The Lima bean (Phaseolus lunatus) is native to Central America and is often referred to as the "butter bean." It was in cultivation 7,000 years ago in Peru. The beans are white and often are available in two sizes. The plant is considered a warm-season vegetable. The Lima bean is excellent as a dried bean or fresh, offering a high protein content of 18 percent in dry beans.
The Lima bean is considered a tender annual, so it is imperative that they be planted three to four weeks after the last frost occurs. Ideally, the soil temperature should hover at around 65 degrees Fahrenheit for the best germination results. Lima beans can be successfully started indoors and then transplanted into the garden to give them a head start and have an earlier harvest date.
Sunlight and Soil
Lima beans prefer full sun. They will grow in partial shade, but the harvest yield will be considerably less. Soil should have a pH balance of 6.0 to 6.8. Lima bean plants require a great deal of organic material in the soil and thrive on peat moss, leaf mulch or sawdust at the time of planting. The soil should be well-drained with no standing water. Lima beans will benefit from having a 2- to 3-inch layer of mulch across the soil to help water retention and keep weeds at bay.
Lima beans should be placed 2 inches beneath the soil surface and a minimum of 3 inches apart for best planting results. The plants will benefit from having stakes placed in the rows so the beans can easily climb up on. The ideal row spacing is 24 inches so the plants have ample room to spread. Beans that are crowded will utilize each other for climbing up the stakes.
Lima beans like moist conditions but don't do well if they're waterlogged. Waterlogging can cause the bean's outer skin to crack. It is best to water, using a soaking hose or drip irrigation system instead of an overhead watering system because heavy water on Lima bean flowers can reduce bean production.
Cultivation and Harvest
The root system of the Lima bean plant is very delicate, so cultivation should be gentle so the shallow root system is not disturbed. Nitrogen fertilizers should be avoided with Lima beans because nitrogen encourages foliage growth instead of bean production. Lima beans can be harvested 60 to 80 days after sowing. Pole varieties of Lima beans can be harvested 90 days after sowing. The harvest can begin when the seed pods are plump. Seed pods left for an extended period on the vine will result in tough and hard beans.