Members' experiments

Winter green manures for gardeners

Each year we organise several citizen science experiments that our members can participate in to help inform the way we grow organically today. This experiment is 2022 - Winter green manures for gardeners.


Winter green manures are sown in the autumn to protect the soil over the winter. They help to protect the soil surface from heavy rainfall which can damage the soil structure, causing it to set like concrete in drier weather. They also prevent nutrients from being washed out of the soil.

However, many winter green manures sold in gardening catalogues were originally designed for agricultural situations, often containing plants that become tough and difficult to chop down and incorporate into the soil.

We would like to test a diverse mix that is suited for a range of garden situations.


To test a diverse green manure mix that is suitable for over winter use in a garden setting.

You will need:

  • Two 1 x 1 m plots next to each other

We will provide:

  • Seed, protocols and recording forms


  • September 2022 to April 2023

Time required:

Around 1 hour to sow the trial, then 15 minutes every month to monitor the plants.

Deadline for sign up:

22nd August

Maximum number of participants:


This experiment is now fully subscribed.

Please submit your results online here.