Fabaceae; native to China.

Germination: Sow indoors at 55-75° at a depth of 4 times the size of the seed. Germination will occur in 30-35 days. File, nick, or clip the hard seed coat before sowing. Soaking in hot water for 24 hours before sowing also aids in germination. Alternatively, seeds can be sown outdoors in spring or fall when the ground is cool, up to two months before first frost. Sow at a depth same as indoors and likewise perform mechanical scarification and soak the seeds.

Growth: Transplant when there are at least two sets of true leaves. Plant in full sun to partial shade in a slightly acidic or slightly alkaline, deep, rich, moist, well-drained soil. There is no need to fertilize with a nitrogen fertilizer as plants fix nitrogen and are vigorous growers. Wait to prune until after flowering, as pruning before will remove that year’s flowers. Do not attempt to transplant as they resent being disturbed. Very tolerant of drought, exposure, wind, heat, humidity, pollution, and low-fertility soils.

Appearance and Use: A twining, deciduous woody vine for use on trellises, arbors, porches, and any other support. Plants grow to 30 feet long and are covered in 12 inch racemes of 21/2 inch, sweet-scented, blue-violet flowers in May. The flowers appear before the light green, odd-numbered (7-13 leaflets) pinnate leaves.