Caring for Your Lawns and the Environment

Reduce runoff and trap pollutants for a healthy yard! Use care when gardening to protect streams, rivers, lakes, estuaries, and coastal waters.

Fertilizer Facts

Fertilizer labels always display three numbers in the same order (for example, 10-6-4)

They represent the percent by weight of three important nutrients:

• Nitrogen (N)—for green, leafy growth.
• Phosphorus (P)—for root and bud growth.
• Potassium (K)—promotes disease tolerance and drought tolerance.

Example: A 40-pound bag of 10-6-4 fertilizer has 10% nitrogen (4 pounds), 6% phosphate (2.4 pounds of P), and 4% potash (1.6 pounds of K).

Fertilizer Rates

A typical lawn feeding is 1 pound of nitrogen per 1,000 square feet.

Table 1 provides some common lawn fertilizer formulations and the amount of each needed for 1 pound of nitrogen:

Table 1. Fertilizer formulations and amounts needed to provide 1 pound of nitrogen

* Rounded to the nearest pound ↲

For other formulations, follow this example using a fertilizer labeled 24-6-6:

• The first number is the percentage of nitrogen—24%.
• To find out how much total product it takes to apply 1 pound of nitrogen, divide 1 pound by 0.24.
• 1 ÷ 0.24 = 4.17. This is equal to a little more than 4 pounds of product.
• If your lawn is 5,000 square feet, multiply 4 pounds by 5. The result is 20. You would need a 20-pound bag of 24-6-6 to cover your lawn.

Nitrogen Fertilizer Guide for Lawns

Table 2 shows when and how much fertilizer to apply to your lawn, depending on the kind of grass you have.

Lawns need some nitrogen each year to remain dense and healthy. Many lawns will do fine with only 1 or 2 pounds of nitrogen per 1,000 square feet each year.

Table 2. Monthly Application Rate^a

^a Dates suggested are for the central piedmont. For the west, dates may be one to two weeks later in the spring and earlier in the fall; for the east, one to two weeks earlier in the spring and later in the fall. ↲
^b In the absence of soil test recommendations, apply about 1 lb of potassium per 1,000 sq ft, using 1.6 lb of muriate of potash (0-0-60), 5 lb of potassium-magnesium sulfate (0-0-22), or 2 lb of potassium sulfate (0-0-50) to bermudagrass, centipedegrass, St. Augustinegrass, and zoysiagrass. ↲
^c Centipedegrass should be fertilized very lightly after establishment. An additional fertilization in August may enhance centipedegrass performance in coastal locations. Avoid using any phosphorus on centipedegrass after establishment unless suggested following a soil test. ↲

Lawn Fertilizer

Excess nutrients damage the waters of North Carolina. Nutrients from fertilizers that move from turf areas into streams and lakes can cause excessive algae growth and harm aquatic life. Follow these tips to make sure you apply only the fertilizer you need:

• Test your soil first! Order your soil test kit by visiting the Nash County Center of N.C. Cooperative Extension. You will be sent instructions on how to take your soil test. The soil test is provided free of charge by the NC Department of Agriculture & Consumer Services.
• Use your soil test results. Your soil test results will tell you how much phosphorus, potassium, and lime that you need. Depending on the history of your soil, you may not even need to apply these nutrients!
• Use the chart. Table 2 will help you determine the amount of nitrogen you need for the type of grass you are growing and the time of application.
• Recycle your grass! You can reduce the amount of nitrogen you add to your lawn by one-third if you recycle your grass clippings.
• Avoid applying fertilizer before heavy rainfall to ensure it is not washed away in runoff before your lawn can absorb it.

Control Erosion

• In North Carolina, sediment is the biggest threat to water quality. Bare soil without vegetation erodes faster than soils with healthy turf cover. Without plants to hold it in place, bare soil can easily wash away in wind, rain, and runoff. Well-managed lawns prevent soil erosion. Reduce erosion in your lawn using these practices: reseed bare spots in your lawn or lay sod to cover them.
• Cover exposed soil in garden areas or natural areas with some type of mulch such as straw, grass clippings, pine straw, pine bark, or leaf litter, especially during winter and just after tillage.
• Extend or redirect your downspout if water is pooling and causing erosion around the outlet. Use gravel or a downspout splash block to slow down flow and protect the surrounding soil and turf.

Mowing Guide

The proper mowing height reduces weed competition and promotes healthy grass growth.

Table 3. Proper mowing heights for common turfgrasses

• Grasscycle! Leave grass clippings on the lawn. They return nutrients to your lawn and reduce the need for additional fertilizer.
• Keep mower blades sharp.

Watering

Proper watering practices help build and maintain a healthy lawn. As a cultural practice, use irrigation to supplement, not substitute for, rainfall—except on very specialized areas or under extreme drought conditions. It is important to schedule irrigation based on sound principles because of the many variables involved, including slope, soil types, and rooting depth. Overwatering your lawn can also lead to erosion and fertilizer runoff.

• In dry spells, allow an established lawn to go dormant, but water every four to six weeks.
• If you want a nondormant lawn, water when grass looks blue-gray with wilted leaves and you leave footprints on it.
• Early morning, ideally before 10 a.m., is the best time to water to discourage disease and increase watering efficiency. Watering in the evening can leave the lawn wet overnight and lead to fungal disease.
• Avoid light, frequent watering; water deeply and less often. Water slowly and wet the soil to a depth of four to six inches (typically 1 inch for clay soils and ½ inch for sandy soils).
• Avoid overwatering to limit water from running off of the lawn.

For more information and assistance in creating effective irrigation plans for turfgrasses grown in North Carolina, refer to Water Requirements of North Carolina Turfgrasses.

Urban and Suburban Lawns

In residential areas, cement, gutters, and storm drains direct runoff from your property and drain directly into streams. Lawn treatments, including fertilizers, herbicides, and pesticides, can all move into our waters through the storm drain system. Take the following steps to prevent pollutants from leaving your property:

• Keep fertilizer off paved surfaces! Always fill or empty spreaders on your grass, garden, or natural areas to avoid fertilizer spills on sidewalks and driveways. If fertilizer does get on a hard surface, sweep or blow it back into the lawn immediately. Do not blow or sweep soil and materials into the storm drain.
• Do not apply fertilizer to frozen ground or dormant turf. The fertilizer won’t be absorbed and is more likely to wash away in runoff or wind.
• Never use fertilizer as a de-icer. It will not melt ice, and it contributes to water pollution.

Carolina Lawns

Be sure to check out our Carolina Lawns: A Guide to Maintaining Quality Turf in the Landscape  publication as well.

Questions?

Have a lawn or garden question? Contact the Extension Master Gardener℠ volunteers in Nash County at the Nash County Agriculture Center. 1006 Eastern Avenue – Nashville, NC 27856.

Acknowledgments

Adapted from Help the Chesapeake Bay by P. Riucciuti and L.L. May, University of Maryland at College Park, Cooperative Extension Service, Home and Garden Information Center.