An online database and cross-platform, game-like client where gardeners/farmers (small or large scale) can log their actions and measurements (such as weather, yield, current plant size).
Any user can then play it back visually, or play with the data and see a simulation inferred from the knowledge database, or calculate an optimal design within given constraints, inferred from the knowledge available at that time.
This is both a tool for playing, in order to entertain and inspire people, as well as a serious feedback and design tool. There will be a user feedback system to value the accuracy of the data. It is allowed to enter and share mock farming data, as long as it's tagged as being fantasy, to exclude it from the analyses.
Things like dietary information, tiredness and bio-constructions will be included as well, to improve optimizations of a garden design with (partial) self-sufficiency in mind.
The UI will resemble a garden, and can switch to simplified views.