Winter Grass Fertilizers

Slow-Release Fertilizers

• In the summer months when microbes in the soil are actively breaking down fertilizers and making nutrients available to plants, you should use quick-release fertilizers. In winter, however, this activity slows down, and you should use a slow-release winter grass fertilizer. These fertilizers will allow important nutrients to impregnate the soil over several months.

Nutrients in Winter Grass Fertilizers

• Nitrogen is one of the most important nutrients for plant growth, and it can be especially important for grass. Winter grass fertilizers should contain at least one pound nitrogen for 1,000 square feet of lawn. Other nutrients in fertilizers are phosphorus and potassium, which is also called potash. Most winter grass fertilizers contain more potassium than phosphorus. These nutrients are often identified as N, P and K, and many grass fertilizers range from an N-P-K rating of 20-0-0, which would contain 20 percent of nitrogen and no phosphorus or potassium, to 30-5-15. Most grass fertilizers will contain more nitrogen than other nutrients.

When to Fertilize

• Many warm-weather types of grass go dormant as temperatures drop, and it is important to fertilize just before this happens. When grass goes dormant, growth above the ground stops in order to conserve energy and protect from frost. Since grass blades aren't taking up nutrients, the roots can develop during the winter. You want to fertilize before dormancy in order to provide the roots with the nutrients they need to grow strong and healthy. It is important not to fertilize when grasses are stressed because this could burn the roots.

Before Fertilizing

• Before you spend money on a fertilizer, it is a good idea to get soil tested for pH level, moisture, nutrient levels and other factors. Understanding what soil is lacking will help you choose the fertilizer that will create optimum conditions for growth. Often, university extensions will offer soil testing services for a modest fee, but you can also ask about testing services at your local lawn and garden center. Some home improvement and garden stores also sell soil testing kits for home use.