Lawn care calendar for West Virginia: when to fertilize and seed

Feeding dates and rates are the WVU Extension guideline for an established lawn; seeding and aeration dates are from its Establishing a Lawn and Lawn Aeration pages.

Which grasses grow where in West Virginia

WVU Extension’s seed guidance treats Kentucky bluegrass, tall fescue, perennial ryegrass and fine fescues as the main lawn grasses. Bluegrass prefers full sun and gives darker color and better mowing quality, but has higher fertility needs than fescues. Fine fescues do well in shade and tolerate drought and taller mowing, and mixes often include ryegrass as a nurse grass that fills in fast while the main grass establishes.

The WVU pages cover cool-season lawns first and mention warm-season grasses only for timing: seeded late spring or early summer, and aerated in fall. They do not give a separate warm-season feeding calendar, so lawns of zoysiagrass or bermudagrass in the Ohio and Kanawha valleys should follow the product and soil-test advice for those species.

Frost dates from NOAA

Dates are the NOAA 1991-2020 normals for the last spring and first fall 32 F freeze at 50% probability. Charleston Yeager Airport averages April 16 and October 26, Morgantown Hart Field April 23 and October 24, and Elkins Randolph County Airport May 5 and October 12.

That is about 193 frost-free days at Charleston, 184 at Morgantown and 160 at Elkins (our arithmetic), so a September seeding in the highlands around Elkins lands about two weeks closer to the first frost than in the Kanawha valley. WVU says to feed in fall about the time of the first frost, before dormancy.

Spring

WVU’s spring feeding goes on in March and April, when the grass begins to green up: 0.5 to 1 pound of nitrogen per 1,000 square feet from a complete fertilizer containing nitrogen, phosphorus and potassium, with at least 30 percent slow-release nitrogen. This feeding encourages earlier and more vigorous growth. It says to submit a soil sample before fertilizing or liming.

Cool-season grasses are best aerated in early spring or fall, using a plug aerator that pulls cores rather than a spike aerator that compacts the soil around the holes, and only when the soil is moist. WVU suggests a mowing height of 3 inches for cool-season grass to promote root development, lowering a new bluegrass lawn to 2.5 inches after five or six mowings.

Summer

The summer feeding is 0.5 pound of slow-release nitrogen per 1,000 square feet in June or July. WVU says it helps maintain growth and vigor and limits disease. Its lawn-problem guide warns against over-fertilizing to push fast, lush growth, especially in hot, humid weather, and says fertilizer can burn grass that is wet when it is applied.

WVU does not publish a weekly water amount for established lawns on the pages I opened. For new lawns it says to keep the seedbed damp and never let it dry completely once germination starts, with shallow, frequent watering because seedling roots stay near the surface, and no evening watering to reduce disease.

Fall

WVU says seeds can go down almost any time of year but names early to mid September as optimal for cool-season grasses and late spring or early summer for warm-season ones. Seeding rates are 1 to 2 pounds of Kentucky bluegrass, 4 to 8 pounds of tall fescue or perennial ryegrass and 3 to 5 pounds of thin fescues per 1,000 square feet. Mulching with straw holds moisture but can delay germination and favor fungus.

The fall feeding of 1 to 1.25 pounds of nitrogen per 1,000 square feet, from a complete fertilizer with at least 20 percent slow-release nitrogen, goes on before dormancy or about the first frost, in October and November. WVU calls it very important for winter root growth, disease and drought resistance and earlier spring green-up. Mowing continues in fall until the grass stops growing.

Fertilizer rules and soil tests

West Virginia’s Fertilizer Law is Article 15 of Chapter 19 of the state code. Its sections cover registration, labels, inspection fees, tonnage reports, misbranding and penalties, and section 19-15-16a prohibits local legislation. I found no section limiting phosphorus in home lawn fertilizer in the article’s table of contents.

WVU says most lawn grasses prefer a soil pH of about 6.5 and that West Virginia soils often range from pH 4 to 7, so established lawns may need lime periodically. Soil samples go to the county WVU Extension office. The lawn fertilizer calculator on this site converts each nitrogen target above into pounds of product for the bag you bought.