Care of Cool-Season Lawns

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While mid-September to early October is considered the ideal time for establishing cool-season turfgrasses such as fescue and Kentucky bluegrass, there is still time to get your seed out if you hurry! Mid-October will still provide decent germination for establishing and reseeding your cool-season lawn. Young seedlings normally emerge and grow best when air temperatures are between 70 and 80 degrees. Soil temperatures need to be greater than 60 degrees for good germination. If you miss the opportunity this fall you can try again in March, however turfgrass mortality is increased due to the eventual onset of summer heat and humidity and lack of maturity.

Most of North Carolina is located within the transition zone. This means that we can grow both warm and cool-season grasses with relative ease. However, cool-season grasses such as fescue will tend to struggle some during prolonged summer heat and dry spells. Fescue growth will almost come to a complete halt during the summer months. This isn’t the same as warm-season grasses such as bermuda, zoysia, and centipede which turn brown after the first hard frost and freeze and go into dormancy. This means under the best of conditions fescue can “almost” provide a green lawn year-round.

For best results and to make the most of your investment, select cultivars recommended by NC State located on our Turffiles website. Cultivar names should be listed on the seed bag label. If you buy a tall fescue blend, try to find one with at least one of the cultivars from the list of recommended cultivars. These grasses were chosen because they produce a high-quality turf in North Carolina and have been shown to be less susceptible to brown patch disease. Some like to mix in a little Kentucky bluegrass (darker color and finer texture) or fine fescue (for shady areas). Do not add ryegrass to the mix.

Before seeding core aerification is recommended to reduce compacted areas. Getting good soil to seed contact is paramount to maximize available soil moisture. If you’re starting with bare ground then a light application of wheat straw on top of the seed will assist in moisture retention and soil to seed contact. A typical tall fescue seeding rate is five to six pounds of seed per 1000 square feet. Germination will normally be in five to ten days with soil moisture and suitable soil temperatures but can take as long as 21 days.

Since seeds and seedlings may be damaged by some herbicide applications, fall-seeded, cool-season grasses should not have any herbicides applied until after the first several mowings. The first mowing should be completed when fescue is 4.5 inches tall and mowed at a height of 3 inches. It is recommended to either continue this height or you can increase it to 3.5 inches.

Follow your soil test report for the most accurate application of lime and fertilizer. In the absence of a soil test, use a complete turf-grade fertilizer with a 4-1-2 ratio, such as 16-4-8. Apply one pound of actual nitrogen per 1000 square feet at seeding and, optionally again a month later. Keep newly planted areas moist with light irrigation. As these areas fill in, encourage deeper rooting by watering less frequently but for a longer duration. Deeper roots are more resilient and can lead to a healthier stand of grass that has fewer weeds and disease issues.

For more information on horticulture and other topics please contact the N.C. Cooperative Extension, Franklin County Center at 919-496-3344 or Colby Griffin, Commercial and Consumer Horticulture Extension Agent, at colby_griffin@ncsu.edu.