Yard long bean, Snake bean
Vigna unguiculata subsp. sesquipedalis

Family: Fabaceae

What it is like

A climbing bean with long pods. The vines can be 3 m long. They normally twine around sticks. Dwarf kinds also occur. Leaves have 3 leaflets. The leaflets are oval and side leaflets are at an angle. Leaflets can be 2-16 cm long by 1-12 cm wide. The centre leaflet can have lobes near the base and the side leaflets can have lobes on the outer edge. The leaf stalks can be 2-13 cm long. The flowering stalks are in the axils of leaves. There can be few or several flowers. The flowers can be white, yellow or blue. Flowers are 1-3 cm long by 1-3 cm wide. Pods are long (up to 90 cm) and flexible. The seeds can vary between white to dark brown. They are oblong or kidney shaped. Seeds are 4-12 mm long by 2-6 mm wide. There are many named cultivated varieties.

There are about 150 Vigna species. They are mostly in the tropics. It is high in folates.

Where it is found

A tropical plant. Plants grow in coastal areas in the tropics from sea level up to about 300 m in equatorial regions. In Papua New Guinea it has been recorded up to 1,800 m above sea level. Seeds germinate in moist soil over 22°C. For growth, day temperatures between 25-35°C and night temperatures not below 15°C are required. It suits wet areas and cannot tolerate drought. Plants are day length neutral. They perform best under full sunlight but can tolerate some shade. It has a high water requirement for the full grown crop (6-8 mm per day). It can tolerate a wide range of soils with pH of 5.5-7.5. Seeds show no dormancy. It suits plant hardiness zones 10-11.

Countries/locations it is found in

Africa, Asia, Australia, Bougainville, Cambodia, Central Africa, China, Congo, Cook Islands, Cuba, East Africa, East Timor, Fiji, FSM, Guam, Guinea, Guinée, Guyana, Hawaii, India, Indochina, Indonesia, Japan, Kenya, Kiribati, Malaysia, Marquesas, Nauru, Pacific, Pakistan, Papua New Guinea, Philippines, Pohnpei, Rotuma, SE Asia, Singapore, Solomon Islands, South America, Sri Lanka, Suriname, Taiwan, Thailand, Timor-Leste, Tonga, Turkey, Türkiye, Tuvalu, USA, Vanuatu, Vietnam, West Africa, West Indies, West Timor

How it is used for food

Both the young pods and leaves are eaten. They can be steamed, stir-fried and used in other dishes. The ripe seeds can also be eaten cooked. The seeds can be sprouted and eaten.

It is a commercially cultivated vegetable. The most common and important bean in coastal areas of Papua New Guinea.

Edible parts

Seeds, leaves, pods, vegetable

How it is grown

Plants are grown from seed. Seeds germinate quickly (2-3 days) and plants grow rapidly. Flowering occurs after 5 weeks and harvesting of young pods can start 2 weeks later. Plants die after about 3-4 months. A spacing of 60 cm is suitable. Plants need sticks to climb up. Sticks about 2-2.5 m long are suitable. Often 5 or 6 seeds are sown around the one stick. Plants are often topped when growing too vigorously. It only grows as an annual bean so seeds need to be replanted each year. The pods need to be harvested every 2 or 3 days. Diseases get worse if the bean does not have sticks to climb. The damage by bean pod borer is less if snake beans are grown inter-cropped with maize.

Its other names

Local names

Asparagus bean, Bini balavu, Chang dou, Cheung kong tau, Denkane koa, Dolique asperge, Dow gauk, Fagiolo asparago, Fore-tali, Frijol grande, Habichuela china, Judia asparrago, Juuroku-sasage, Kacang panjang, Kouseband, Lobia, Makaraal, Pihns, Sanndaek treng, Sasage, Sitaw, Spargelbohne, Te bin, Thua chin, Tseng dou

Synonyms

Vigna sesquipedalis (L.) Fruw.; Dolichos sesquipedalis L.; Vigna sinensis (L.) Hassk. var. sesquipedalis (L.) Aschers & Schweinf.; [or Vigna unguiculata Sesquipedalis Group]