Hyacinth Bean

Treat hyacinth bean like the vigorous tropical climber it is. Wait until your soil has truly warmed — at least 65°F — before direct sowing, because seeds rot in cold wet ground and the plant won't make any real progress until nights stay warm. Nick or soak the hard seed coat overnight to speed germination, then plant an inch deep at the base of a strong trellis, fence, or arbor. The most common mistake gardeners make is overfeeding: as a legume it fixes nitrogen, so a heavy hand with fertilizer gives you a wall of leaves and almost no flowers or pods. Give it lean-to-moderate soil, full sun, and something tall to climb, and it will reward you well into fall right up until your first frost knocks it back.

This plant has a long history across Africa and Asia as a food crop, though it comes with an important caveat. The young tender pods and shoots are eaten cooked in many cuisines, and the dried mature beans are a traditional pulse, but raw or undercooked mature beans contain cyanogenic compounds and must be boiled thoroughly — typically with at least one change of water — to make them safe. In traditional medicine the boiled seeds have been used as a digestive remedy and tonic, and the plant features in folk treatments across its native range. For most home gardeners it earns its keep as an edible, nitrogen-fixing summer climber, but always cook the beans properly and never eat them raw.