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