Where the Ashoka tree grows in India

The true Ashoka grows wild in the warm, moist forests of India and its neighbours, and is planted wherever it can get enough water and some shade. Kew's World Checklist (read via GBIF) gives its native range as India (including Assam and the eastern Himalaya), Nepal, Bangladesh, Myanmar and Sri Lanka, and lists it as introduced in the Andaman and Lakshadweep islands. Vikaspedia says it is naturally most frequent in south India, Odisha and Assam, and also grows in the central and eastern Himalaya up to about 750 m. eFlora of India has records from more than 20 states, from Kerala to Punjab, though many of these will be planted trees.

It is a tree of high rainfall. The National Medicinal Plants Board's southern facilitation centre gives roughly 1,500–4,000 mm of rain a year and 19–25 °C as its climate. Vikaspedia says it grows well in moist tropical areas with well-spread rain and thrives in partly shaded places, and Useful Tropical Plants describes it as a tree of lowland evergreen forest that grows best in deep, moist soil, especially near water.

How it suits each part of India:

• Grows well: the west coast and Western Ghats, the wetter parts of the southern peninsula, the east (such as Odisha and West Bengal), the north-east and the Himalayan foothills (our summary of Vikaspedia, the ICAR-DMAPR study and eFlora of India records).
• With care (our assessment): the northern plains and central India. Water it through every dry season, give a young plant shade from the harsh afternoon sun, and protect it in its first winters.
• Only in a sheltered, irrigated spot (our assessment): the dry north-west, for example around Jaipur, where the rain is far below what the tree is used to. Plant it in a courtyard, on the east side of a wall or building that blocks the afternoon sun, or under the light shade of taller trees, near a water source, and plan to water it every dry season, not just in the first year.

How to recognise the Ashoka tree

You can recognise the true Ashoka by its long compound leaves, its limp copper-red new leaves and its dense clusters of orange-to-crimson flowers, which have no petals. Details from eFlora of India, Vikaspedia and Flowers of India:

• Leaves: compound, with 4–6 pairs of long, pointed leaflets (eFlora of India); Vikaspedia gives the whole leaf as roughly 30–60 cm long. Young leaves are soft, red and limp and hang down (Flowers of India).
• Flowers: small, fragrant and tube-shaped, in tight clusters along the branches and twigs. They have no petals: the coloured part is the calyx, yellow at first, then orange and crimson, with long stamens sticking out (eFlora of India, Flowers of India).
• Flowering time: in a 2012–2015 study at Anand, Gujarat, ICAR-DMAPR recorded flowers from the end of December to May, most in February–March. eFlora of India notes a peak in early April in Delhi and February–March in Kolkata, and Flowers of India says a few flowers can appear through the year.
• Pods: flat and leathery, roughly up to 25 cm long and 6 cm wide, with 4–8 seeds (eFlora of India); Vikaspedia describes them as dark when ripe.
• Bark: smooth and grey-brown (Flowers of India); on old stems it is dark, often with pale patches of lichen (Vikaspedia).
• Shape: a small evergreen tree with a compact, rounded crown (Flowers of India).
• Look-alike: the Mast tree, which many people and nurseries call "Ashoka" (see below).

True Ashoka or Mast tree?

Most trees called "Ashoka" along north Indian roads are the Mast tree, not the true Ashoka. eFlora of India says the Mast tree is commonly but wrongly called Ashoka in many parts of India. The quickest test is the leaf.

	True Ashoka (Sita Ashok)	Mast tree (roadside "Ashoka")
Scientific name	Saraca asoca	Monoon longifolium (also sold as Polyalthia longifolia)
Family	Fabaceae (pea family)	Annonaceae (custard-apple family)
Leaves	Compound, with 4–6 pairs of leaflets	Simple, long, narrow, with wavy edges
Shape	Small tree with a rounded crown	Tall, narrow column (a spreading form also exists)
Flowers	Orange to crimson clusters	Pale green and star-like
In tradition	The Ashoka linked with Sita and the Ramayana (Patna Zoo) and the Asoka of Ayurveda (Vikaspedia)	Took the name Ashok in north India; Flowers of India calls Sita Ashok the "real" Ashok

A study in the Indian Journal of Natural Products and Resources calls Mast tree bark the most commonly used adulterant of Ashoka bark in the herbal trade. If a nursery offers a tall, narrow "Ashoka", it is the Mast tree; read about it on our Mast tree page.