If you’re in the planning mode for next spring and you’re looking for a new ornamental to add to your landscape, look no farther than Hyacinth Bean. This annual vine is great for vertical interest in the landscape, and it never fails to draw admiring comments. It’s an economical vine to grow by seeds, and it’s fast growing and quickly can produce dense foliage for a beautiful privacy screen if given the support to climb.
There are several botanical names used synonymously for this vine: Dolichos lablab, Dolichos purpureus, and Lablab purpureus. Common names for the plant include: Egyptian Bean, Indian Bean, Lablab, Pig-ears (for the leaf shape – broad, oval and pointed), and Bonavista Bean.
Lablab is a vigorous grower that needs a structure such as an arbor or trellis to climb. The support structure needs to be sturdy and at least 10 – 12 feet tall; the vine can reach 15 feet or more. The vine is typically grown as an annual, but in climate zones 9 – 11, it will come back each spring after dying back during the winter. Native to tropical Africa, this twining vine with dark green, course leaves, purplish stems and long clusters of pea-shaped, light purple flowers is extremely attractive. As the flowers die in the latter part of summer, seeds begin to be produced in a flat, broad, purple to maroon pod that is similar to a snow pea. As the season progresses, the pods continues to plump up and elongate, and they create a showy display as the rich purple color contrasts beautifully with the dark green foliage. The plant will continue to give beauty until the first frosts.
Hyacinth bean is a food and forage crop in some parts of the world. It is a popular vegetable in India, Asian countries, West Africa, Japan, and the Caribbean, using both the immature pods and the dried beans. Mature Hyacinth beans are edible, but they must be prepared by boiling to remove the toxicity before eating. Cyanogenic glycoside is the toxic chemical contained in the mature pods and seeds. If eaten in large quantities without proper preparation, Lablab is poisonous. Typically in the United States, this vine is grown for its ornamental value. Hyacinth bean cut stems are unique and lovely in cut flower arrangements, and the vines are grown for the cut flower market. The cut stems have a long vase life of 10 days or more.
Start Hyacinth bean seeds directly outdoors once frosts have passed and the soil temperature has warmed to 60°. The flower seeds can also be started indoors in small pots 4 to 6 weeks before the last spring frost. Some gardeners recommend soaking the Lablab seeds 24 hours before sowing. Smaller plants transplant more successfully than larger, more mature plants that have started to vine. Hyacinth bean vine can be grown in well-drained soil and in full sun. It tolerates acidic, low fertility soils and drought, but in fertile soil with even moisture, the growth is more vigorous. Fertilize the vines each month to promote the best blooms, but avoid fertilizers high in nitrogen. Lablab will often reseed if the pods open and drop their seeds, but this vine is not considered to be an aggressively invasive plant. The Lablab seed can also be harvested and saved for next year’s plants.
Another benefit provided by Lablab is that it is a legume and can be grown as a nitrogen-fixing green manure adding organic matter and improving soil structure and quality. Lablab can be grown specifically as a cover crop to suppress weeds and provide soil erosion control.
For beautiful, fragrant flowers, showy seed pods and as an attractant to butterflies and bees, consider growing this wonderful vine next year. You won’t be disappointed with its beautiful display and other great benefits!
By Kimberly Bell