For overseeding an existing lawn:
•Mow grass as short as possible.
•Loosen the top ¼-inch of soil in bare spots.
•Remove debris and dead grass.
•Level the areas where excess water collects. Use existing topsoil; added soil may have weed seeds.
•Fertilize the bare spots after overseeding with a pre-seeding fertilizer.
Step 3 –Sow grass seed
•Spread the seed evenly by hand in small areas.
•Use a hand or lawn spreader or a mechanical seeder in large areas.
•Apply approximately 16 seeds per square inch. Too many seeds too close together causes seedlings to fight for room and nutrients. Grass may be weak or thin in these areas.
Step 4 – Cover Seeds
•Lightly drag the grass seed bed so no more than ¼-inch of soil covers the grass seed.
Step 5 – Water often
•Keep grass seed bed moist to enhance germination.
•Water lightly (don’t saturate), and frequently (at least once daily), until new grass is two inches high.
•Water new grass regularly to keep roots moist.
When to sow grass seed
Grass seed can be sown in the Spring and Autumn with good results. If you are planning a spring sowing of grass seed, do not apply weed control products to the grass. Delay the weed control application until the grass seed has germinated and you have mowed the grass at least 3 times.
For an Autumn sowing of grass seed, follow the same weed control precautions and time the seed sowing to allow the grass seed to fully germinate before freezing temperatures arrive.