Where Gulmohar grows in India

Gulmohar grows best in the frost-free plains and low hills of India, in both dry and moist areas, wherever it gets full sun and soil that drains well. ICFRE describes it as grown in the dry and moist regions of tropical India, up to the Himalayan foothills and as far north-west as the Yamuna, and notes that it is unsuited to places with heavy frost. Kew's checklist (via GBIF) lists it as introduced, not native, in India, including Assam, the Andaman and Nicobar Islands and the Himalaya; its only native home is Madagascar.

ICRAF gives its natural climate as roughly 700–1,200 mm of rain a year, from sea level up to about 2,000 m, and adds that it can be grown with less rain if it is watered.

• Grows well: the northern plains, central India, the east, the southern peninsula, the coasts and the islands, in open, sunny places. eFlora of India members record it as a common avenue tree in cities such as Delhi, Mumbai, Thane and Kolkata.
• With care: the dry north-west, including Rajasthan, where a young tree needs water through its first dry seasons and cover on frosty nights. Plants of Rajasthan records it as a cultivated tree around Kota, Bundi and Udaipur.
• Not suited: heavy frost, the higher Himalaya and shade. ICFRE notes that under shade it grows lean and lanky, and ICRAF says it flowers less in shade and in very wet places.

It accepts many soils if they drain well, and ICRAF says it prefers sandy soils. Avoid low spots where rainwater stands.

How to recognise Gulmohar

The easiest clue outside the flowering season is the leaf: very large, feathery and twice-divided like a fern, made of hundreds of tiny leaflets that fold up at dusk (Flowers of India).

• Leaves: Flora of China gives the whole leaf as roughly 20–60 cm long, with about 15–20 pairs of side branches, each carrying many small oblong leaflets only roughly 4–8 mm long.
• Flowers: large, bright scarlet to orange-red, roughly 7–10 cm across (Flora of China), with four spreading, spoon-shaped petals and one upright petal marked with yellow and white (Flowers of India). They come in big clusters near the ends of the branches, mostly April–June in north and central India.
• Pods: flat, woody and dark brown to almost black when ripe, roughly 30–60 cm long and 3.5–5 cm wide (Flora of China). ICFRE notes that they hang on the tree for a long time, often until the next flowers appear.
• Bark and shape: grey-brown, fairly smooth bark with many small dots, and a spreading, umbrella-shaped crown on long, nearly horizontal branches (ICRAF).
• Look-alike: the peacock flower or guletura (Caesalpinia pulcherrima), a related plant with similar red-orange flowers and feathery leaves, is sometimes called dwarf poinciana. Flowers of India notes that it stays a shrub-like treelet of roughly 3 m, with smaller flowers that keep coming through the year.