Light Frost Effects on Grass

Grass Growth

• Grass is different from many plants in that the growth occurs at the plant's base instead of the tips. This is why cut grass continues growing. When the plant's tip or blade is damaged, it provides the opportunity for disease to enter the stem, but otherwise the growing portion functions normally. Frost damage mostly occurs to the tips and blades.

Cosmetic Damage

• A light frosting quickly melts off with little damage to most grass. It the frost lasts long enough to freeze the tissues, it may kill a portion of it, which then turns brown. This is unattractive but soon disappears after several weeks of cutting the lawn. A contributing problem is walking across frosted grass. The frozen grass is crushed under the weight, which damages the underlying grass.

Fertilization Timing

• The spring and autumn are traditional times to fertilize grass, stimulating blade growth. Balance against the possibility of frost. Early, lush growth or late-fall growth are particularly susceptible to frost damage. Fertilize after or before all danger of frost passes. Some lawn grass, such as centipede grass, is especially sensitive to frost, which may even kill the plant if severe enough.

Preventing Damage

• Frost flows downhill to the lowest part of the lawn as moisture settles at night. Avoid frost damage by planning your landscaping blocking the moisture flow. Shrubs or other high-growing perennials divert the frost. The University of Florida recommends that homeowners not wet down the lawn to prevent frosting, as this often does more harm than help.