How to Determine Grass Types

Some types of grasses are healthier for a lawn than others, and understanding the different types of grasses is crucial in maintaining the lawn. The amount of water needed, how high to mow, the type of fertilizer, how much sun or shade needed -- all are dependent upon the type of grass you have. Distinguish grass types by their leaf blades, the arrangement of the leaves, and the presence or absence of ligules and auricles.

It’s important when distinguishing grass types to know the differences among turf grass, weeds and other forms of grasses, as well as the differences between grasses and non-grasses that are sometimes mistaken for grasses. Turf grass is a type of grass that property owners often intentionally grow on their lawns, and can include Kentucky bluegrass, fine fescue and crested wheat grass, among others. Sedges are non-grasses with triangular stems, while grass stems and rush stems are typically flat and round. However, rushes only produce leaves at their bases, while grasses are leafy all across their stems.

Some basic knowledge of grass vocabulary can help you distinguish between grasses that appear identical to the untrained eye. The collar region of the grass structure, which is to the grass what a trunk is to a tree, consists of a leaf blade and a sheath that protects the grass from wind and rain. The blade, or lamina, is the part of the structure above the collar and is often the most easily identifiable.

One of the most basic plant structures used in identifying the various kinds of turf grass is vernation, which refers to the arrangement of young grass leaves within a shoot. In turf grass, these leaves emerge from the center of the structure, but some kinds of turf grass are rolled, their leaves circular and lacking folds, while other varieties are folded, their leaves shaped like the letter V. For example, while annual and perennial rye grasses are otherwise indistinguishable, annual rye grass is rolled, while perennial rye grass is folded.

The collar region of the grass structure may contain ligules and auricles that are instrumental in identification. Ligules are hairy membranes that appear at the place where the leaf sheath and leaf blade meet. Auricles, on the other hand, are thin collar extensions in the same area. Depending on the type of grass, ligules may or may not be present, as they typically appear on weeds and warm-season turf grasses. Auricles may be long, small or non-existent. For example, Kentucky bluegrass and rough bluegrass have short auricles and no ligules, while creeping bent grass has tall ligules and no auricles.