Members' experiments

Does comfrey liquid feed live up to its claims?

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 - Does comfrey liquid feed live up to its claims?

What we want to find out

The classic claim in gardening journals is that comfrey liquid feed is high in potash, so is good for tomatoes; whilst nettle liquid is high in nitrogen so good for leafy crops. This claim is actually based on the early work of our founder Lawrence Hills. In those times, testing was expensive which restricted the number of samples that could be taken, but now that testing is easier to do, we thought that it was time to revisit these claims and test liquid feeds made from a wider range of sites.

You will get the chance to get your own home-brewed liquid, tested by Coventry University, and contribute to the first nationwide dataset of homemade organic liquid feeds.

The sign up for this experiment has now closed.

The experiment - what's involved

We would like participants to take samples from their own homemade comfrey and nettle liquid feeds. You will take a cut from your comfrey and nettles in May, let it brew until the end of July, then send the samples back to us where they will be tested at the Centre for Agroecology, Water, and Resilience at Coventry University. As we only have limited resources for testing, please only sign up to do this experiment if you know that you will be able to send samples back to us.

What we'll provide

Closer to the start time of the experiment you'll receive an information pack that will include the following:

  • Instruction pack
  • Sample tubes
  • What you'll need
  • Two large buckets with lids
  • Supply of comfrey and nettles

Our Knowledge Transfer team will send out experiments and information packs in the post to all participants during the first week of May, so please keep an eye on the post. We'll post updates about our experiments on social media and in our Organic Matters newsletter.

Dates for your diary...

  • Experiment start date: Mid-May.
  • Experiment end date: End of July.
  • All results are to be submitted to us by the end of September.

How much time will I need to set aside to take part?

Not much at all. We're asking for participants to set aside around an hour to cut comfrey and nettles and set up making liquid feeds. A further 15 minutes to take samples once the liquid feed has been created. This is the perfect experiment, for members passionate about our research and who want to contribute to the first nationwide dataset of homemade organic liquid feeds.