Garden worms help your garden grow

Learn how to encourage garden worms in your soil as worms help you to grow better plants.

Busy earthworms

Worms toil burrowing and bringing up nutrients and producing fine composted soil, whilst also incorporating leaves and other plant material into the soil creating soil humus. Worms improve drainage as well as water and nutrient availability for plants.

Garden worm populations can reach 250/ m2 soil, 2.5 million per hectare, in good soils. They eat their own weight in soil every day excreting it as fertile worm castings rich in micro-organisms and nitrogen as well as other nutrients now available for plant uptake.

Earthworms grow to 8 to 35cm in length in Europe and America, but some species native to Australia or South Africa manage 3m or even 6m in length respectively - thankfully they are just harmless soil/ plant eaters!

Worms come up to the soil surface at night, as they do on dull damp/ wet days, to forage for fallen leaf/ plant matter that they drag down into their burrow to feed on. It is common to find small stems and leaves dragged near/ around worm castings, evidence of recent worm foraging.

Lift up the cast and plant matter on the left and you'll find a worm hole right underneath!

Worms spend most of their time below ground burrowing in moist soil. Earthworms feed on decaying plant material and micro-organisms in the soil. They secrete a nitrogen rich slime which coats and stabilises their burrows. These burrows, although more frequent near the soil surface, can go down to some 2 metres, are commonly 2-5mm wide and help aerate and drain the soil, but also help the soil retain sufficient water to support plant growth.

Garden worms improve soil and help gardeners

• tilling the soil & helping soil preparation
• aerating the soil
• releasing soil nutrients like nitrogen and phosphorus
• incorporating organic matter
• building a fine crumbly aggregate soil structure
• encouraging soil living bacteria and fungi that work alongside worms to compost organic matter and release soil nutrients

How to help garden worms

• Don't be so tidy! - leave organic material on the soil (grass cuttings, dead annual weeds and leaves)
• add plenty of organic material (compost, leaf litter, farm yard manure) spread over the soil surface or mixed in to the top 10cm soil
• do not cultivate unless really necessary to break up compaction
• otherwise build a fertile soil with minimal disturbance and feed those worms
• ensure good drainage as they cannot survive in waterlogged soils as no oxygen means no life
• maintain soil moisture by mulching the soil surface - otherwise worms hibernate in dry soil

• on garden worms and soil


• on soil preparation


• on improving your garden soil


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