Seven-year lima (Phaseolus lunatus) is now available from ECHO. The seven-year lima is also called Madagascar Bean, Painted Lady or Tropical Lima. Our seeds originally came from the Asveldt Ranch in Mwenezi, Zimbabwe, where the seven-year lima is planted around houses and grows on top of roofs, away from foraging goats. The common name refers to its ability to remain productive for several years. A unique quality of this 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. The seven-year lima bean is characterized by vigorous vining growth that quickly develops into a thick mat about 2’ high. The beans are white with a mix of deep burgundy.
The plant does best in a dry, frost-free growing season but if frosted, will die back and then regrow. Its growth is slowed down by cool weather. It is fairly drought-resistant and requires light, well-drained soil with a pH of 6 to 7. It is tolerant of a wide variety of soil types. The beans can be planted in mounds and trellised, or can be broadcast to produce a thick ground cover. Before the wet season, the vine should be pruned back to get a healthy flush of new growth to withstand the intense rains. The cuttings can be fed to animals as a mix with other forages.
Pods are produced continually throughout the life of the plant, providing multiple harvests. Dry beans are ready for picking after 3-5 months. The seeds are easy to collect and can be kept in cool, dry storage for many years. Seven-year lima bean is extremely hardy and vigorous. It is susceptible to root-knot nematodes, though it does continue to persist even with infected roots. When some other legumes on ECHO’s farm were infested with leafhopper two summers ago, seven-year lima suffered the least damage and continued to produce, showing good vigor.
The beans can be eaten as a pulse. Beans should be soaked 4-6 hours before cooking, then boiled for 1 ½ hours. The water should be discarded before eating the beans. The beans and leaves should never be eaten raw because they contain a toxin, hydrocyanic acid, which is removed with soaking and cooking. The lima beans are a nice protein addition to soups, stews and casseroles. Cooked beans can be refrigerated and eaten cold.
Ju, G. 2003. Seven-Year Lima Bean. ECHO Development Notes no. 81