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when to weed and seed lawn

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 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.

Kill the Weeds

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 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.

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.

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.

One of the ways weed treatments work is by preventing germinating seeds from establishing roots. But these products, known as pre-emergents, can’t distinguish between harmful weed seeds and desirable grass seed you put down. Using these products too close to newly planted seed — in timing or proximity — stops grass seed in its tracks, along with the weeds. Post-emergent weed treatments aimed at existing broadleaf weeds can also injure immature grass seedlings.

When soil test results show your lawn’s soil pH is below levels needed for optimal grass health, liming in accordance with recommendations restores proper pH balance, increases nutrient availability and helps keep lawns green. While many lime products are slow to work, products such as Pennington Fast Acting Lime speed up the process and start working immediately.

4. Ignoring recommended seeding rates

Without knowing where your soil stands, well-intended soil amendments and fertilizers can harm grass instead of help — or simply go to waste. Incorporating your specific soil lab recommendations helps circumvent potential problems and unnecessary setbacks. That’s one reason turf professionals emphasize regular soil testing to start seed right and keep lawns healthy and vibrant. Your local county extension office can help with testing kits and lab referrals.

Even with similar seed types, all grass seed isn’t equal. Learn what’s actually inside the seed bags you or your lawn professional buy. By understanding the seed tags on grass seed products, you can be sure you invest in quality seed. Cheaper price tags can mean less seed versus fillers, old seeds past their prime, more weed seeds and lower germination rates. Getting seed right from the start benefits your lawn and budget.

For most of the country, fall is the best time to plant grass seed. This is when cool-season grasses such as Kentucky bluegrass and tall fescues peak in growth, and conditions enhance fast germination and establishment. When paired with innovations such as water-conserving Pennington Smart Seed, proper timing leads to other advantages, including less input of resources, less maintenance and better results.

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: