Bush beans are compact, self-supporting plants that typically grow to one to two feet and produce a concentrated harvest over a shorter period. Companion planting leverages natural plant interactions to enhance the garden ecosystem. By strategically placing certain crops near bush beans, gardeners can improve overall yield, naturally deter common pests, and optimize the use of garden space. This method focuses on creating mutually beneficial relationships between different plant species.
Protective Companions for Bush Beans
Planting specific herbs and flowers near bush beans offers a natural defense against common garden pests. Summer savory is a particularly effective companion, known to repel bean beetles and enhance the flavor and growth of the beans themselves. The strong, aromatic oils released by this herb confuse the insects that rely on scent to locate their host plants.
Other aromatic herbs, such as dill and rosemary, also deter insects like the Mexican bean beetle. Dill attracts beneficial insects, such as hoverflies and parasitic wasps, which prey on aphids. Catnip is an effective repellant for flea beetles, which can damage young bean plants.
Certain flowers and vegetables can also be used as trap crops or insect attractants to protect the beans. Nasturtiums are often used as a trap crop, drawing aphids away from the beans, while their presence also helps deter bean beetles. Planting potatoes in alternating rows with bush beans creates a reciprocal protective relationship: the potatoes help repel the Mexican bean beetle, and the beans help deter the Colorado potato beetle, which feeds on the potato foliage.
Soil and Nutrient Enhancers
Bush beans, as legumes, have a symbiotic relationship with Rhizobium bacteria that allows them to fix atmospheric nitrogen. The bacteria form nodules on the bean roots, converting nitrogen gas into usable forms like ammonia. These nitrogen compounds are released into the soil as the root nodules decompose, effectively enriching the soil for nearby plants.
Plants that require large amounts of nitrogen benefit greatly when planted near bush beans. Examples include cucumbers, tomatoes, and various members of the cabbage family, such as broccoli and cauliflower. These companions utilize the residual nitrogen provided by the beans, which can reduce the need for synthetic nitrogen fertilizers.
Beyond nitrogen, some companions improve the physical soil environment around the bean roots. Radishes, with their quick growth and taproots, help to loosen and aerate compacted soil, benefiting the bean’s root system. Beets are beneficial because their different root depths allow them to coexist without significant resource competition. Sweet corn can also act as a microclimate enhancer, providing light shade that bush beans tolerate well.
Incompatible Neighbors
Some common garden plants should be kept separate from bush beans because they actively hinder the bean’s growth or invite shared problems. The Allium family, which includes garlic, leeks, and onions, is widely considered incompatible with beans. These plants can inhibit the growth of beans, possibly by releasing sulfur compounds that interfere with the beneficial nitrogen-fixing bacteria on the bean roots.
Fennel is another plant that should not be placed near bush beans because it is known to exude allelopathic chemicals. These biochemicals influence the growth and development of neighboring plants, and the compounds released by fennel can stunt the growth of the beans.
Finally, while some Brassica family members like cabbage are listed as compatible, other brassicas or heavy feeders should be chosen carefully due to potential competition. Planting beans near other legumes, like peas, can also be problematic since they share a susceptibility to similar pests and diseases, which can lead to a more severe infestation for both crops.