Kentucky bluegrass is by far the favourite and most widely used of all the bluegrass species.

It is one of the more beautiful cool season lawn grasses. It is known for its excellent color, density and texture. It can be purchased in both seed or sod. Kentucky bluegrass seed is commonly included in seed mixtures with cool season turf grasses

The easiest method of identifying K. bluegrass is to look for the boat shaped tip. If you look carefully, the tip of the blade folds together to resemble the bow of a boat. If you pull the length of the grass through your fingers, the tip will split, leaving two small points. Only orchard grass has a similar shaped tip.

Bluegrass’ advantages

Bluegrass forms a dense and attractive turf. For some people, the thin blades are more appealing than wider bladed grasses.

Kentucky Bluegrass has a solid advantage over other cool season grasses by its ability to spread. The fact that it can spread and heal itself when damaged is probably the greatest reason for its popularity. It spreads through the production of rhizomes. See Plant Structure for a complete explanation of rhizomes. Rhizomes are stems that grow horizontally just below the surface of the ground. Each rhizome produces a "node" every few inches along its length from which a new bluegrass plant will sprout. Bluegrass is an excellent choice for busy lawns where backyard activities tend to wear down the turf. Athletic fields will often use a combination of bluegrass and perennial ryegrass. The bluegrass will heal damages and perennial ryegrass is used for its high wear resistance.

Kentucky bluegrass seed is often blended with turf-type tall fescue seed when grown for sod production. Most tall fescue varities don't have the structure to hold sod together very well, but bluegrass does. When sod is harvested, the roots are cut, but the rhizomes from the bluegrass keep the sod from falling apart.

Since the rhizomes grow underground, they help ensure the survival of the plant. It can survive damage that would kill other grasses. Even if the grass is removed at ground level, bluegrass could still grow back because of the underground growing points on the rhizomes.

Kentucky bluegrass has better cold tolerance than other cool season grasses. It can withstand periods of very cold weather that would normally damage fescue or ryegrass. The adaptation zone for bluegrass extends through the cool/humid and cool/arid regions.

However, bluegrass doesn't do well in the south. It is too hot. I have heard from people as far south as Dallas, TX asking how to keep their bluegrass alive. It is always best to choose a grass that does well where you live.