4-40 years, depending on cultivar.
Rapid, usually 10' a year. Can grow 20' a year in favorable conditions.
Small, yellow-white, sweetly fragrant, clustered. The flowers and buds are
edible, but act as a diuretic in large amounts.
Twice a year or more in non-freezing regions. Late fall to early winter and
late spring to early summer.
Years before fruiting:
Fruits first year. Flowers appear 8 months after planting.
A very long, slender, ribbed pod containing round, edible seeds.
Young small seedpods can be used raw in salads or cooked like green beans. Older green
pods, with the outer stringy coat scraped off, need longer cooking and have an
Dried mature seeds are dark brown, round, with 3 white wings and are composed of 38-40%
oil. Pressing the seeds produces a non-drying, clear, odorless oil called Ben Oil, used for
cooking and as a machine lubricant.
The inedible seed cake remaining after oil extraction is used as a plant fertilizer.
For some cultivars, the fruit is bitter and inedible in later years, causing them to
be grown as an annual.
Months for fruit to ripen:
2-4, depending on cultivar.
Storage after harvest:
Store mature pods in a dry space.
The green, oval leaflets are edible. Used raw in salads, they taste
similar to watercress or radicchio. Lightly cooked and added to chili, omelets, stew
or soup, they taste like a nutty flavored spinach. While they contain oxalates, the oxalates
are non-soluble, cannot contribute to kidney stones, and provide flavor without impairing health.
The leaves have seven times the Vitamin C of oranges, four times the vitamin A of
carrots, three times the potassium of bananas, at least twice the calcium of milk and
two times the protein of yogurt.
The tree provides light to light-medium shade.
No thorns. New stems are slender and brittle, but become stronger in succeeding
years. The trunk, with whitish-gray, corky bark, becomes more cold hardy with age. The wood
is too weak for construction but is good firewood. A blue dye can be made from the sap.
Large taproot. The thick roots are edible and are a substitute for horseradish.
The tree is prone to root rot in waterlogged soil.
Cultivars of Note:
'PKM-1' Provides the largest yield of leaves and seedpods
in the shortest time period. Grown as an annual and harvested roots and all.
Developed by Periyakulam Horticultural College and Research Institute, Tamil Nadu.
'PKM-2' Provides more lateral branching for better leaf access,
fatter seed pods with fewer seeds and a longer lifespan than PKM-1. Requires more
water. Also developed by Periyakulam Horticultural College and Research Institute.
Attracts bees, butterflies, mammals.
Toxic / Danger:
The bark is mildly poisonous to humans. Eating more than two dried seeds
can induce a laxative effect.
Southern foothills of the Himalayas in northwest India. In use more than 4000 years.