The kidney bean (Phaseolus vulgaris), domesticated in Central and South America 7,000 years ago, sports a burnt red outer shell with a cream-colored flesh. A popular addition to chili, the kidney bean can also be dried or canned. The kidney bean must be boiled for at least 10 minutes prior to consuming to degrade the toxin within the bean known as lectin phytohaemagglutinin. If boiling does not occur, the bean can cause severe stomach upset, vomiting and diarrhea, according to the New Zealand Food and Safety Authority.
A temperate to sub-tropical plant, the kidney bean requires planting after all danger of frost has passed. The seeds germinate best when the soil temperature is above 64 degrees F. The kidney bean plants require a minimum space between plants of 11 inches. Plant kidney beans 1 inch below the soil's surface for the best germination results. They prefer a soil pH of between 6 to 7.
Kidney bean plants are a legumes. Legumes have the unique ability of fixing nitrogen into the soil. The plant has a symbiotic relationship with a bacteria known as "rhizobia." The kidney bean plant provides all the nutrients that the rhizobia bacteria require to live and in exchange the bacteria produces nitrogen into the surrounding soil which can be utilized by the kidney bean plant for growth. Kidney beans can be purchased inoculated with the rhizobia bacteria prior to planting. Inoculation gives the beans a better chance to germinate and grow successfully.
Apply at least 2 inches of mulch around the base of the kidney bean plant. The kidney bean plant produces a shallow root system when growing, which can be easily damaged during cultivation and weed removal. Adding mulch helps protect the plant's roots. Mulch also helps prevent bean pods that droop to the ground from rotting.
Fertilizer During Growth
The kidney bean plant does not require fertilizing for adequate growth because the surrounding soil contains abundant nitrogen from the rhizobia bactera in the plant's root system. Kidney bean plants are often planted to add nutrients to the soil.
Watering and Harvest
Keep the soil moist around the kidney bean plant for adequate growth. Once the plant sets bean pods, refrain from watering the plant so the pods dry out prior to harvest. The kidney bean plant is ready for harvest 4 to 6 weeks after planting. Harvest the pods when they dry out and change to a dull tan color, according to Purdue University. Kidney beans are considered a "dry bean," due to their need to be harvested when the pods have thoroughly dried on the vine.