The lima bean plant moves through visible stages as it grows, making it a good learning tool for classrooms and gardeners alike. Certain lima bean varieties have even undergone adaptations over time. These Guatemalan natives were nutritionally relied upon by prehistoric tribes that harvested and dried them for easier transportation. Lima beans eventually migrated to continents to the north and south. Their name comes from European explorers, who noticed them on their first visit to Lima, Peru. Most lima beans cultivated today are harvested to eat fresh during the growing season, but their growth habit remains similar.
Lima beans come in many shapes, sizes and colors, such as red and purple, although most grown in the United States are pale green or creamy white. The bean seeds are flat, kidney-shaped, creamy in texture and high in dietary fiber and iron.
Lima bean seeds don't start to grow until they are exposed to water and a temperature that is at least 60 degrees Fahrenheit. When water enters a small hole, called a micropyle, where the seed curves inward, it stimulates growth. Each seed is comprised of two halves, called cotyledons, which contain an embryonic plant between them. The halves feed the plant as it develops.
A radicle, or root, develops and begins to grow downward as a stem pushes up. The root system continues to expand and draw nutrients from the soil as the rest of the plant, now a seedling, sprouts leaves. Photosynthesis continues the feeding process, with the leaves converting light to nutrients needed to grow.
Soil and Location
Original lima bean plants grew as vines, but many varieties have since been hybridized for easier care and harvesting. Optimal lima bean plant growth requires an area that includes well-drained soil and that is located in full sun. The plants are more sensitive to cold than other bean types. Frost can stunt their growth or kill them.
Maturing lima bean plants sprout small, white flowers, which are necessary for fruit production. Bees and other insects pollinate the flowers, which then grow curved pods, approximately 3 inches long, that contain more bean seeds. Standard varieties are ready to be harvested in three to four months, while small and bush-type varieties take longer. Harvest the beans when the pods are plump, firm and still green.