Basics of Grass Growth

A grass plant is composed of multiple individual growth units called tillers (stems or culms). The base of each tiller is connected to a portion of the root crown, which is the collection of the roots from all of the tillers. Each tiller contains several or more growth segments (technically called phytomers). A growth segment is composed of the same four parts:

• the leaf, which includes the leaf blade and the leaf sheath, the part of the leaf that wraps around and is attached to the stem;
• the node, the point on the stem where the leaf sheath attaches to the stem;
• the internode, the area between two nodes; and
• the axillary bud, which occurs at each node.

There are two types of tillers: vegetative and reproductive. Vegetative tillers consist primarily of leaves (Figure 1). Reproductive tillers produce a stem, seedhead, roots, and leaves (Figure 2).

Figure 1. A vegetative grass tiller. Leaf 1 is oldest, and leaf 8 is just being exerted. The enlarged area of the crown shows the apical meristem that produces the leaves.

Figure 2. A reproductive grass tiller. This tiller has a stem (or culm) and seedhead that differs from the tiller in Figure 1. Intercalary meristematic tissue at the base of the leaf blade, near the ligule (insert), allows for leaf expansion.

Adapted from: M.J. Trlica. 2006. Grass Growth and Response to Grazing. Colorado State University Extension Publication no. 6.108.

Additional References on Grass Growth

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