Most deteriorated lawns have a built-up layer of dead and partially rotted grass stems, roots and rhizomes just below the green grass leaves. This is known as thatch, and it must be removed before reseeding so water and fertilizer can reach the new seed. For small lawns, you can remove thatch with a garden rake. For large areas, go over the lawn with a power dethatcher, also known as a vertical mower or power rake. These machines can be rented from garden centers. Remove the clumps of matter left by the machine with a garden rake and level the soil by raking it.
If you have had a dry summer with below-normal rainfall, you need to replenish soil moisture before preparing a seedbed. Give the entire lawn a thorough watering, soaking until water has penetrated to a depth of at least 6 inches, then allow the surface to dry for a day or two before starting soil preparation.
If you are faced with a neglected lawn that’s partially dead and is being taken over by weeds, you may be able to renovate it. Restoring a deteriorated lawn may be possible if the weeds and dead spots cover less than 40 percent of the lawn area. Renovation of a weedy lawn involves more than just mowing down the weeds and throwing some grass seed over the lawn.
Water the Site
The best time for lawn renovation throughout the U.S. is mid-August to mid-September. Most weeds have not yet dropped their seeds and there will be little new weed growth. Also, reseeding at this time will give the new grass a chance to establish itself before going dormant for winter. Get rid of the weeds by manually pulling up large, spreading weeds. Follow up by applying a selective herbicide product that kills common broadleaf lawn weeds while not harming grass. For tough grassy weeds, like quack grass or crabgrass, use a nonselective herbicide such as glyphosate on the spots where these weeds have established themselves. Normally, all weeds will be dead within two weeks. Apply another herbicide dose in three weeks to get newly sprouted weeds.
The soil nutrients most important to healthy grass plants are nitrogen, potassium and phosphorous. Supply these nutrients by applying a commercial fertilizer formulated for starting lawns and lightly rake it into the soil before you reseed. Buy a grass-seed blend suited to your climate and local conditions and spread it over the lawn with a drop spreader or rotary spreader. Absent a different recommendation from the grass-seed grower, spread the seed at a rate of 2 pounds per 1,000 square feet on a lawn with substantial plots of live grass and 3 pounds per 1,000 square feet on bare soil. Water lightly once or twice a day to keep soil moist but not sopping wet. Don’t mow until the new grass gets 3.5 inches tall.
Herb Kirchhoff has more than three decades of hands-on experience as an avid garden hobbyist and home handyman. Since retiring from the news business in 2008, Kirchhoff takes care of a 12-acre rural Michigan lakefront property and applies his experience to his vegetable and flower gardens and home repair and renovation projects.
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This article was co-authored by Lauren Kurtz. Lauren Kurtz is a Naturalist and Horticultural Specialist. Lauren has worked for Aurora, Colorado managing the Water-Wise Garden at Aurora Municipal Center for the Water Conservation Department. She earned a BA in Environmental and Sustainability Studies from Western Michigan University in 2014.
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A patchy and weedy lawn is unpleasant and unappealing. Luckily, there are ways you can get rid of the weeds and replant grass seed to have a lush lawn. Before you start, it’s important that you purchase the right type of seed for your environment and you test your lawn so you know which kind of amendments and compost to use. If your lawn is really spotty and full of weeds, you should kill all of the weeds and old grass in your lawn and start over. If you only have a few weeds, you can spot weed and reseed.
Aeration improves your grassroots’ access to air, nutrients, and water. Use a spike or core aerator to break up the soil. If you use a core aerator, be sure to make two to three passes in different directions. Allow the plugs of soil you remove to decompose on top of your soil layer rather than remove them.
Once your lawn is nice and green, we recommend hiring a professional lawn care company to help you maintain it to keep it weed-free. Our top recommendation goes to industry leader TruGreen.
Step 3: Apply the Treatment
You have a choice ahead of you. Do you want to lay down seed or sod? There are pros and cons to each.
Next, it’s time to select the proper weed treatment based on both weed classification and the stage in their life cycle. Pre-emergent herbicides tackle weed issues before they spring up. Post-emergent herbicides target established weeds.
To seed your lawn, lay down approximately 1 inch of topsoil, then use a spreader to apply the seed to the soil.