Earthworms are the digesters of the soil.
They can eat their way through large volumes of soil per year.
For gardeners, they are important in the soil, as they turn it over – taking good soil from the surface to lower parts, and bringing lower parts of the soil to the surface. They are the cultivators of earth.
Additionally, as they digest organic matter in the soil, they produce castings which are like concentrated small pellets of manure… ie fertiliser.
To encourage earthworms into the soil, you need to keep it well supplied with organic matter. Compost and mulch will ensure you have a good earthworm population.
Aim to replenish mulch at least every year to maintain high earthworm activity.
However, earthworms are not desirable in pot plants.
Their presence can assist in poor growth of pot plants, and can speed up the decomposition (collapse) of the potting mixture.
To remove earthworms from pots, use 1 teaspoon of Condy’s Crystals in 5 Litres of water. Depending on the size of the pot, 5 litres of this mixture will generally be sufficient to bring the worms to the surface of the potting mix from which they can be removed. Unfortunately they may die at about the same time during this process of treatment or transferral to a new location.
For more information on Earthworms check out books at your local bookstore.