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Why Gardeners Should Love Earthworms!
Why Gardeners Should Love Earthworms!
Garden earthworms don’t receive much attention. Living underground or hidden in piles of leaves they are easily overlooked. But they deserve more attention from gardeners because they are vital to keeping soils healthy and fertile.
The Greek philosopher Aristotle (384 to 322 B.C), was an early advocate for earthworms, calling them the ‘intestines of the soil’.
However, it took a long time for others to catch up with his pioneering thinking.
Naturalist Charles Darwin (1809 to 1882) had a lifelong interest in earthworms. In 1837, he read a paper on the value of the earthworms as makers of soil to the Geological Society of London.
Although Darwin became much more famous for his works on Evolution – ‘On the Origin of Species’ (1859) and ‘The Descent of Man’ (1871) – he never lost his interest in earthworms.
Darwin studied the behaviour of earthworms in his garden at Down House in Kent. The results of spending 40 years observing their habits became the basis for his final book, ‘The formation of Vegetable Mould, Through the Action of Worms’ (1881). This, his last tome, became a best-seller largely due to its interest to gardeners.
To learn about Darwin’s experiments on worms, including his 29 year study with his famous ‘worm stone’ and why he played the bassoon and tin whistle to worms follow the link:
https://www.earthwormwatch.org/blogs/darwins-worms
To help your kids make their own wormery and begin to discover the hidden lives of earthworms:
https://www.woodlandtrust.org.uk/blog/2020/05/how-to-make-a-wormery
How Many Worm Species?
Here in Britain, we have nearly 30 species of earthworm. They vary in size and colour, but all contribute to creating fertile soils with good structure. About 16 of these species are likely to be found in our gardens.
The 3 Ecological Types:
1) Surface Dwellers. These earthworms don’t make burrows. They live on the surface of the soil, and you often find them in clumps of fallen leaves. The small, bright red, reddish brown and stripey worms in compost bins are members of this group.
2) Shallow Burrowing Earthworms. Pale coloured worms that make horizonal burrows as they move through the soil feeding.
3) Deep Burrowing Earthworms. Large earthworms that make deep, permanent vertical burrows in the soil. They feed by pulling fallen leaves and plant debris on the soil surface down into their burrows. This group includes those that produce the worm casts on lawns.
Worm casts on lawns are not a problem. Use a stiff broom to spread them when the lawn is dry. The worm casts will feed the lawn and keep it green and healthy.
How Do Earthworms Help The Gardener?
Earthworms improve garden soil in a number of important ways. These include:
Worm casts and burrow walls are enriched in soluble nitrogen, phosphorous, potassium and magnesium. In other words, earthworms enrich the soil for better plant growth.
Deep earthworm borrows help air and water penetrate the soil.
Earthworms are important recyclers of dead plant material. Their actions help promote soil microbial communities.
They help improve soil structure, mixing layers together, and cementing soil particles together.
A large population of earthworms in your garden is a good indicator of having healthy soil.
Earthworms are an important link in the wildlife food chain in your garden. Worms are a protein rich food for birds, frogs, and hedgehogs. As Franklin D. Roosevelt observed, ‘I think we consider too much the good luck of the early bird and not enough the bad luck of the early worm.’
How Do They Reproduce?
One longstanding myth about earthworms is that if you cut them in half, the two parts will regrow in to two new worms. This isn’t true.
The real story of earthworm reproduction is more interesting than the myth. Indeed, some species of worm can reproduce without a partner. This is type of reproduction is often used by the species than live near the surface or in the leaf litter where conditions can change very quickly.
The deeper burrowing earthworms live in a more stable environment and usually seek out a partner to reproduce. Earthworms are hermaphrodites, in other words each individual has both male and female reproductive organs, so both worms will produce a cocoon filled with eggs.
To learn more about earthworm reproduction:
https://sciencing.com/how-do-earthworms-reproduce-13406886.html
Why Do Earthworms Appear When It Rains?
This question still hasn’t been fully explained.
Charles Darwin demonstrated that worms were able to sense vibrations in the soil. It is suggested that when it rains the vibrations caused by raindrops hitting the soil brings the earthworms to the surface. The most likely explanation for this behaviour is that the earthworms can move freely over the damp soil surface and will seek out new food sources, search for a mate, or move to a new location.
Some birds exploit this usual behaviour by mimicking the rain vibrations by stamping on the ground with their feet, and then feasting on the unlucky worms!
https://www.youtube.com/watch?v=2QsqeHtRmHI
How To Attract Earthworms To Your Garden.
1) Don’t be too neat. Fallen and rotting leaves are food for worms. Sweep up fallen leaves and use them as a mulch on beds and borders.
2) Add extra rotting material like garden compost and rotted manure to your garden. It will feed your soil, increase its moisture holding, and attract worms.
3) Reduce the amount of deep digging. Earthworms are sensitive to soil disturbance.
4) Think very carefully before paving over your front garden or replacing your lawn with artificial grass. These surfaces are hostile for earthworms and other wildlife. Protecting the environment protects earthworms.
In Conclusion.
Earthworms are your friends in the garden. They remove and recycle decaying plant matter and improve the structure of soil.
They are the creators of soil in nature. A Charles Darwin concluded, ‘It may be doubted it there are any other animals which have played such an important part in the history of the world as these lowly organized creatures’.
If you are inspired learn more about earthworms and to get involved in their study:
