Seeding your lawn is more cost-effective than inserting grass sprigs or laying down sheets of mature sod. Seeding also takes longer to get the lawn established, and the nature of grass seeds means gardeners must take extra precautions to protect the seeds to ensure a thick and vigorous future turf. Several management strategies can help the gardener maximize his success with starting a new lawn from seed.
Time the Sowing
Gardeners should sow lawn seed during the late summer or early fall. During this time, cool nights and warm days make the ideal environment for seed germination.
Mulch has many benefits for a newly seeded lawn. First, it protects new grass seed from being blown away or eaten by birds. Second, it shields the soil and seeds from being washed away when the area is watered. Finally, it conserves soil moisture and helps keep seeds and seedlings consistently hydrated. Gardeners should only apply a light layer of mulch so that 50 percent of the underlying soil is still visible. Too much mulch and the underlying grass seedlings will be smothered.
Failing to correctly water a newly seeded lawn is an easy way to kill off grass seedlings. The soil should never be allowed to dry out or the fragile seedlings will whither and seeds will not germinate. Gardeners must keep the top inch of soil moist all day. Depending on the regional climate, this may require four or five watering sessions per day. Once the grass is an inch tall, the amount of water should be increased to provide a deeper level of moisture to a depth of four to six inches. This encourages deep root development.
It can take up to two months for a newly seeded lawn to grow tall enough for mowing, according to the University of California. The first time the gardener mows, the grass should be trimmed to 150 percent of the maximum height recommended for the specific turfgrass species (see Resources). For example, St. Augustinegrass is typically cut at 2 inches. The first time its mowed, it should only be trimmed to 3 inches. This gives the grass time to establish itself fully. Wait four to five days before mowing again, this time trimming the grass down to its recommended height.
Fertilization helps boost lawn seed germination rates and helps the new seedlings develop appropriately, according to Purdue University. Gardeners should apply a lawn starter fertilizer on the seeded area at the rate listed on its label. Purdue University recommends any starter product that's high in phosphorous, such as one with a 16-22-8 nutrient ratio.