Do You Need to Fertilize Your Lawn in the Winter?

Reasons to Avoid Fertilizing

• Most lawns, both cool season and warm season types, enter dormancy or slow down their growth during the winter. Cool season grass types such as fescues, bluegrasses and ryegrasses grow when temperatures are between 60 to 75 degrees Fahrenheit. Warm season grasses, including St. Augustine, centipede, carpet grass and bahia, grow when temperatures are between 75 to 85 degrees Fahrenheit. Providing fertilizer when a grass has slowed its growth may encourage a new flush of growth that's susceptible to freezes and frost conditions.

Fertilizing in the Fall

• Fertilize your cool season lawn in the fall, sometime around Thanksgiving, with a fertilizer high in phosphorous. Phosphorus encourages root growth during the fall and winter months. In addition, lawns should green up faster in the early spring when given phosphorous. Use a fertilizer with an NPK amount such as 13-25-12 on your lawn, as recommended by This Old House. Wait until the early spring to reapply fertilizer.

Fertilize in the Summer

• Fertilize warm season grass types such as bermuda with 1/2 pound of nitrogen in the late summer, as suggested by the University of Arkansas. Gardeners must apply their nitrogen fertilizer at least four to six weeks before the first frost. Frost dates differ depending on where you live. For example, the first frost date in Tuscan, Arizona is December 16 while the first frost date for Denver, Colorado is October 4.

Other Factors

• Avoid piling up snow on your lawn during the winter. The weight of the snow causes soil compaction, which causes poor soil drainage. In addition, a pile of snow raises the risk of your lawn contracting a disease such as snow mold. Fungal spores underneath the snow germinate and spread over the lawn. Distribute snow over the lawn in an even layer. Fertilize your lawn in the spring after it's greened up. Applying a fertilizer on dormant grass increases the weed population.