What are all the bumps in my lawn from? This is a question we often hear from our customers. Bumps in the lawn is often a sign of earthworm activity which is a good thing for you and your lawn. Earthworms tend to eat through the soil and eliminate behind themselves as they go. The eliminations are called castings. These little castings often look like small balls of soil. As the castings harden it often leaves tiny bumps in the soil. Night crawlers by far leave the biggest mound. You can usually find holes up to a ¼ inch after removing castings.
Having earthworms is great as they help to aerate your soil. This means they help greatly improve soil structure by releasing pressure in the soil. They also help to increase Microbial activity in the soil as well. Please remember worms are a good thing and any pesticides you use topically will not hurt them.
So how to handle the bumps? The best approach is not to try to hard to correct the issue at all. You will have earthworms forever and that is a good thing. But by fertilizing your lawn you will maintain a strong and healthy root system. If you can still see the mounds after fertilizing then it may also be a good idea to add top soil and over seed your lawn as well. Adding top soil will help smooth out the bumps and seeding will fill in thin or bare areas. One thing we do not recommend, is lawn rolling. Lawn rolling is bad because it condenses the soil and thus has the opposite effect as lawn aeration.