They are used primarily for hay production. Creeping rooted varieties are the hardiest and will withstand grazing pressure and adverse conditions better than the other two categories. Three Categories of Alfalfa Alfalfa varieties are grouped into three categories because of different characteristics. Understanding the relationship between root reserves and how the plant grows is important if the stand is to survive for any length of time under a grazing situation. With the initiation of growth in the spring or following removal of the top growth by cutting or grazing, carbohydrate reserves in the roots are utilized to produce new top growth.
Reserves are lowest during the early vegetative period and highest at full maturity.
Usually root reserves decrease between full bloom and the mature seed state as tiller formation or new vegetative growth occurs. Once alfalfa reaches 8 to 10 inches, food reserves begin to replenish as the plant produces more food than it needs for maintenance and growth. Replenishment is complete by the full bloom stage. For alfalfa to persist the root reserves should be as close to maximum as possible when the plants are going into the winter. Reserves are used to develop heat and cold tolerance to maintain life during dormancy and to get the plants started next spring.