Vicia benghalensis aka Purple Vetch

Vicia benghalensis, or purple vetch, belongs to the pea family, Fabaceae. It is native to Madeira, southern Europe, and north-west Africa. Its range includes parts of France, Spain, Portugal, Italy, and Greece. It also occurs in Algeria, Morocco, and Tunisia. It is not native to Britain or Ireland. There, records place it along field edges and on waste ground. Kew places the species in temperate climates.

Purple vetch is a climbing plant that can be annual or perennial. It grows fast and reaches about 2 feet [0.6 metres]. The supplied sources give no mature spread. They also lack species-level details about its leaves, stems, and fruit. The flowers have both male and female organs. Insects pollinate them, and the plant is also self-fertile. The evidence gives no flowering season for this species.

Grow it in soil that drains well but stays moist. It accepts sandy, loamy, and clay soils. It also tolerates mildly acid, neutral, and mildly alkaline conditions. A sunny site suits it when soil stays moist throughout growth. Where moisture is less reliable, light shade is the better choice. The sources list cultivated beds as a garden setting. They give no hardiness zone or minimum winter temperature. For sowing, soak seeds in warm water for 24 hours. Sow them directly in their growing site in spring or autumn.

Its main recorded garden use is as a green manure. Fast growth helps it cover soil and hold back weeds. It also produces a useful amount of plant material. Bacteria live in nodules on its roots and fix nitrogen. The plant uses some of this nitrogen for its own growth. Nearby plants may also gain some benefit from this partnership. The flowers provide a dye with a green-blue shade. These uses give it value beyond its place in planted beds.

Plants For A Future lists no known food or medicinal uses. It gives both uses a rating of zero out of five. That source also reports no known hazards for the species. This does not establish that all parts are safe to eat. The supplied evidence gives no specific pest or disease problems. Plants For A Future does not flag it as weedy. Its recorded role in weed control refers to suppressing other plants. It does not, by itself, establish how the vetch behaves everywhere.