Rake after grass dries out but before weed seeds start to germinate in earnest. Organic fertilizers are best applied in late summer - early fall but may also by used in the early spring. Compost and grass clippings can be applied throughout the growing season. This increases air and water circulation. Rent a mechanical aerator or hire an organic lawn care company to do the work for you.
Manual aerators are well suited for small to mid-sized lawns.
This adds nutrients and microorganisms to your lawn. 11 Overseed Grass plants, like all living things, eventually die. This is why overseeding every year in spring or late-summer is a good idea. Introduce hardy, pest-resistant grass species such as endophytic perennial ryes and fine fescues into your lawn. Allow seeds time to germinate in cool, moist conditions and the grass to become well-established prior to the hot, dry weather of summer.