Tsimbande, known in English as the Bambara groundnut (Vigna subterranea), is a major food for the Luhya community in Western Kenya, particularly in Kakamega County. It is grown to a lesser extent by the Giriama and Akamba people in southeastern Keny, and by the Luo, neighbors of the Luhya. Tsimbande are grown in relatively poor soils (usually sand or loam) in hot regions, at elevations up to 1,550 meters. They are planted in rows or randomly, normally after the maize harvest (August), and harvested 4-5 months later (December-January). Chemical fertilizers need not be applied to areas where tsimbande is cultivated because the crop fixes nitrogen (it is a legume). Harvesting is usually done by uprooting or digging out the entire plant and picking the individual pods, which grow just below the soil surface. The pods are approximately 1.5 centimeters long, round or slightly oval shaped, and may be wrinkled. Each pod contains one or two seeds, the color of which can be black, dark brown, red, white, cream, or a combination of these. The pods are often sundried and then threshed and winnowed to obtain the seeds.
The seeds of the Bambara groundnut are crunchy and have a strong, beany flavor. In adition to being eaten raw, they are cooked with maize or on their own and then mashed, fried, and made into a stew. They can also be grilled. Tsimbande are normally consumed when vegetables are in short supply. The seeds can also be dried, pounded to remove the seed coat, winnowed, and boiled until they are cooked through, then stirred until smooth and served with rice or ugali. Among the Luhya, dry tsimbande can either be pounded or ground and the resulting meal made into a stew or sauce to be served with leafy vegetables. Unshelled pods are boiled, fried, and served with potatoes, banana, or ugali.
The Bambara groundnut is an African indigenous crop. It is the third-most-important grain legume (i.e. pulse) in the African lowland tropics after the peanut (Arachis hypogaea, commonly referred to as the groundnut) and the cowpea (Vigna unguiculata). They are an especially important traditional food among the Luhya. A number of decades ago, tsimbande were considered important food during droughts and famine. They have a high ceremonial value and are prepared for people to eat during funerals and naming and bridewealth ceremonies. The seeds are mainly produced for home consumption but sometimes women sell tsimbande to individuals or in the informal markets of the area.
In Kenya, the Bambara groundnut is considered an orphan crop. Its production in Kenya, like that of many other traditional crops, has been declining for the past few decades. Despite the fact that tsimbande is still considered a delicacy in the Luhya community, current levels of production in other communities are low and decreasing. Tsimbande is at risk for a number of reasons: It is difficult to harvest, cooking the dried nuts takes a long time compared to other nuts (thereby requiring more fuel and water to process), and it is hard to mill due to its fibrous shells. Additionally, it is usually given less value and priority in land allocation because it is grown by women.