Vicia faba Seeds | Broad Bean
LATIN NAME: Vicia faba
COMMON NAME: Broad Bean
Plant Profile
Vicia faba is the broad bean of the vegetable garden, and it is one of the oldest cultivated plants, grown for seed since the Neolithic. The plant is upright and stiff, a metre or more tall, with square stems, pinnate leaves and white flowers with a black mark on the wing. The pods are thick and downy, and the seed inside is flat and green or brown.
The species is native to the eastern Mediterranean and to south-western Asia, and it is grown in cool seasons throughout the temperate world. It is the only species in its genus that is cultivated on a large scale, and it is used as a green manure, as a fodder crop and as a protein food for people. In China it is one of the main winter crops of the Yangtze valley.
Science & Biotechnology
The seed contains phytohaemagglutinin and other lectins, which are destroyed by cooking, and it also contains vicine and convicine, two glycosides that cause favism in people with glucose-6-phosphate dehydrogenase deficiency. Favism is a haemolytic anaemia that can be severe, and it is the reason broad beans are eaten with caution in Mediterranean populations where the deficiency is common.
The plant fixes nitrogen through rhizobia, and it is one of the best nitrogen-fixing crops for cool climates, adding up to two hundred kilograms of nitrogen per hectare. It is also sensitive to chocolate spot, a fungal disease that thrives in wet weather, and to rust, and it is one of the crops that suffer most from a wet spring.
Uses & Benefits
The seed is eaten fresh, dried and ground into flour, and it is used in dishes from Egypt to China, including ful medames and the fermented black beans of Sichuan. The plant is grown as a green manure and as a fodder crop, and the straw is used for bedding.
In traditional medicine the pod is used as a diuretic and the seed as a tonic, and the flower is used for skin complaints. The plant is also grown as an ornamental for the flowers, which are handsome in a row, and it is used in companion planting for its nitrogen.
Growing from Seed
Sow in autumn or in early spring, two to three centimetres deep, in a double row. Germination is in one to two weeks, and the plant is hardy to about minus eight when young. It needs a long, cool season, since heat stops pod set.
The plant wants full sun, a deep, moisture-retentive soil and support in a windy site. Pinch out the tops when the first pods set, to deter blackfly and to concentrate the crop. Do not eat the seed raw, and avoid it if you have G6PD deficiency. In a wet winter, sow on ridges to keep the roots out of standing water.
Our Take
An ancient protein crop and a first-class nitrogen fixer, with a seed that is food for most and a hazard for a few.
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