Home Lawns Preparing Your Lawn

Preparing Your Lawn

Choosing the right grass

Many lawn grasses are described in gardening websites and books. The choice depends largely on characteristics of the grass and the intended site for it to grow. To most, grass may be simply grass, but there are many differences in species and even within a species. Turf evaluators look at many factors to determine the best grasses to put on the market. These include:

Growth habit
Appearance quality
Ease and rate of establishment
Maintenance needs
Adaptability to shade
Wear tolerance
Ability to recover from damage
Cold hardiness
Susceptibility to pests and diseases

How lawn grasses grow

Grasses may grow in bunches or have the ability to spread via modified stems. Bunch-type grasses grow in clumps and spread very little via tillers from the base of the plant. Grasses with this type of growth habit do not readily recover from damage or fill-in bare areas on their own. Rhizomes are stems that grow horizontally underground. Stolons are horizontal stems that grow above the soil surface. Grasses with either of these types of growth habit can readily fill-in adjoining bare areas and also recover more readily when damaged.

Cool-season versus warm-season

There are two types of grasses – cool-season grass and warm-season grass. True to their names, cool-season grass is green and actively growing during the cooler times of year (spring and fall). Warm-season grass is green and actively growing during the hotter times of year (summer). For Illinois lawns, cool-season grass gives us the longest green period. Warm-season grass is more common in the southern US but there are some species that can grow in Illinois. Because most Illinois lawns are cool-season grass, this website will focus on those particular species. Some warm-season grass species that can be found in Illinois include zoysiagrass and buffalograss.

Common cool-season turf grass species

These are the primary lawn species suggested for Illinois. All are cool-season grasses, growing most actively in spring and fall.

Kentucky bluegrass

Poa pratensis is by far the most popular species used in home lawns in Illinois, due to high quality appearance, hardiness, and recovery ability. Kentucky bluegrass spreads by rhizomes. Most cultivars of Kentucky bluegrass require moderate to high levels of maintenance (such as fertilizing, watering, and mowing) to maintain high quality. Kentucky bluegrass prefers full sun, although a few cultivars have tolerance to light shade. Kentucky bluegrass is slow to establish by seed, yet readily available as sod.

Fine fescues

Fine fescues require less maintenance and many adapt to shade. The fine fescues encompass a grouping of various fescue species and include red fescue, chewings fescue, sheep fescue, and hard fescue. Leaf width is narrow, and most are bunch-type grasses (red fescue has rhizomes). Wear tolerance (such as foot traffic) and recovery ability of fine fescues is fair. Maintenance levels are generally low, especially fertilizer needs, and fine fescues may decline in full sun when mowed frequently. Fine fescues are installed via seed and are often used in seed mixtures of grass seed for areas of differing light intensities. These are considered one of our most shade tolerant species, but still require at least two to four hours of direct sunlight every day.

Perennial ryegrass

Lolium perenne offers quick establishment and good wear tolerance. Perennial ryegrass is a bunch-type grass with quality very similar to Kentucky bluegrass. Maintenance needs are moderate to high, similar to Kentucky Bluegrass. Because of its good germination rate, perennial ryegrass works well when mixed with Kentucky bluegrass which has a lower germination rate and slower establish time. Perennial ryegrass can be used to patch in bare spots for quick color but is not often suggested to be used alone as a lawn grass. Perennial rye has poor cold tolerance and commonly suffers winter damage in Northern Illinois

Turf-type tall fescue

Schedonorus arundinaceus is relatively new to the commercial lawn care industry. Tall fescue has traditionally been seen more in pasture applications, but due to the plant’s attributes of drought tolerance and good performance in difficult environments, breeders have worked to create tall fescue varieties that more resemble Kentucky bluegrass. The results of this breeding has led to turf-type tall fescues (TTTF) which have become fairly popular in recent decades. Through efforts of selective breeding turf-type tall fescue has a narrower, finer texture leaf, with a darker green color, and denser appearance than its pasture-type. TTTF develops a larger root system than Kentucky bluegrass and stays green longer during the hot summer months when most cool-season grasses go dormant. Because of its heat tolerance, TTTF is a good option for those in Southern Illinois. TTTF is also tolerant of partial shade and withstands temporary flooding. Read more about turf-type tall fescue including a list of the top varieties from the National Turf Evaluation Program. Read more from Good Growing on their Tall Fescue blog.

Suggested mixtures

Lawn seed products may be mixtures or blends. Seed mixtures are combinations of two or more species of grass, such as Kentucky bluegrass and perennial ryegrass. Blends of grass seed are combinations of two or more cultivars/varieties of a single lawn species. Cultivars (or varieties) are considered selections of a species. Cultivars may offer a variety of traits that set them apart from others in the species, including resistance to diseases or other stress, or perhaps improved color or hardiness. When combined in blends, each cultivar offers a variety of features to contribute to a diverse stand of lawn grasses able to withstand a number of stresses and problems better than one cultivar by itself.

Combining grass species and cultivars together helps create a uniform yet diverse stand of grasses in a lawn. Mixtures and blends of Kentucky bluegrass, perennial ryegrass, and fine fescues are suggested for lawn use in Illinois. The decision of which specific mixture or blend to use is based on site conditions, maintenance program, and use factors. Here are some examples.

Full Sun Areas

Kentucky bluegrass blend (3-5 cultivars)
Kentucky bluegrass/perennial ryegrass mixture
Tall fescue blend* (high traffic areas or hot, dry sites)
Fine fescue blend (low maintenance lawn - infrequent mowing)
Kentucky bluegrass/perennial ryegrass/fine fescue mixture

*Juvenile tall fescue (newly seeded in the fall) may not be completely winter hardy in northern Illinois and may require overseeding to maintain acceptable quality.

Sun/Shade

Kentucky bluegrass/fine fescue mixture
Tall fescue blend*

*Juvenile tall fescue (newly seeded in the fall) may not be completely winter hardy in northern Illinois and may require overseeding to maintain acceptable quality.

Deep Shade

(in order of need for light)

Fine fescue blend (dry shade)
Rough bluegrass (wet shade) - low quality lawn
Full shade tolerant ground cover
Woodland natives (ferns, wildflowers)
Mulch to cover soil

**Shade-tolerant grasses have a limit on how much shade they can tolerate. Even the most shade tolerant species requires 2 to 4 hours of direct sunlight each day.