Lima Bean: 7-Year Lima
(Phaseolus lunatus)

Phaseolus lunatus is a vining (indeterminate) or bush-type (pseudo-determinate) legume from Central and South America. Vining types are vigorous, perennial, and reach 2-6 m in length. Bush-type cultivars are annuals and reach heights of 0.25-1 m. Leaves are trifoliate, present alternately on the stem, and range from pubescent to glabrous. Inflorescence can reach 15 cm in length and bear up to 25 white-to-violet flowers. Pod lengths are 5-12 cm and contain 2-4 seeds each. Pod and seed shape, size, and color are highly variable and dependent upon cultivar.

Half white and pink beans.

This semi-perennial lima bean variety originated in Central America but has been bred in parts of East Africa and South Africa and is commonly used as a cover crop. The name comes from its ability to remain productive for several years. If grown along the ground, it can produce a 60 cm high mat of foliage that smothers weeds. It can also be trellised for easier seed harvest. The seeds are large, with distinctive red caps atop the seeds. In Mwenezi, Zimababwe, the Seven-Year Lima is planted around houses and grows atop roofs of homes away from foraging goats.

The unique quality of this lima bean is its ability to smother and suppress weeds while providing continual forage for animals, beans for human consumption, a perennial dense cover crop for tropical dry regions, and a green manure that adds nitrogen to the soil. Flowering begins 60-90 days after sowing. Occasional pruning is recommend to stimulate new vigorous growth and rejuvenate the mat. The ground can be completely covered in 60-75 days when sown every square-foot and temperatures are warm. Dry beans are ready for picking after 7-9 months. Susceptible to root-knot nematodes though it does continue to persist with infected roots.