Should I Dethatch Before Overseeding?
Dethatching before overseeding is usually helpful only when the thatch layer is thicker than about half an inch and the lawn is otherwise healthy enough to recover. It can improve seed-to-soil contact and water penetration, but it also stresses existing turf and may expose weed seeds. If thatch is thin, alternatives such as core aeration or light raking are often the safer choice. Match the timing to your grass type and be prepared to water and fertilize afterward.