Why Is Some of My Grass Seed Not Growing?

Thick Thatch

• Grass seed cannot establish on thick thatch. A thick layer of thatch over 1/2 inch creates a barrier between seeds and the soil. Seeds must penetrate the thatch layer in order to establish root systems. Also, a thick thatch layer can dry out soil which makes germination difficult. Check your thatch layer before seeding by cutting out a 2-inch, wedge-shaped piece of turf. If the thatch layer is over 1/2 inch, dethatch the lawn with a power dethatcher. You can rake up small ares of thick thatch to reseed, but the rest of the lawn will have problems if it suffers from a thick thatch layer.

Starter Fertilizer

• Starter fertilizer should be supplied to lawns in order to provide enough nutrients for grass seed. Grass seed needs a fertilizer that is high in phosphorous to establish strong root systems. A starter fertilizer with a NPK amount of 5-10-5 should be applied to lawns before seeding, as recommended by the University of California. If seeds are not growing in certain areas, you can dig up the small seedlings and till in the fertilizer prior to reseeding the lawn. Avoid using excessive nitrogen or you could burn up the grass seeds.

Water

• Grass seed will dry out on improperly watered soil. Soil must be kept moist until seedlings emerge. Because you don't want to spray the seeds off the lawn, apply a light spray of water several times a day to keep the first inch of top soil moist, as recommended by Lance Walheim from the National Gardening Association. Examine the soil for discoloration. If you notice two-thirds of the soil surface being lighter in color, it means it's dry and needs to be watered.

Sunlight

• Grass seed will experience difficulty if planted in an area that receives less than four hours of sunlight a day, according to Clemson University. Gardeners who have overhanging trees casting light can prune back their branches to add more light to the yard. Remove shrubs or large structures that cast too much light. Avoid planting a grass type that needs a lot of sun, such as Bermuda grass, in areas that receive less than eight hours of sunlight a day.