great part to having the greatest shade tolerance of the warm season grasses, while it also thrives in full sun. St. Augustine, which has a wider leaf blade than most other lawngrasses, is relative easy to establish by sodding or plugging with proper fertilization and watering, and will do well in most soil types. However, it is quite sensitive to freezing temperatures and winter kill; thus, limiting its use in the upper south. The available varieties vary greatly in their cold tolerance. Make sure the one you select has a good record of winter survival in your area before you buy. Also, only those varieties that are labeled as resistant to disease called St. Augustine Decline (SAD) should be purchased.
The older lawns that have SAD can be improved by planting plugs of the new SAD-resistant strains. The best time to sod or plug St. Augustine is during the summer months when temperatures remain above 65 degrees.
Centipedegrass – Centipedegrass is well adapted to most soils and climatic conditions in the south and upper south, but is not so well adapted to the more arid regions west of the Mississippi.
The leaf blade is medium in texture and forms a good, low growing, dense turf. It is not as shade tolerant as St. Augustine, but more so than bermuda. Centipede has excellent drought tolerance, but low wear tolerance and a slow growth rate. It can either be established by seed or vegetatively by sod or springs. Centipede remains green throughout the year in mild climates, but the leaves can be killed during hard freezes. It does not have a true dormant state like bermuda, and resumes growth whenever temperatures are favorable.
Zoysiagrass – Zoysia is considerably more tolerant of shade than bermuda. Because zoysia is the most winter-hardy of the warm season grasses, it does better in the upper south regions and the transition zone. It is most often planted as sod or plugs, but it may take as much as two growing seasons for plugs to form a complete lawn cover. Once established, it has excellent wear tolerance and good drought tolerance.
There are two basic types of zoysia available: Emerald and Meyer. Emerald has a much finer leaf blade of the two, though both can form a dense green lawn. Zoysia has no significant disease or insect problems when proper mowing, watering and fertilization practices are followed.
Buffalograss – This is the only turfgrass native to the North American plains from Texas to Canada. It has fine leaf blades that are blue-green in color, but will not develop as dense a lawn as other warm season grasses. There is a growing interest in buffalograss for low maintenance lawn areas. It can survive extreme drought conditions, has low fertility requirements, and generally will not grow more than 4 to 5 inches when left unmowed. However, buffalograss has little shade tolerance and does not do well in humid areas. Most of the new varieties are available only as sod, though there are a growing number of named varieties available as seed. Buffalograss is not for everyone, nor is it ideal for many lawns. But its excellent drought tolerance and low maintenance requirements have increased interest among homeowners in the upper south, semi-arid, and great plans regions.
Turf Type Tall Fescue – Even though turf type tall fescue generally is considered a northern, cool season grass, its use in the upper south is increasing; primarily in place of St. Augustine on well-shaded lawns. Tall fescues also have good heat and drought tolerance for the southern summers and can survive cold winter temperatures with relatively few problems. It is a popular species because it stays green all winter, even when dormant. The use of two or more tall fescue varieties in a blend often provides for a heartier lawn than using a single older common variety like K-31.
-The Lawn Institute