How to Plant Grass Seed

Planting grass seed is an economical and satisfying way to expand the green space around your home or improve your existing lawn. In order to enjoy successful grass establishment and all the benefits seeding offers, follow these eight steps to grow a lush, inviting green lawn:

1. Choose the Right Time of Year
2. Prepare the Site
3. Prepare the Soil
4. Choose the Best Seed
5. Plant the Seed
6. Water Appropriately
7. Monitor Seed Establishment
8. Mow and Maintain

Choose the Right Time of Year

The time of year you plant grass seed has a direct effect on its success. Proper timing helps ensure your grass seed will germinate properly, grow quickly and remain healthy while new seedlings become established.

The best time to plant grass seed varies according to your grass growing region and the type of grass you grow. Lawns across the northern tier of the United States typically consist of cool-season grasses, such as Kentucky bluegrass, tall fescue or perennial ryegrass. Planting during cool weather in fall and spring coincides with the most active growth periods for these grass types.

In Massachusetts, for example, early fall is the ideal time to plant grass seed.¹ At this time, the ground is still warm enough to aid germination, but the days are cool and sometimes rainy. This combination helps ensure newly planted seeds don't dry out. There's also sufficient daylight in early fall to allow new grass to thrive and become established before winter's arrival.

Spring seeding is your second best option for planting cool-season grasses. Aim to seed early in the season, but wait until daytime temperatures are in the 60 to 75 degree Fahrenheit range. This roughly corresponds to the optimal soil temperatures for cool-season grass seed germination. Spring sunshine and rain both contribute to strong grass growth.

For lawns across the southern half of the U.S., warm-season lawn grasses such as Bermudagrass, Zoysia grass, Bahiagrass and Centipede grass are the rule. These grasses are best planted during their optimal growth period, which falls in spring and early summer instead of fall. Wait to plant warm-season grasses until daytime temperatures stay near 80 F or higher and all danger of a late spring frost in your area has passed.

Prepare the Site

A healthy, attractive lawn starts with proper site preparation. Proper grading of the site prior to planting is important, as it helps ensure water drains away efficiently and allows for easy mowing. Sloping the lawn area away from buildings at a rate of 1 to 2 percent is recommended.² Avoid creating steeper slopes, as they tend to cause lawns to dry out too quickly. Smooth the site well to avoid depressions, which can create wet spots that are hard to mow and prone to disease.

If you intend to replace the entire lawn, it's important to do a thorough job of removing the old turf. Use a sod cutter to take out the old grass at the roots. Another option for clearing the area is to spray the lawn with a non-selective herbicide such as KnockOut Weed & Grass Killer II Ready To Use, which kills both grass and broadleaf plants

After the product's designated waiting period, reapply as needed to kill any remaining grass. Once you're certain that the turf you want to replace is dead, clear the dead grass from the site and make any needed adjustments to the grade to prepare for seeding.

Prepare the Soil

Optimum soil conditions boost successful seed germination and support healthy turf growth. To prepare your soil for planting, do the following:

• Test your lawn's soil. Proper soil pH is critical to a healthy, thriving lawn. Most lawn grasses do best when soil pH is between 6.0 to 7.5.⁴ Taking accurate soil samples is simple to do on your own, but you'll need to send those samples to a reputable soil laboratory for testing. Your local county extension office can help with soil testing kits and information about testing facilities. The test results will give you an accurate picture of the state of your soil's pH and nutrient levels, plus recommendations for changes you should make.
• Amend to alter soil pH. If your soil test shows that your lawn's pH is outside the range for healthy turf growth, soil amendments can restore pH balance. Soil with overly high pH, called alkaline soil, is common in the West. Applications of elemental sulfur may be recommended to correct it. In areas where soil is acidic, having overly low pH, your lawn may need lime to restore nutrient availability. This is often the case in the Northwest, Northeast and Southeast. Always follow your soil test recommendations and product label instructions carefully.
• Add nutrients to soil. The recommendations from your lawn soil test will outline your soil's nutrient needs. A high-quality lawn fertilizer, such as a premium Pennington fertilizer for lawns, can help restore optimal nutrient levels for healthy grass growth. Recommendations may include a phosphorus-containing lawn starter fertilizer.⁴ However, some states have environmental restrictions on phosphorus fertilizers, so check with your local extension agent on your state's lawn fertilizer requirements.
• Amend to alter structure. Conditions such as very sandy soil or heavy, compacted soil affect seed germination, growth and the overall health of your lawn. For healthy grass growth, soil needs to contain sufficient air, yet it also needs to retain the nutrients and moisture grass needs. Improve your new soil's aeration and water penetration by removing rocks and incorporating organic matter, such as compost, at a depth of 2 to 4 inches before planting. Local hardware or garden stores often rent tillers or aerators, which improve compacted soil by pulling out plugs of soil to allow for air and water.

Choose the Best Seed

To succeed at growing a healthy lawn, it's important to buy quality grass seed that is well-suited to your climate and your growing conditions. Premium, purebred Pennington Smart Seed grasses are water-conserving, drought-resistant and developed for superior performance in home lawns.

Whether you grow warm-season or cool-season grasses depends primarily on where you live. Warm-season lawn grasses are best suited to southern climates and grow most vigorously during the warm months of the year. They typically go dormant and brown in the winter. Cool-season grasses are typically used in northern and transition zone lawns, growing best where summers are moderate and winters are cold. They remain green all year, but can go brown and dormant in heat and drought.

