There's a secret behind achieving a beautiful, lush lawn. Landscape professionals know what it is, but many homeowners don't. Overseeding — as part of a comprehensive, proactive plan — keeps lawns looking great. Whether you're tending your lawn for the first time or have years of experience, overseeding can improve your results.
Overseeding is simply spreading grass seed over an existing lawn. Done right, it's a straightforward process that gets the most from your seed and labor. As grasses mature, thinning is normal — especially if you enjoy your lawn and use if often. Overseeding keeps your lawn competitive and steeped in youth and vigor, without starting over from scratch.
The basics of overseeding are the same everywhere, but goals and timing vary based on geography and the type of grass grown. For success with overseeding your lawn, follow this basic guide:
- Establish your goal. Homeowners overseed to correct thin lawns, but pros overseed to prevent thinning. For lawns in southern regions, overseeding warm-season grass with cool-season reinforcements adds green color during winter. When warm-season grasses go brown, overseeding with a premium, cool-season grass mix, such as a Pennington Perennial Ryegrass, keeps them vibrant and green. This combination of cool-season grasses, stabilized fertilizer and mulch provides a green temporary lawn while your permanent, warm-season grasses are dormant.
- Time the task. Prime time for overseeding cool-season grasses in northern regions is late summer to early fall. Spring is the second best time. Cool-season grasses grow most vigorously during these times of year. Tough, warm-season weeds, such as nutsedge and crabgrass, are less active in fall. Warm soil encourages germination, cool fall air stimulates growth, and soil moisture fluctuates less. The Turfgrass Water Conservation Alliance service recommends overseeding at least 45 days before your average first fall frost.1 In southern areas, overseed thinning lawns in late spring, as warm-season grasses enter their active growing season. For winter color, overseed lawns in fall. Wait until nighttime temperatures drop consistently below 65°F and your existing warm-season lawn slows and begins to lose color.
- Prepare the area. Mow your lawn extra short and remove the clippings, so new seed contacts soil and gets sunlight and water. Set your mower at two inches or less for regular overseeding. For southern lawns and winter color, set the blade as low as it goes, and cut just above the soil – what's known as scalping. Rake the soil with a metal thatch rake to remove clippings, thatch and debris. This loosens and exposes soil to receive seed.
- Correct existing problems. For troubles beyond normal thinning, test your soil and make corrections before overseeding. Follow test recommendations for soil amendments, and repair bare lawn spots. If needed, take time to dethatch and core aerate compacted lawns, so air, moisture and seed can get to soil. Pennington New & Improved One Step Complete. products combine premium seed with a stabilized-release fertilizer and wood mulch to simplify lawn repairs.
- Select a quality grass seed product. Better seed yields better lawns. Always use grasses recommended for your regional climate and top-quality seed you can depend on. Pennington Smart Seed. grass seed products provide premium grass seed appropriate for sun, shade or high-traffic areas in lawns in northern or southern regions.
- Spread your seed. Apply seed at label-recommended overseeding rates, using the spreader that suits the job. Use drop or broadcast spreaders for large lawns and handheld spreaders for smaller areas. For small spots, simply seed from your hand. Work when air is calm, so seed distributes evenly.
- Fertilize overseeded areas. Avoid weed & feed products; the pre-emergents inhibit seed germination. Starter fertilizer, such as Pennington Ultragreen Starter Fertilizer 12-22-8, delivers essential nutrients for new grass. Phosphorus supports vigorous root growth, while nitrogen fuels top growth and greening. Some states and counties restrict phosphorus lawn fertilizers due to environmental concerns regarding runoff. Exceptions may be made for new seedings. Check with your local county extension agent about nutrient application restrictions.
- Keep your lawn well-watered.Newly overseeded lawns need consistent moisture. Keep seed and soil moist with frequent, light waterings twice a day for the first four days. Water more heavily every other day for the next five days. Then water as needed to prevent wilting. This encourages deep, healthy roots.
- Return to regular maintenance. Keep your newly revived lawn looking its best with a regular, comprehensive maintenance plan that includes diligent watering, mowing and proactive overseeding. A simple weekday maintenance schedule can keep your lawn lush and your weekends free.
For the lawn of your dreams, don't wait to overseed until your lawn looks less than its best. The full line of Pennington grass seed and lawn repair products and Pennington lawn fertilizers and soil supplements can help you keep your lawn at its peak.
Pennington, One Step Complete, Smart Seed, and Ultragreen are trademarks of Pennington Seed, Inc. Turfgrass Water Conservation Alliance is a registered trademark of NexGen Turf Research, LLC.
1. Turfgrass Water Conservation Alliance ; "Simple Tips," October 2014