Green bean and pole bean companion plants
Green beans and pole beans (*Phaseolus vulgaris*) are among the most companion-planted vegetables in American gardens, partly because they are central to the Three Sisters polyculture system and partly because the Mexican bean beetle (*Epilachna varivestis*) is a persistent problem that companion.
Green beans and pole beans (Phaseolus vulgaris) are among the most companion-planted vegetables in American gardens, partly because they are central to the Three Sisters polyculture system and partly because the Mexican bean beetle (Epilachna varivestis) is a persistent problem that companion planting can partially address.
Beans also fix atmospheric nitrogen through Rhizobium bacteria in root nodules — a well-documented benefit that is often misrepresented in companion planting guides. The nitrogen benefit is indirect and timing-dependent.
The companion planting table
| Plant | Role | Friend / Foe / Neutral | Notes |
|---|---|---|---|
| Corn | Structural support for pole beans; Three Sisters system | Friend | Must be planted 2–3 weeks before beans |
| Summer savory (Satureja hortensis) | Mexican bean beetle deterrence | Friend | Most experimentally supported aromatic companion |
| Squash (Three Sisters) | Living mulch; weed suppression; moisture retention | Friend | Three Sisters system |
| Carrot | Compatible root depths; efficient space use | Neutral | No documented pest benefit |
| Cucumber | Compatible; different pest species | Neutral | No interaction documented |
| Marigold, French (Tagetes patula) | Beneficial insect habitat; nematode management | Friend | Bed edges; useful for following-year nematode management |
| Nasturtium | Aphid trap crop; some bean aphid benefit | Friend | Monitor for infestations |
| Dill (in flower) | Attracts parasitic wasps; beneficial for Mexican bean beetle | Friend | Allow to flower at bed edges |
| Sweet alyssum | Syrphid fly support | Friend | Bed edges |
| Rosemary | Aromatic; may deter bean beetles | Friend (tentative) | Traditional use; weak evidence |
| Potatoes | Mexican bean beetle/Colorado potato beetle crossover | Foe | Separate in rotation; do not plant adjacent |
| Onions / garlic | Inhibit bean root nodule formation in some studies | Foe | Some evidence of allium sulfur suppressing Rhizobium |
| Fennel | Strongly allelopathic to beans | Foe | Separate beds entirely |
| Beets | Competition in heavy soils; some sources cite inhibition | Foe (contested) | Keep separate if soil is heavy clay |