For gardeners who can hardly wait to start the vegetable garden in spring, broad beans (Vicia faba) are very interesting. Their seeds germinate at just a few degrees above zero and the care of the plants is uncomplicated. After four to five months it is time to harvest.
The annual broad beans are legumes, which also include peas and lentils. The botanical genus name Vicia indicates that the species – unlike the common beans (Phaseolus) – is counted among the vetches. Broad beans (also called broad beans or broad beans) are rarely available fresh in the trade. They are mainly grown for their large, protein-rich seeds, which are encased in the typical pods. The variety is large and above all colourful: the bean colours can be white, beige, brown, purple and black.
Broad beans have played an important role in nutrition for thousands of years. In Mediterranean and Arabic cuisine, they are an integral part of many dishes – in the Arab world, they are used to make falafels, among other things. In the context of the vegan lifestyle, however, they are also becoming increasingly popular in our latitudes – especially as the plants thrive wonderfully in the local climate. The seeds can be eaten when half or fully ripe. They can also be dried and stored very well.
There are two subspecies of Vicia faba. The variety Vicia faba var. major is often cultivated for human consumption. Another subspecies, Vicia faba var. minor, is often used as cattle feed. This is where the name “broad beans” comes from. A fibre obtained from the stalks is also used to make soap.
The legumes can reach a height of up to two metres. Their square, hollow stems are stiff and therefore quite sturdy. The fragrant butterfly flowers appear in the leaf axils from May. They are usually white and show a characteristic black spot on the wings. They give rise to thick, waxy pods that can reach a length of 20 centimetres.
The suitable location and soil
Broad beans love a climate with high humidity. That is why they are often grown near the sea, where they even thrive in salty soil. In the garden, a sunny location sheltered from the wind is recommended. Ideally, the soil should be loamy and well-drained.
When and how are broad beans sown?
Broad beans like the cool, damp weather in spring. So you can sow them as early as the end of February, as soon as the ground is no longer frozen. As a general rule, the earlier the seeds are planted, the higher the yield. Summer heat and drought, on the other hand, are not well tolerated by the butterfly plants. They then drop their flowers and the yield decreases. In addition, high temperatures increase susceptibility to the black bean aphid.
The beds are prepared with mature compost before sowing. The plants need this initial fertilisation – even though in the longer term they will gain another source of nitrogen through a symbiosis with nodule bacteria that fix atmospheric nitrogen.
Sow the large, angular seeds five centimetres deep at a distance of about 20 centimetres. A row spacing of 40 centimetres leaves enough room for development. It is more space-saving to sow one row of broad beans per bed and combine them with other vegetable crops. From March, for example, spinach and early carrots can join them, and from May early potatoes.
Growing broad beans in advance
In harsh regions where the winter lasts a long time, broad beans can be grown in a cold, frost-free greenhouse or cold frame. Transplanting, however, is somewhat laborious, which is why this method is only recommended for smaller beds. Advantages of this method: The pods ripen earlier and the plants are more likely to be spared from the black bean aphid.
It is best to sow the plants individually in small pots from the end of February. This way there is no need to prick them out later. Four weeks later, the plants can already move to their final location.
The young bean plants can survive temperatures as low as minus six degrees Celsius without damage. If the thermometer drops even lower, you should cover them with double fleece.
During the flowering period broad beans are quite thirsty, so you should water them regularly. Tall varieties can be supported with sticks. Until the crop is closed, you should hoe regularly around the beans. This aerates the soil and keeps the weeds back. Mounding the plants also increases their stability.
Harvest broad beans
The immature beans can be harvested from the end of May with the first early potatoes. Pick the pods when the seeds inside are plump and clearly visible. Then break the pods open lengthwise, only the irregularly shaped seeds end up on the table. Broad beans should be eaten young, when the pods are still tender. The bean seeds are then pale green or milky white. However, the seeds are difficult to digest raw. They are therefore blanched briefly in salt water.
If you want to dry the beans, you can let them ripen directly on the plants. Important: The seeds must be completely dry for storage so that no rotting occurs. After hulling, it is best to lay them out on cloths in the sun for a while.
Broad beans leave the bed almost weed-free and enriched with nitrogen in July. The roots can remain in the soil. This makes the buttercups a good precrop for winter cabbage and endives. A few plants can be left at the end of the row for seed harvesting.
Broad beans are not a treat for everyone. Fava bean disease (favism) is a hereditary enzyme deficiency that leads to chronic anaemia and haemolysis if the raw seeds are consumed excessively or the pollen is inhaled. In Central Europe, about 0.5 percent of the population is affected.
The variety of broad beans
The seeds of many varieties turn brown after cooking, while others remain appetisingly white or green. This characteristic is closely related to the flower colour.
Broad beans with white flowers and a black throat often produce seeds that turn brown when cooked. They are quite tender and intense in flavour, such as the varieties 'Early White Sprouts', 'Piccola' and 'Aguadulce'. The seeds of representatives with pure white flowers, on the other hand, remain white or green even after the cooking process. This includes the variety 'Triple White'. A light purple hint on white flowers indicates the variety 'Rotsamige', whose beans are red-purple when fully ripe. Rarer are varieties with purple or red flowers, for example 'Crimson'. They usually have green seeds.
Tip: If you want to save seeds for next year, you should only grow one variety. This way, the special characteristics are preserved. This is because cross-pollination often occurs.
Profile: Broad beans
Vegetable family: Butterfly family, related to garden beans, peas, soybean Soil: medium to heavy, nutrient-rich, deep, pH 6.5 to 7 Sowing: from the end of February to May Sowing depth: 5 centimetres Harvest: from the end of May Storage: fresh pods keep for a few days in the refrigerator Crop rotation: cultivation break of four years after butterfly vegetables, good preceding crop for strong eaters, clears the bed early for winter vegetables Fertilising: Weak growers, start fertilising with 1-2 l compost/m² for sowing. Common pests: black bean aphid, slugs and snails Tried and tested varieties: 'Triple White', 'Hangdown Green', 'Piccola', 'Crimson', 'Early White Sprouts', 'Perla'.