Hyacinth bean, scientifically known as Lablab purpureus, is a species of bean belonging to the family Fabaceae. It is widely cultivated as a food crop in tropical areas like Indonesia, India, and some parts of Africa. These plants are climbers, making them a popular choice as screen on a fence or trellis, an ornate structure specifically designed to support climbing plants. In some parts of Africa, it is considered a traditional food because of its nutritional benefits and ability to promote food security and foster development in rural communities. The hyacinth bean thrives in well-drained compost soil under full sun exposure.
These annual plants are vines that produce purple seed pods and purple flowers. The hyacinth bean can grow 4 to 15 feet (1 to 5 m) in height. Its purple-green leaves can be either triangular or oval in shape. The flowers are shaped like peas and extend above the dense foliage.
All parts of the hyacinth bean plant are edible, especially the pods, flowers, and leaves. Eating the raw beans is not advisable due to their toxicity. While boiling, it is a must to change the water at least once to guarantee safety. It is important to note that prolonged boiling is required for the dry seeds because they contain highly concentrated amounts of cyanogenic glucosides, a dangerous chemical compound.
The hyacinth bean is widely used for culinary purposes. Mature seeds are fermented and pressed into a cake-like form for consumption or processed into tofu in many parts of Asia. Some people also eat the flowers both steamed and raw. Delicate young leaves are used in making salads and eaten raw, while the more mature leaves are cooked similarly to spinach. The root tubers are large and starchy, making them suitable for baking and boiling.
To propagate the hyacinth bean, the best method to use is seeding. The beans require ample support in order to climb. Growth of the plant can be enhanced by watering regularly and adding adequate fertilizers. The root system of this plant is not conducive to transplanting. Flowers are abundant, especially in the season of summer.
It is a natural occurrence for the hyacinth bean plants to be entangled because entanglement is a common trait of vines. To increase the circulation of light and air, some of the inner stems can be pruned. This practice can also encourage flowering when performed on a regular basis.
The fragrant flowers of the hyacinth bean attract hummingbirds, butterflies, and bees. These insects extract the nectar from the flowers and aid in pollination. Predator insects that are harmful to the plants can be discouraged by using pesticides and insecticides.