Withania somnifera Seeds | Ashwagandha
LATIN NAME: Withania somnifera
COMMON NAME: Ashwagandha
Plant Profile
Ashwagandha is a scrubby, grey-green shrub of dry disturbed ground, and it looks exactly like what it is: a survivor of hard use. The stems are covered in fine stellate hairs, the leaves are ovate and dull, and the whole plant has a rank, horse-like smell when bruised — the source of the Sanskrit name, ashwa for horse and gandha for smell. The flowers are small, greenish and bell-shaped, and they are followed by papery calyces that swell into lanterns around a small red berry. It grows from the Mediterranean through Africa and Arabia to India, usually on overgrazed land, roadsides and field edges, and it is treated as a weed in some of those places and as a crop in others. A good plant reaches a metre and a half in a season and flowers within three months of sowing.
Science & Biotechnology
The active constituents are the withanolides, a family of steroidal lactones built on an ergostane skeleton, of which withaferin A is the most studied. They are concentrated in the root but present in the leaf as well, and the leaf material is chemically different enough that the two should not be substituted for one another. Human trials have mostly used standardised root extracts at 300 to 600 mg a day in adults reporting stress, and the pooled results point to modest reductions in perceived stress and in serum cortisol, with sleep scores improving in some studies and not others. Safety data are reasonably reassuring at those doses, but case reports of liver injury exist and the herb is contraindicated in pregnancy; it can also raise thyroid hormone levels, which matters for anyone on replacement therapy. It is not a ginseng, despite the marketing, and its chemistry has nothing in common with Panax.
Uses & Benefits
The root is the crop. It is dried, sliced and ground, and sold as a powder, a decoction or a standardised extract; the leaf is used in some preparations but is a different material with a different profile. In the garden the plant is a useful, drought-hardy filler for a hot dry border, where its grey foliage and red berries carry it through the summer, and it self-sows readily on bare ground once established. It is also grown as a short-term rotation crop in warm regions, sown after a cereal and lifted for the root after six to eight months. The berry is not the source of vegetable rennet — that is Withania coagulans, a different species — and the two are regularly confused in the supplement trade, which is one more reason to buy by Latin name.
Growing from Seed
Sow in spring at 20 to 25 °C on a free-draining compost, barely covering the seed, and keep it evenly moist; germination is fast, usually within two weeks, and the seedlings are vigorous. Grow them on in full sun, in pots that are not too rich, because soft growth makes a floppy plant. Plant out after the last frost, in the poorest, best-drained ground you have, and water only to establish. The plant sets seed freely and will usually give you a volunteer population in the second year. In a cold climate treat it as an annual and lift the roots in autumn, because frost kills the top growth and often the crown. Harvest the root at the end of the first season, wash it, split it lengthways and dry it fast.
Our Take
A useful crop and a genuinely interesting plant, but the medicinal case rests on modest effects and a real, if uncommon, liver risk.
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