According to the Nutri-Lawn website (www.Nutri-Lawn.com), dew worms can be beneficial to the health of a lawn. Dew worms produce castings, or shedding, of their skin, which provides water penetration and aeration for the soil, as well as controls thatch buildup. According to the Northern Garden website, dew worms also provide nutrients to the bottom levels of the soil and create compost that can nourish any garden. However, dew worms can become a problem when their castings become unsightly and create a lumpy lawn.
According to the University of California’s Agriculture and Natural Resources website (www.ucanr.org), you could rake the dew worm’s castings manually or use a power rake with a thatch rake for more efficiency. Power-raking will cause the top layer of the soil to dry out and will inadvertently cause the dew worms to move to the lower levels of the soil. You could also mow the lawn at the higher end to hide the dew worm castings.
According to the Garden Guides website (www.GardenGuides.com), too much water or not enough water can greatly affect the number of dew worms on your lawn. For example, if you put too much water on your lawn, that can force the dew worms deeper into the soil. It may take several hours before the first few layers of the lawn are deeply penetrated with water.
The worms will also go deeper into the soil if the top layer doesn’t have enough water. For example, if you don’t water your lawn for a few days, this will cause the dew worms to travel to the lower levels of the soil to get water.
According to the Oxford Croquet website (www.OxfordCroquet.com), there are products that you can buy at a lawn store that will decrease the acidity of your soil and cause the dew worms to leave your lawn. Dew worms usually thrive in high-acidity soils. The acidic product should be reapplied about three weeks later. While this may cause the worms to leave your lawn or to move into the lower levels of the soil, the acidic agent could damage the overall health of your lawn. Grass usually has a preferred pH level to maintain its viability. If changes are severe to the pH levels of the grass, this could cause problems with grass growth or its ability to stay naturally healthy.