Kentucky Bluegrass
Most common cool season grass. High quality lawn, available in blends. Spreads moderately and will fill in bare spots. Goes dormant in hot, dry weather as well as during the cold winter months. Does poorly in extremely shady areas. Not recommended for extremely hot climates and will require supplemental irrigation during hot, dry periods.
Bluegrass seed-blends that include perennial ryegrass, produce a tougher wearing lawn. With the addition of creeping red fescue, the lawn will tolerate shadier areas.
Bluegrass develops a shallow root system that is not very drought tolerant, but will go dormant during extreme conditions. If given intermittent watering during prolonged drought conditions, it will come back.
Shade tolerance: poor
Planting: seed or sod
Mowing height: 1 1/2" - 2 1/2"
Water: needs regular watering, will survive droughts by going into a dormant state.
Fertilization: needs regular fertilization
Maintenance: low
Introduced by: colonists that brought it from Europe.
Kentucky bluegrass grows 18 to 24 inches tall if left uncut and is readily identified by its boat-shaped leaf tip. It spreads by rhizomes and tillers and forms a dense sod. New shoots (rhizomes and tillers) are produced primarily in the spring and late summer. Most shoots produced in the spring remain vegetative. Shoots produced in late summer often terminate in an infloresence the following spring.
The lifetime of a Kentucky bluegrass shoot that terminates in an infloresence ends soon after the seeds mature. During late spring and summer, the shoots of Kentucky bluegrass grow in an erect, or upright, position; whereas, in early spring and fall they become more decumbent. This pattern of growth is a response to day length rather than temperature. During long days shoots grow upright; during short days they become decumbent. Daylength also influences the number of shoots that develop. Significantly more shoots are produced during the short days of early spring than during long summer days.
The length of time between the appearance of new leaves on Kentucky bluegrass ranges from about 10 days in the spring to 22 days in the summer and fall. During winter months few new leaves are produced on Kentucky bluegrass in northern climates. In the transition zone, new leaves and shoots are produced year round.
Leaf blades of Kentucky bluegrass remain green for 10 to 12 days during the growing season and the typical shoot has 3 to 4 green leaves, at any one time. In comparison, bermudagrass typically has 5 to 7 green leaves per shoot and new leaves appear at 7 to 10 day intervals during the growing season.
In the southern U.S., Kentucky bluegrass is limited to the transition zone from North Carolina, through much of Tennessee, northern Arkansas to the panhandle of Texas and Oklahoma. In the western states, Kentucky bluegrass is grown with extensive irrigation.
