The
Three Sisters are the three main agricultural crops of some
Native American groups in
North America squash,
maize, and climbing
beans (typically
tepary beans or
common beans).
In one technique known as companion planting, the three crops are planted close together. Flat-topped mounds of soil are built for each cluster of crops. Each mound is about 30 cm (1 ft) high and 50 cm (20 in) wide, and several maize seeds are planted close together in the center of each mound. In parts of the Atlantic Northeast, rotten fish or eel are buried in the mound with the maize seeds, to act as additional fertilizer where the soil is poor.[1][2] When the maize is 15 cm (6 inches) tall, beans and squash are planted around the maize, alternating between beans and squash. Milpas are farms or gardens that employ companion planting on a larger scale.[3]
The three crops benefit from each other. The maize provides a structure for the beans to climb, eliminating the need for poles. The beans provide the nitrogen to the soil that the other plants utilize and the squash spreads along the ground, monopolizing the sunlight to prevent weeds. The squash leaves act as a "living mulch," creating a microclimate to retain moisture in the soil, and the prickly hairs of the vine deter pests.
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