Earthworms

The earthworm lives in the upper 300mm of the soil and is beneficial.

Soil without earthworm activity is unhealthy. The worm itself can vary from 6-200mm long, and is generally brown to reddish-brown in colour. Earthworms are one of the best methods of cultivating and improving soil. They "eat" soil and thatch in the turf. As these materials pass through the worm, they are mixed and digested.

The worm then excretes the soil mixture behind itself. In most cases this happens in the soil, but during the night hours when the turf is cool and wet, the worms are active on the turf surface. In the morning you may see evidence that the worms were active on the turf.

Castings, or small piles of soil, will be scattered about on the turf. A casting is the soil and thatch that the worm ate the night before. It is beneficial. A healthy turf has lots of worm activity. The worms are valuable to both the soil and turf. You should not try to kill them.

Earthworms come to the surface to breed, eat, hatch and breathe when the soil is too wet. When they are on the surface they leave muddy castings.

To avoid and cure the problem:

• Maintain proper mowing, and always remove the clippings
• Try to increase the acidity of the the turf by dressing it with lawn sand.
• Do not let your lawn get soggy.
• Let the muddy castings dry, and brush them back into the turf.
• Give the turf time to grow and mask the worm castings.

Apply chemical pesticides to discourage worms from surfacing. Only use chemical pesticides as the last resort, to kill or discourage worms from coming to the turf surface. Likewise, if you use a garden hose to wash the castings back into the turf, you may actually force even more worms to the surface, because they cannot breathe in wet soil.

Earthworms are a little messy, but they are beneficial for your turf and make great food for birds.

DID YOU KNOW

• There are 25 species of earthworms.
• 3 major species are associated with forming worm casts in the UK.
• 40-50 tonnes of soil per hectacre is brought to the surface by worm casts each year.
• Although worm activity is beneficial to the soil, very high populations may encourage moles.