Look up companion planting compatibility for common vegetables and herbs. Find compatible and incompatible crop pairs with recommended spacing.
Companion planting is the practice of placing specific crops near each other to take advantage of beneficial interactions — pest deterrence, pollination support, nutrient sharing, or physical support. The classic example is the Three Sisters: corn provides a trellis for beans, beans fix nitrogen for corn, and squash shades the soil to retain moisture.
This guide lets you select a crop and instantly see which species are compatible companions and which should be kept apart. Compatible plants may repel each other's pests, attract beneficial insects, improve flavor, or simply coexist without competition. Incompatible plants compete aggressively, attract shared pests, or release allelopathic chemicals that inhibit neighbors.
Use this lookup alongside your garden layout or field planting plan to maximize symbiotic relationships. Whether you are a beginner or experienced professional, this free online tool provides instant, reliable results without manual computation. By automating the calculation, you save time and reduce the risk of costly errors in your planning and decision-making process.
Strategic companion planting can reduce pest pressure, improve pollination, and increase overall garden productivity without additional chemical inputs. It's especially valuable in small-scale and organic production systems where every square foot counts. Having a precise figure at your fingertips empowers better planning and more confident decisions. Manual calculations are error-prone and time-consuming; this tool delivers verified results in seconds so you can focus on strategy.
Companion planting is based on empirical observation and horticultural research rather than a single formula. Compatibility matrices are compiled from decades of garden trials and traditional knowledge.
Result: Good: Basil, Carrots, Marigolds · Bad: Fennel, Cabbage
Basil repels aphids and whiteflies that attack tomatoes. Marigolds deter nematodes. Carrots loosen soil around tomato roots. Fennel inhibits most plants allelopathically, and brassicas compete for similar nutrients.
Allelopathy, trap cropping, habitat for beneficial insects, and physical facilitation are the main mechanisms. Research from universities and organic farming institutes has validated many traditional pairings while debunking others. Always look for locally relevant trial data.
Alliums (onions, garlic, chives) repel many insect pests. Umbellifers (dill, cilantro, parsley) attract predatory wasps and hoverflies. Legumes fix nitrogen for neighboring heavy feeders. Asteraceae (marigolds, sunflowers) provide habitat for beneficial insects.
Small-scale market gardeners use companion planting intensively to maximize per-bed revenue. Interplanting fast-maturing crops (lettuce, radishes) between slow-maturing ones (tomatoes, peppers) makes efficient use of space and time.
Many companion planting relationships are supported by research — for example, marigolds suppressing nematodes and basil repelling certain insects. Others are based on traditional observation with less scientific backing. Results vary by region and conditions.
Companions should be within 2-4 feet of each other for pest-deterrent effects. Interplanting within the same bed is ideal for small gardens. In larger gardens or farms, adjacent rows or beds provide benefits as well.
Corn, beans, and squash — a traditional Native American polyculture. Corn stalks support climbing beans, beans fix nitrogen, and squash leaves shade the soil to suppress weeds and retain moisture. It's a classic companion planting system.
It can reduce pest pressure but rarely eliminates the need for all pest management. Think of companion planting as one tool in an integrated pest management (IPM) strategy, not a standalone solution.
Incompatibility stems from allelopathy (chemical growth inhibition), competition for the same nutrients or rooting zone, attraction of shared pests, or physical interference. Black walnut, for example, releases juglone that inhibits many species.
Yes. Pairing herbs with vegetables in the same large container or grouping containers together can provide companion benefits. Choose dwarf or compact varieties to avoid overcrowding in limited space.