“It may be doubted whether there are many other animals which have played so important a part in the history of the world…”
Charles Darwin, The Formation of Vegetable Mould through the Action of Worms, 1881
Earthworms aren’t glamorous. You won’t see them gracing the front of a conservation campaign, and you’re unlikely to spot a “Save the Worm” tote bag. But if you care about healthy soil, thriving gardens and food security, then you should care—deeply—about worms.
Because while pandas and polar bears tug at the heartstrings, it’s earthworms that quietly keep our planet ticking over.
What Do Earthworms Actually Do?
Earthworms are often called “ecosystem engineers”, and it’s not just a flattering nickname. These little creatures perform a whole host of essential jobs that help keep our gardens – and the wider environment – alive and kicking.
1. They Recycle Nutrients
As earthworms wriggle through the soil, they munch on dead leaves, organic matter, and tiny microbes. What comes out the other end is called a worm cast—and it’s gold for gardeners.
Worm casts are packed with nutrients, often containing up to five times more nitrogen, phosphorus and potassium than the surrounding soil. It’s no wonder plants love them.
2. They Aerate and Drain the Soil
Worms tunnel as they move, naturally aerating the soil and improving its structure. These little channels help water drain more effectively, reduce compaction, and bring oxygen down to the roots—exactly what plants need to thrive.
3. They Help Prevent Flooding and Erosion
Because their tunnels allow water to flow through the soil more efficiently, earthworms can help prevent surface water from pooling—meaning they may play a role in reducing localised flooding and slowing erosion in heavy rain.
4. They’re Indicators of Soil Health
Earthworms are very sensitive to chemicals and pollutants. If your soil is contaminated with pesticide residues or heavy metals, earthworm populations will start to decline. In this way, worms act as a natural barometer of soil quality—if your worms are happy, chances are your soil is too.
5. They Support the Entire Food Chain
Worms are a key food source for many wild animals—hedgehogs, badgers, robins, and more. If earthworm numbers dwindle, it can have a knock-on effect right up the food chain.
Earthworms vs. Pandas (Yes, Really)
Pandas are cute, but earthworms? Earthworms are essential.
Without them, we’d have poorer soils, less food, more pollution, and worse flooding. They support biodiversity, improve growing conditions, and even help clean up contaminated land.
In fact, scientists have ranked earthworms as one of the most influential species in Earth’s history—right up there with us humans. Darwin himself devoted 39 years of study to them for good reason.
How Can Gardeners Help Earthworms?
Want to look after your garden’s worm population? Here’s what you can do:
- Avoid overusing fertilisers or pesticides – these can harm worm communities
- Add compost and organic matter – earthworms love a rich, crumbly soil
- Don’t dig too much – excessive tilling disrupts worm tunnels and can hurt them
- Leave leaf litter in parts of the garden over winter – worms will break it down for you
- Keep your soil moist but well-drained – worms need damp conditions to thrive
The more worm-friendly your garden becomes, the more your plants (and the planet) will benefit.
A Final Word for the Worms
They might not win any beauty contests, but earthworms are the life of your soil. They fertilise, ventilate, and stabilise the ground beneath your feet, often working harder than any spade or fork ever could.
So next time you spot a worm wriggling in the flowerbed, give it a silent thank you—and do what you can to keep its underground world healthy.
Because if we look after the worms, they’ll keep looking after us.
This article is based on a 2017 piece in The Conversation by Sarah Johnson,PhD Researcher in Environmental Science, King’s College London.
