What do earthworms do?

Earthworms are a familiar sight to gardeners and are useful in maintaining healthy garden soils;

• Earthworms can be active throughout the year but are usually dormant (quiescent) during cold or hot and dry weather.
• Earthworms occur in most soils, but are scarce in soils that are extremely acidic or prone to water logging
• There is unusually no need to introduce earthworms as they are usually present at natural densities and will colonise new gardens
• Earthworms eat decaying plant material and do not damage growing plants. They are important to soil structure and fertility
• Some earthworms emerge at night to feed on dead plant material on the surface, and will pull fallen leaves and other plant debris into their tunnels
• Some species such as Allolobophora nocturnal, A. long and Lumbricus terrestris live in permanent burrows and it is mainly these species that produce worm casts on the surface

Find out more about earthworms and participate in earthworm research at Earthworm Watch and the Earthworm Society of Britain (links to external websites)

Specialist species and wormeries

Some earthworm species live in accumulations of organic matter, such as compost heaps. One such species is Eisenia fetida (brandling or tiger worm), recognisable by its stripy appearance, another is Dendrobaena veneta. These are the species most commonly used in wormeries, as their feeding activities speed up the composting process.

Problems

Worm casts consist of soil and waste excreted by the worms as they feed on organic matter. Worm casts can be a nuisance on lawns and gravel paths.