There is a misconception that you should rake up grass clippings after you mow your lawn. People think that the grass clippings would add to the thatch that forms when you have dead plant life. Thatch is a layer of dead plant tissues that accumulate on the surface of your lawn. When left alone, thatch becomes too thick, which is enough to prevent airflow into the soil and may even deprive your grass of essential nutrients. However, thatch is made up of dead roots and stems, not the grass clippings. The cut blades of grass become fertilizer for your lawn. The top part of grass leaves are where the nutrients and water are stored, so it makes sense to leave them on your lawn after you're done mowing. This situation is especially true if you don't want to use grass clippings for your compost. What's more, if you're using a powerful mower, these machines can cut down grass clippings and twigs into mulch, which will further benefit your lawn. But there is one caveat: don't leave longer blades of grass on your lawn because they can invite lawn pests, which like shady areas. If you want to keep the grass short, consider mowing your lawn twice, each time cutting the grass shorter and shorter. Leaving the grass clipping on your lawn is called grasscycling, and this video shows you how to do it.