The Great GROW Experiment - challenges and opportunities for hypothesis and place-based citizen research in food growing

Despite the exponential increase in citizen science projects in the last twenty years, most garden-focused projects have involved measuring taxon biodiversity. There are relatively few hypothesis-led citizen science projects, despite household and community growers having a role in meeting rising food needs and helping reduce soil and ecosystem degradation. Regenerative growing practices, e.g. polycultures, mulching and cover crops, are widely practised on a small-scale but there is a lack of robust supporting scientific data. Citizen science offers a mechanism for small-scale growers to contribute data and provide scientists with both quantitative and qualitative data on food growing from domestic growing spaces. Hypothesis-based citizen science also has potential to improve scientific literacy and communicate the scientific method with participants, helping growers understand their growing place and make informed decisions on the techniques they use.The GROW Observatory is a EU Horizon 2020 funded research and innovation programme. Its aim is to establish a large-scale Citizen Observatory for environmental monitoring through citizen science. The Great GROW Experiment was one of the activities run by the Observatory. It was an innovative, hypothesis-driven experimental, rather than observational study, with a focus on training participants to be ‘citizen researchers’. Through a free massive open online course (MOOC), participants were taught how to design research experiments in their growing space, implement and participate in a collective experiment comparing monoculture and polyculture growing, and interpret their own results. The Experiment ran from May 2018 until October 2018 with experimenters supported by regular online contact and monthly online meetings with the GROW team.The Experiment supported a local and global understanding of place, training participants to understand their own growing space and its environmental conditions i.e. collecting different landscape and soil observations in addition to yield data. Furthermore, embedding the Experiment within a MOOC allowed people from many locations to exchange knowledge and discuss their participation, giving a broader view and understanding of one's place in a European context e.g. the experiment highlighted the different harvesting times across Europe, beginning earlier in the south.The training and support offered encouraged a reflective approach to citizen science, place and participation through a) observation; b) considering data quality; and c) survey questions that evaluated present and future participation. Several participants are continuing with experiments on their site, including experiments they developed themselves. Here we present and discuss some of the challenges and opportunities for hypothesis and place-based citizen research in food growing, including how future experiments could be more place-based and shaped by using locally adapted crop varieties, local planting and harvesting calendars, and local knowledge of citizen researchers in the design while still creating comparable and scientifically robust results.