There are two main varieties: bush beans and vine (pole) beans.
Bush beans tend to mature more quickly. They are called "determinate" plants because they yield all of their beans at one time.
"Indeterminate" vine varieties mature more slowly, but they yield a better harvest per square foot, and they tend to have fewer problems with disease. On a trellis, the plants can grow 6-8 feet high.
Lima beans are native to Peru, and they grow best in warm climes where the temperature stays about 60-70° Fahrenheit throughout the growing season. Plant the seeds 2-4 weeks after the final spring frost, once the weather begins to warm. The temperature should not dip below 60° Fahrenheit in the evenings.
Make sure not to plant the seeds too early! They will rot in cool, moist earth. If you plant them too late, however, the high temperatures may interfere with pod growth.
Plant the beans 1-2 inches deep in soft soil. Set bush beans 4-6 inches apart, and pole beans 8-10 inches apart. Sow them with the eye of the bean facing downward into the soil. If you are planting multiple rows of lima beans, make sure to leave 24-36 inches between the rows for easy access and unrestricted growth. The perfect planting site is sunny, well-drained, and moderately fertile. Aim for soil that is slightly acidic, with a pH of 6.0-6.8.
Avoid high-nitrogen soil, and do not use a fertilizer that's been infused with extra nitrogen. Nitrogen fertilization will make the plant grow lush leaves, but it may limit bean pod growth.
Pole Lima beans need a pole or trellis to reach their full growing potential. Set this up as soon as you plant the seeds (or even earlier) so that you do not risk damaging the delicate roots.
Keep the earth damp, but not soggy. Be careful not to water too heavily or too frequently, lest you drown the delicate lima bean seedlings. Be aware, however, that they require about one inch of water each week (from rain or irrigation) during the blossoming and pod development stages.
Pour the water at the base of the plants, not over the top: disease and mildew can develop in consistently-wet foliage.
Spread mulch around the base of the plant to conserve moisture. This will keep you from having to water every day, as the hot season develops, and it should keep the weeds down.
Try to pick pods as soon as they're ready. This will coax the plant to create new pods. Once you allow a couple of bean pods to over-mature, this usually triggers the entire plant to stop blooming and producing pods.
Bean-Lima, Phaseolus lunatus
Pollination, self; Life Cycle, annual; Isolation Distance, 50 feet
Lima beans are inbreeding plants. All varieties will cross with each other but not with common garden beans (Phaseolus vulgaris). It is always best to save seed from plants that ripen first and are free from disease. Leave pods to dry on the vine. When you can hear the seeds rattle in the pods, they are ready to be picked. They shatter easily and must be picked gently. If weevils are present, pick the pods earlier, spread them to dry, and then shell. Freeze seed to eliminate weevil eggs. Crush the pods in a cloth or burlap sack and winnow off the chaff. For next year's planting select the best looking beans.