Lima beans are a popular garden legume. Whether these plants require a trellis depends entirely on the specific cultivar chosen for planting. Lima beans are categorized by their growth habit, which determines if the plant will remain compact or produce long, vining stems that need vertical support. Understanding this difference is key to a successful planting and harvest.
Distinguishing Bush and Pole Lima Beans
Bush and Pole are the two main growth types, differing significantly in stature and production cycle. Bush lima beans have a determinate growth habit, growing to a compact, self-supporting height of 18 to 24 inches. They stop growing once they begin flowering and setting pods, maturing quickly in 65 to 75 days. Because of their short, sturdy structure, bush varieties require no external support like a trellis.
Pole lima beans have an indeterminate growth habit, continuously producing vines that can reach 6 to 12 feet. These vining types take longer to mature, typically 85 to 110 days, but offer a higher total yield over a much longer period, producing beans until the first frost. Though pole beans demand a support structure, they maximize yield in a smaller ground area by growing vertically.
Building Support for Vining Lima Beans
Pole lima beans produce vigorous vines, requiring a strong support system to manage the plant’s weight and maximize production. The structure should stand at least 6 to 8 feet tall to accommodate the full growth potential of the vines. It is beneficial to install the support at the time of planting to prevent later root disturbance. Suitable materials for trellises include:
- Sturdy stakes
- Wire fencing
- Cattle panels
- Specialized nylon netting
Trellising provides multiple benefits, including increased air circulation by lifting the foliage off the ground, which helps prevent disease. Vertical growth also makes harvesting easier, as pods are held at a comfortable height. Once the young vines begin to grow, they can be gently guided toward the support, and the tendrils will naturally grasp the structure to climb.
Basic Requirements for a Successful Lima Bean Harvest
Lima beans thrive in warm conditions and require full sun exposure, meaning at least 6 to 8 hours of direct light daily. They are tender annuals, so planting should only occur two to four weeks after the last expected frost. The soil temperature must have warmed consistently to at least 65°F, as planting too early in cold, wet soil can cause the seeds to rot.
The soil should be loose, well-drained, and rich in organic matter to encourage healthy root development. Lima beans prefer a slightly acidic to neutral soil pH, ideally ranging from 6.0 to 6.8. Consistent moisture is required throughout the growing season, particularly when the plants are flowering and setting pods. An inch of water per week, delivered at the base of the plant, is generally sufficient to prevent blossom drop and ensure the development of full pods.