Can You Grow Grass on Top of Grass?

When to Overseed

• When lawn areas look generally healthy but are thin or bare in certain areas, it may be time to overseed. Overseeding is most successfully done in the fall. In most parts of the country September is a good month for seeding and overseeding of lawn areas. Weed competition is less in the fall as are stress-inducing high temperatures that can negatively impact young, first-year seedlings in the summer. Root development can continue late into the fall even when the above-ground grass is dormant.

Site Preparation

• Successful overseeding is predicated upon proper site preparation of the lawn areas to be treated. Make sure that the surface of the soil has been overturned or otherwise "roughed up" to create the appropriate medium for seed germination. Mow the surrounding grass short prior to overseeding and rake away any debris. Use a hand rake, power rake, dethatcher or core aerator to loosen the top 1 to 2 inches of soil.

How to Overseed

• Overseeding can be accomplished by a variety of methods. For very small areas, grass seed can be applied by hand as evenly as possible. For medium-sized areas, use a hand-held spreader. For larger areas or sites with multiple areas, use a walk-behind spreader. Rates for usage and spreader settings are printed on the packaging of most commercially available bags of grass seed and also in the literature accompanying most spreader models.

Maintenance

• Grass seed roots germinate in the top 1 to 2 inches of soil. Keep overseeded areas moist after the application with light, frequent waterings. Newly seeded or overseeded lawn areas often need to be watered once per day while establishing. Keep the surrounding lawn areas mowed to reduce competition while the new seedling are germinating. After approximately six weeks, the overseeded areas should receive a fertilizer application of 1 lb. of actual nitrogen per 1,000 square feet of lawn area.