Planting grass seed to repair patches in your lawn requires careful planning for success. Healthy grass extends deep roots into the soil. Grass will grow strong and thick with adequate soil preparation and proper watering before and after planting seed. Strong roots also help limit the spread of nuisance weeds. The steps for planting grass seed in a small patch or larger lawn area are identical. The key to successfully planting grass seed lies in allowing the seed to rest in good soil with adequate water.
Set up the sprinkler attached to a garden hose and water the area for an hour. Make sure to lightly soak areas requiring patches or full seeding. Watch the soil for pooling water or runoff and stop the sprinkler if this occurs. Allow the water to soak into the soil and then turn the sprinkler back on to finish watering.
Gauge the depth of moisture in your soil by digging with a trowel to a depth of 6 inches. Remove a clump of dirt and squeeze it in your palm. If the soil holds a rounded shape, the soil has plenty of moisture. Crumbling soil requires additional watering. Waterlogged soil will have difficulty forming a rounded shape and will seep through your fingers.
Repeat the watering process until your soil test shows even moisture to a depth of at least 6 inches.
Rake patches you want to seed to remove dried, dead grasses and any weeds. Before seeding a new lawn, remove clumps of weeds and rocks and smooth the area to a level surface.
Apply a 1-inch layer of topsoil to patch areas. Spread this topsoil evenly, blending it into the existing grass. Topsoil should be applied more thickly to a depth of at least 6 inches to a new lawn. Always use weed-free, high-quality topsoil for lawn applications.
Repeat the deep watering process to allow the new topsoil to absorb water. Look for areas with runoff or pooling and level these areas. Don't saturate the soil completely; instead, aim for uniform moisture throughout the seeding area.
Fill the spreader and dispense the grass seed over the required area. Make multiple passes with the spreader to ensure uniform distribution of the seed.
Cover the seed with a 1/4- to 1/2-inch-deep layer of topsoil. Soil must come in contact with the seed as part of the germination process. Firm the soil by hand for smaller areas or use a drum roller for larger seeding areas.
Water the lawn regularly over the next few weeks to prevent the soil from drying out. Contact with moist soil will encourage germination of the grass seeds. Back off on the frequency of watering when the grass reaches 2 inches in height.