Companion Planting Calculator

Companion planting pairs crops that benefit each other — through nitrogen fixation, pest confusion, shade sharing, or physical support — and this calculator scores how favorable your growing conditions are for getting those benefits from your chosen primary crop. It starts from a base compatibility score reflecting how many well-documented companion pairings that crop has (beans and corn, for instance, score high because beans fix nitrogen the corn can use and corn provides a natural trellis, the classic Three Sisters pattern), then adjusts up or down for sunlight and soil pH, since a companion planting scheme only pays off if the growing conditions themselves support healthy plants in the first place. Sunlight below 6 hours a day drags the score down because most companion vegetables need substantial direct light regardless of what's planted next to them, and soil pH outside the roughly 6.0–7.0 sweet spot most vegetables prefer does the same.

The resulting score drives estimated yield boost and pest reduction percentages, both proxies for the documented but highly variable real-world benefits of companion planting — actual outcomes depend heavily on the specific pairing, planting density, and local pest pressure, so treat these percentages as directional rather than a guaranteed figure. What this tool does not account for: your bed's specific companion crop selections (it evaluates your primary crop's general potential, not an actual planned pairing), regional pest pressure, bed size or plant count, or the incompatibilities some crops have with specific companions even when the primary crop's overall score is favorable.