Fertilizing a Lawn

A soil test should be made every 2 to 3 years to determine the amounts of lime, phosphorus, and potassium needed by your lawn. A complete fertilizer with a ratio of nitrogen, phosphorus, and potash of 4:1:2 or 4:1:3 can be used in lieu of a soil test, but it is a poor substitute.

The proper amount of fertilizer, nutrient ratio, and time of application will vary with the grasses being grown. Over-fertilization can burn turf, cause excessive growth and lead to disease problems.This is especially true if quick release fertilizers are used. To help reduce turf loss, avoid high nitrogen fertilization of cool season grasses in late spring or summer. Warm season grasses should not be fertilized too soon in the spring or in late fall.

To determine the amount of product required to apply 1 pound of nitrogen per 1,000 square feet, divide the first number on the fertilizer bag by 100.

Example 1.		A 16-4-8 fertilizer. Dividing 100 by 16 = 6.25 pounds of actual fertilizer to be
		applied per 1,000 square feet to provide 1 pound of actual nitrogen.

Example 2.		A 10-10-10 fertilizer. Dividing 100 by 10 = 10 pounds of actual fertilizer to be
		applied per 1,000 square feet to provide 1 pound of actual nitrogen.

Example 3.		To apply 1/2 pound of nitrogen per 1,000 square feet of 10-10-10 fertilizer.
		Divide 50 by 10 = 5 pounds of fertilizer.

Most soils in North Carolina are acidic and often require the application of lime to raise the pH. For most turfgrasses, soil pH should be between 6.5 and 7.0 for optimum nutrient availability. Centipedegrass requires more acidic soil with a pH close to 5.5. Lime may be applied any time during the year. Winter is usually the best time; gentle winter rains minimize runoff, and alternate freezing and thawing help incorporate lime into the soil.

Fertilizers and lime should be applied uniformly with a centrifugal (rotary) or drop type spreader. Apply half the fertilizer in one direction and the other half moving at right angles to the first pass to ensure uniform coverage.

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