The National Allotment Society - National Society of Allotment and Leisure Gardeners Ltd

Survey Results from Earthworm Watch

Autumn survey of Earthworm Watch launches soon after wriggling into Wales

The warm wet summer has led to a surge in records for the people-powered research project Earthworm Watch. Earthworm Watch is a national citizen science project that asks public audiences to count earthworms and categorise soils to map earthworm abundance, soil type and soil carbon content in different habitats in urban green spaces. The project is a partnership between Earthwatch Institute the Natural History Museum in association with the Earthworm Society of Britain with the aim to better understand the human impact on earthworms and their habitat preferences.

This year the team established new data from Wales in June after an earthworm event at Amgueddfa Genedlaethol Caerdydd - National Museum Cardiff with scientists and OPAL celebrating their Wriggle: the wonderful world of worms exhibition. Their latest results revealed that areas with organic fertilisers contained 50% more earthworms, regardless of habitat type and that the highest densities of earthworms are found in vegetable beds.


Dr Alan Jones doing the Earthworm Watch survey at the National Museum Cardiff’ Wriggle event in June

The team are wriggling their way towards their target of 500 unique data points with UK wide coverage, but are asking the green-fingered this autumn to grab a trowel, visit a garden, allotment or community space for an hour and help scientists fill in the data gaps. To sign up and take part this autumn visit

What do you need to do?

  1. Request a survey pack or download and print your own copy of the instructions booklet at:
  2. Follow the instructions booklet and dig two 20cm by 20cm by 10cm pits in two different habitats (a lawn and a flowerbed for example), measuring soil properties such as moisture and categorising the earthworms you find in your pits.
  3. Submit your results online at 

What do the results mean and how can you attract earthworms to your garden?

Victoria Burton, PhD researcher on the project who has been analyzing the results reported that:
Last year we found that earthworms prefer vegetable and flower beds but collecting additional data  has revealed that whether gardeners fertilise their plot is more important than habitat type. Areas with added organic fertilisers such as compost and farmyard manure had 50% more earthworms regardless of habitat, but this effect was not seen with artificial fertilisers. If you want to encourage more earthworms in your garden it seems that adding organic fertiliser really does help.’ 

With the highest density of earthworms still occurring in vegetable beds it seems that earthworms prefer areas where manure, compost, leaf-mould, or compost bark are used. Results also suggest that well-kept lawns aren’t the best habitat for earthworms, despite less disturbance from digging.

Visit to look at some ways that could help encourage more earthworms to your garden.