Neem is a fast-growing evergreen tree in the mahogany family, native to the Indian subcontinent and naturalized across tropical and subtropical regions. It is the primary commercial source of neem oil—a broad-spectrum biopesticide extracted from its seeds—and is central to South Asian agriculture, horticulture, and traditional medicine.
Under good conditions the tree reaches 40–65 feet in 15–20 years, forming a dense canopy effective for shade in hot climates. It tolerates drought, heat, and poor soils once established, but cannot survive frost; temperatures below 35°F cause dieback and sustained freezing kills the tree. The root zone releases allelopathic compounds that can suppress germination of some nearby plants. Prune young trees to a single central leader; neem tolerates hard cutbacks and resprouts readily. In zones below 10, large container-grown specimens can be overwintered indoors in full sun.
Azadirachtin, concentrated in the seeds, is well-documented as an insect growth regulator and antifeedant and underpins OMRI-listed organic pesticides used globally. In Ayurvedic practice, bark, leaves, and oil are applied to skin disorders, fever, and oral hygiene—chewed neem twigs function as antibacterial toothbrushes across South and Southeast Asia. Young leaves appear in South Indian and Southeast Asian cooking, used in chutneys, stir-fries, and rice dishes despite their pronounced bitterness.
Growing it indoors up north? See the indoor care guide — light, water, and the rhythm that keeps it flowering as a houseplant.