In many areas of the country, you can opt for a mix of seed specific to your region. Smart Seed mixes are designed for lawns in the Midwest, Northeast, Pacific Northwest and Pennsylvania State. If you're growing lawn grass in shade, choose a grass seed product such as Pennington Smart Seed Dense Shade Grass Seed and Fertilizer Mix, which is formulated especially for challenging low-light conditions. 

Plant the Seed

Once amendments are complete and your soil surface is smooth and prepped, broadcast the seed evenly according to your seed product's recommended seeding rates. Remember to carefully review the seed package label instructions and follow the guidelines. Misapplication of seed can lead to unsatisfactory results.

Choosing the right type of spreader for your situation helps you get the results you need. A drop spreader drops seed straight down in a path the width of your spreader as you move across your lawn. This type of spreader maneuvers well in tight spaces and is ideal for small lawns (less than 5,000 sq. ft.), which typically require more precision in where the seed lands.

A broadcast or rotary spreader comes in walk-behind and hand-held types that spread seed by fanning it out in all directions, providing more uniform coverage. These spreaders are ideal for large lawns, but they lack the precision drop spreaders provide.

Once you finish spreading the seed, use a rake to lightly work it into the soil at a depth of about 1/4 inch. Don't bury the seeds any deeper; grass seed needs adequate light to germinate quickly. After raking, pass over the area with a roller, which helps ensure the good seed-to-soil contact your new seed needs.

Overseeding is the process of planting grass seed into an existing lawn. This is done to improve your lawn's overall look and health, thicken your grass, minimize weeds, fill in bare or damaged areas, or convert to another type of lawn grass. Also, southern lawns are often overseeded with a cool-season grass to provide green color during winter months. When overseeding, broadcast the seed over the lawn, and water it in well, following the same instructions as for new lawns.

Water Appropriately

Keeping grass seeds and seedlings constantly moist but not soggy is critical to successful grass-seeding efforts. Water newly seeded areas two to three times a day with a light spray to keep the seeds moist. Stop watering when puddles begin to appear on the soil surface. Once the seeds germinate and grass seedlings begin to grow, gradually transition to watering less frequently but more heavily. Taper off watering as the grass becomes taller and more mature.

Monitor Seed Establishment

Depending on the type of grass you're growing, germination may take anywhere from five to 21 days. Expect your new grass to take another four to 10 weeks to root well and become established. It will take a full season for most grasses to mature to the point where they're ready for steady foot traffic.

Once your new seedlings reach about 1 inch in height, examine the newly seeded area for any bare spots or places you may have missed. Reseed the bare areas, and repeat the process as needed until new seedlings are thick and you're satisfied with the results.

Mow and Maintain

Once your grass reaches 3 inches high, it's ready to withstand mowing. Always follow best practices for mowing lawns, including the recommended mowing heights for your type of grass. Never remove more than one-third of the grass blade in a single mowing or you can stress your grass and invite lawn disease, lawn weeds and weak growth. With fall-planted cool-season lawns, your first mowing may need to wait until the following spring.

During the first season of establishment, young grass is still tender, so avoid as much foot traffic as possible. Keep your grass growing strong with regular maintenance, including irrigation. Water as needed to supplement rainfall so your lawn receives about 1 inch of water per week under normal conditions.

Begin fertilizing cool-season lawns four to eight weeks after seed germination, but never later than November. For warm-season grasses, wait until the following spring to feed your new lawn. After initial feedings, you might need to fertilize up to four times a year, according to your soil test recommendations. Retest the soil every three to four years, and adjust accordingly.

Conclusion

By choosing the best grass for your region and your lawn's conditions — and following these simple guidelines — planting grass seed is a straightforward project that will transform for your yard. Pennington is dedicated to providing you with the resources and premium products you need to grow lush, beautiful turf. You and your family and friends can enjoy all the benefits of a beautiful, natural lawn.

Total Time Required to Transform Your Lawn: 6-12 weeks, depending on the region, weather and grass type.

How hard you'll have to work on a scale of 1-4: 3 (a little work goes a long way especially during the prep phase)

Time breakdown:

• Prep time: 3-8 hours, depending on lawn size and if you are replacing the lawn or overseeding (one weekend)
• Seeding: 2-4 hours, depending on lawn size and if you are replacing or overseeding
• Watering: 10 minutes a day {or more depending on sprinkler outputs} for 10-14 days; then tapering off until you are watering twice a week in the spring and summer
• Fertilizing: 1 hour three times a year {for cool season grasses} in the spring and fall, {up to four times a year for warm season grasses} depending on the grass variety {species}.

Pennington and Smart Seed are registered trademarks of Pennington Seed, Inc.

Sources:

1. University of Massachusetts Amherst, “Lawn Renovation and Overseeding."

2. Ricigliano, D., "Lawn Establishment, Renovation and Overseeding," University of Maryland Extension, 2016.

3. Nathan, M. and Fresenburg, B., "Soil Testing for Lawns," University of Missouri Extension, June 2008.

4. Grande, J., "Seeding Your Lawn," Rutgers New Jersey Agricultural Experiment Station, February 2004.