Kentucky bluegrass and fescue are two varieties of turfgrass used throughout the United States. Both grasses have many varieties with common characteristics, adapted for use in different areas throughout the country. Kentucky bluegrass and fescue are both used as cool-season grasses for late-season coverage and overseeding.
Most Kentucky bluegrass varieties are adapted for turf use. According to Penn State University, only three forage-type varieties were released since the 1950s. Fescue is a larger grass genus, composed of more than 100 species of grasses. Tall fescue is the most common turf grass type.
Kentucky bluegrass is a medium height grass, growing 18 to 24 inches high. It has a boat-shaped leaf tip. Kentucky bluegrass blades produced in the spring do not have an inflorescence, while blades grown in the late summer do.
Tall fescue grows in long, individual tillers that end in an inflorescence. Fescue grass grows between 3 and 4 feet in height. The leaf is smooth, glossy on the undersides and is serrated along the edge. The inflorescence is 3 to 4 inches long.
Kentucky bluegrass, when established from seed, requires 2 to 3 lbs. of seed per 1,000 square feet, notes the Texas Cooperative Extension. Seeding rates lower than 2 to 3 lbs. take more time to cover an area. Fescue requires a greater seeding rate at 6 to 8 lbs. per 1,000 square feet. Fescue also requires uniform seeding using a hydroseeder or mechanical seeder.
Fescue grasses have a resistance to low-fertility conditions, growing without proper nutrition. However, 3 lbs. of nitrogen per 1,000 square feet per year is recommended. Kentucky bluegrass is a heavy feeder and requires regular fertilizer application. Fescue needs 5 to 6 lbs. of nitrogen per 1,000 square feet in the first year, going down to 2 to 3 lbs. in the second year.
Kentucky bluegrass requires regular dethatching to keep it healthy. The recommended mowing height is between 2 and 3 inches to keep a dense coverage. Fescue requires a greater height, 3 inches, to prevent damage during the summer, while 2 inches is adequate during the fall.