Summer 2022 has been very hard on many local fescue lawns. Brown patch fungus and an August with very little rain has resulted in the need for overseeding for many homeowners. September is near and this is the best month to overseed and repair a fescue lawn. Here are some tips that will help.
Prepare the soil
Establishing good seed to soil contact is essential for good germination rates. Verticutters/slit seeders achieve good contact at the time of seeding by dropping seed directly behind the blade that slices a furrow into the soil. The same result can be accomplished by using a verticutter before broadcasting the seed, and then verticutting in a different direction a second time.
Core aerators can also be used to seed grass. Go over an area at least three times in different directions, and then broadcast the seed. Germination will occur in the aeration holes. Because those holes hold moisture longer than a traditional seedbed, this method requires less watering.
Tall fescue seed blends are the best choice for cool season turf in our area. Mixes or blends containing several newer tall fescue varieties allow you to take advantage of differing strengths of each variety. Good seed costs a little more but is usually worth it since it contains far fewer weed seeds in the mix. Avoid seed mixes containing other seed types- such as perennial ryegrass.
Overseed the lawn
Here is a short list of steps to follow:
• Mow the lawn short, to 1.5-inch height.
• Water the lawn if necessary to make it easier to prepare soil (especially if you plan to aerate)
• Core aerate or verticut the lawn to allow good seed to soil contact. Don’t forget to flag sprinkler heads to avoid damage to an irrigation system. For small areas you can simply use a rake to rough up the soil to create a seedbed.
• Sow seed uniformly. Use 6 to 8 pounds per 1,000 square feet if repairing large, killed-out areas. Use half-rate (3 to 4 pounds per 1,000 square feet) if trying to thicken a thin lawn or for seeding in shady areas. Note that using too much seed can create future problems with competition, stress, and disease.
• Fertilize with 1 pound nitrogen per 1,000 square feet or apply a lawn starter fertilizer.
• Water in the seed and fertilizer.
• Once seed sprouts, try to minimize traffic (foot, mower, dog, etc.) seeded areas receive until the seedlings are a little more robust and ready to be mowed.
•Begin mowing once seedlings reach 3 to 4 inches tall
• Do not use broadleaf weed killers for one month before seeding, or after seeding until the new grass has been mowed three times.
• Do not use crabgrass preventers before seeding or after seeding until the new grass seedlings are well established
Keep seed moist
Remember, grass seed can’t germinate without moisture and this is where many new lawns fail. Newly germinated grass seedlings die quickly if they dry out. So, after you’ve finished planting, soak the seed bed to a depth of several inches. Then keep the seed bed moist with frequent, light sprinklings—so you don’t disturb the seeds or young growth. You may have to water gently several times a day if the weather gets warm or windy. Let the plants tell you when to water. If you can push the blades down and they don’t spring back up quickly, the lawn needs water. Wean the lawn from supplemental water by progressively watering less frequently after full germination and as the plants mature.