Dethatching is the process of thinning out this layer so that your lawn can breathe a little easier. Good news: Unlike mowing, dethatching generally only needs to be done once per year. Pros also generally recommend avoiding dethatching during a heat wave, drought, or in any other weather that might have your lawn feeling stressed. Add to Google settingsHow to dethatch the lawnFor small lawns, our experts in the Home Improvement & Outdoor Lab at the Good Housekeeping Institute recommend a dethatching rake. How to prevent thatch from coming backTo prevent too much thatch from forming on your lawn, avoid overwatering, as this will impede the breakdown of organic material.