Lawn Problems & Worm Castings

Castings

• Worm castings are actually the manure that worms excrete from their bodies. The castings are considered valuable for adding to plants as a ready, organic source of nutrients and beneficial microbes. Castings are a sign that there are worms digging through the soil, mixing minerals and organic matter and making tunnels that aerate plants' roots. A lot of worms in an area is an indication that the soil is in good condition. Castings can also be produced in worm composting bins and added to the lawn in the same way compost or fertilizer would be.

Lumpy Lawns

• Lawns that have an active, plentiful population of worms, particularly night crawlers, may have a problem with many small lumps scattered across the area. These lumps are actually small piles of earthworm castings and are the result of the worms feeding on clippings, thatch and other organic material on the surface, then burrowing into the soil, leaving the castings behind. The Colorado State University Extension Service recommends that these piles be rolled into the soil with a weighted roller twice a year, preferably after the soil has been aerated. This will help to smooth the lawn without harming the beneficial worms.

Benefits

• A population of worms in a lawn benefits the soil in a number of ways. Their tunneling aerates the soil. This helps to trap water, reducing runoff and preventing the soil from drying out too quickly. They dig and turn the soil, bringing the humus from the top to under the ground, making the nutrients more readily available to the plants. As they eat the humus, leaf litter and grass clippings, the worms typically excrete castings in the layer of soil just below the surface. This puts it right where the lawn needs it. Building a population of worms in a lawn and providing adequate food for them in the form of grass clippings or mulch can help a lawn regain color and vigor without the need to resort to harsh chemicals.

Fun Facts

• Earthworms can eat their weight in food every day. They have no eyes, arms or legs, and if they dry out, they will die. Worms are hermaphrodites, meaning that every worm is both a male and a female, but it still takes two worms to reproduce. The largest worm ever found was 22 feet long and was discovered in Africa. There can be more than 1 million worms in a single acre of land.