A: The healthiest lawns are produced when they are watered heavily at infrequent intervals. On an average, the lawn needs about one-inch of water per week, either by rainfall or in combination with irrigation. This one-inch rule will normally soak the soil to a depth of 4 to 6 inches, allowing the water to reach deep into the root system.

Let the lawn completely dry out between watering intervals. Most lawn grasses can tolerate dryer conditions over a reasonable period of time. Water only when a probe or screwdriver is difficult to push into the ground or shows that the soil is dry 4 to 6 inches down.

A: The best time to fertilize a lawn is in the Fall and then Spring. For Northern lawns (cool season grasses), begin the fertilization program as the grass begins to grow in the Spring and reduce applications as the weather gets hotter. When cooler weather returns in the Fall, the lawn can be fertilized again. A late Fall fertilizer application after the first frost can increase lawn quality the following spring.

For Southern lawns (warm season grasses), the fertilization program should start just after Spring green-up and stop about two months before the average frost date in the fall. Frequency of fertilizer applications depends primarily on the amount and form of nitrogen used. The slow-release type fertilizers can adequately feed the lawn from 6 to 10 weeks. If the lawn still looks good and is growing well after 6 to 8 weeks, wait longer for the next application.

A: Fertilizer application rates should be as low as possible and still produce a high quality lawn. Over-fertilization weakens your lawn and causes excess leaf growth. As a general rule, if the amount of Nitrogen (N is the first number in the analysis) is between 5 and 12, the application rate should be 8 pounds per 1,000 square feet.

If the N number is between 12 and 18, the application rate should be 6 pounds per 1,000 square feet. Any N number over 19 should be applied at a rate of 4 pounds per 1,000 square feet. Always follow the recommended rate stated on the bag by the manufacturer.

A: Most turf experts recommend that a lawn fertilizer should have at least one-half of its nitrogen in one of the slow-release forms mentioned above. In most cases, both cool season and warm season grasses will do well when a 3-1-2 or 4-1-2 ratio of N-P-K is used on an established lawn. Some analysis numbers that meet these ratios include the following:

12-4-8
15-5-10
16-4-8
21-7-14
20-5-10

Since individual soil types vary greatly, be sure to check with your local County Extension Office for further information.

A: Yes. Water soaks in at different speeds, depending on the composition of your soil type. If you know your basic soil type, use the following table as a general guide to watering. (Soil test kits and instructions are usually available at lawn and garden centers, and at better hardware stores. Soil test services and information are often available through your local County Extension Office).

Soil Type	Infiltration Inch Per Hour	Time For 1 Inch To Soak In
Sand	2.0 inches	0.5 hours
Sandy Loam	1.0 inches	1.0 hours
Loam	0.5 inches	2.0 hours
Silt Loam	0.4 inches	2.25 hours
Clay Loam	0.3 inches	3.3 hours
Clay	0.2 inches	5.0 hours