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can you seed grass over weeds

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.

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.

Water the Site

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.

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.

Creating a lush, vibrant lawn takes commitment, but the rewards of a successful grass seed project are worth the time and resources you invest. A beautiful lawn can improve your home’s value, benefit the environment and enhance your family’s quality of life. Even if you’re a first-time lawn grower, you can seed right and avoid these common mistakes:

Using the proper amount of seed for your project influences success, whether you’re starting from scratch or overseeding an existing lawn. New lawns or spot repairs take about twice the amount of seed needed for overseeding thin areas. Quality grass seed labels include guidance on optimal seeding rates to maximize your results.

1. Planting the wrong type of seed

Getting your seeding rates right requires knowing the correct size of the area you need to cover. One of the most common problems grass professionals see is when homeowners misjudge their actual lawn areas and over-apply grass seed or other products, such as fertilizers and herbicides.

It can be tempting to plant seed as soon as the need arises. But proper timing has an important impact on results. Grass growth occurs in seasonal cycles, which vary according to the grass types common to different regions. Timing your seed projects to coincide with growing cycles greatly improves your rate of success.

Don’t overdo or cut corners. Too much grass seed causes undue competition for resources such as light, water and nutrients, and grass seedlings struggle as a result. Too little seed leaves lawns thin or bare. Always follow “best practice” guidelines for planting grass seed, including site preparation and good seed-to-soil contact, and stick with recommended seeding rates for lush results.