The annual flower, hyacinth bean--also known as Dolichos lablab--was common in American gardens; according to the University of Tennessee Institute of Agriculture, "this heirloom vine has been grown at Monticello for years." Hyacinth bean produces a twining maroon vine that reaches upwards to 20 feet, with dark green leaves veined in maroon. The blossoms are spikes of small lilac-colored flowers that bloom from late spring to early winter. The maroon bean pods form shortly after the flowers appear and can be harvested for the next season.
Select a site for the hyacinth bean that receives full to partial sunlight. The more sunlight this plant receives, the more it will flower.
Prepare the soil a month before planting. Dig up the flower bed, remove weeds, rocks, and other garden debris. Mix compost, decayed manure or leaves into the soil to enrich it.
Plant hyacinth beans after the last frost date. Plant the seeds 1 inch deep. Keep the soil over the seeds moist but not soggy. After the seedlings appear, thin the plants to 6 inches apart.
Place a plant support for the hyacinth beans to climb. This can be a trellis, a garden pergola, a fence or porch rail.