Building a Garden Planner for Our Allotment
Our allotment garden has 24 plots across 12 families. Before GreenPlot, coordination was a WhatsApp group and a paper sign-up sheet for the rototiller. Neither worked well — the sheet was outdated, nobody photographed it, and the group chat was 80% irrelevant notifications.
GreenPlot started as a spreadsheet that I maintained, then became a shared Google Sheet, then a Git-tracked JSON file when I realised the spreadsheet was getting too complex and we kept overwriting each other. The current version is a static web app that reads and writes local JSON files through the File System Access API — no server, no account, works offline.
Each plot is a 4×8 metre grid of 32 cells. Each cell holds one crop entry: species, variety, planting date, expected harvest window. The planner overlays a rotation recommendation: if cell (2,3) had tomatoes last year, it suggests brassicas or legumes this year and flags if someone plants tomatoes again.
The companion planting chart is the feature people use most. Hover over a cell and it highlights compatible neighbours in green and incompatible neighbours in red. Fennel has the most red cells — it's allelopathic to almost everything except dill.