Improve poor lawns
1. Aerate to improve root development.
Aerating your lawn in the spring or fall will improve root development and water penetration. Aeration removes little plugs of sod and dirt from the lawn and allows air under the lawn. You can rent an aerator, or get a yard service to aerate for you.
2. Overseed thin areas.
Overseed, after raking or aerating to expose soil, with a perennial rye/fine fescue mix designed for Pacific Northwest conditions. Talk to a knowledgeable nursery-person or contact Cooperative Extension for seed recommendations. A light application of "starter" fertilizer can help the seeds grow quickly and crowd out weeds.
3. Top dress to with compost.
Rake in 1/4 to 1/2 inch of compost to cover the seed and improve the soil.
4. Mulch mow, once new grass has been established, use a mulch mower to leave clippings on the lawn where they will provide an immediate benefit.
A mulch mower Download PDF chops up clippings into tiny bits and blows them into the lawn where the moisture from them feeds and waters the lawn each time you mow.
5. Repeat annually.
Repeat these steps annually, as needed, and your lawn will be dense and healthy.