Britain has about 16 species of earthworm that are likely to be found in gardens and in total nearly 30 species can be found in the UK. They vary in size and colour, but all help create good soil structure and fertility.
Britain has about 16 species of earthworms likely to be found in gardens
Earthworms occur in most soils
Some earthworms can be used in wormeries to make compost
Worm casts can occur on lawns
What do earthworms do?
Earthworms are a familiar sight to gardeners and help create and maintain 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 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
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.
Pot worms (Enchytraeidae)
They are often abundant in decaying organic matter, especially if it is damp. Like the larger earthworms, they feed on and help break down decaying organic matter and will not cause any damage to living plants. Some further information on these worms can be found at iNaturalistUK .
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