cestrums

Cestrum is a genus of flowering plants in the nightshade family, Solanaceae, comprising about 150 species of evergreen shrubs and small trees native to tropical and subtropical regions of the Americas. The genus is valued in horticulture for its glossy foliage and clusters of tubular flowers, which are often intensely scented and attract pollinators such as hummingbirds and moths.

Leaves are simple, alternately arranged, usually lanceolate to oval. Flowers appear in terminal or axillary panicles and vary in color by species, including white, cream, yellow, orange, red, or purple. Many cestrums have strongly scented flowers, especially at night in species like Cestrum nocturnum, commonly called night-blooming jasmine, though it is not a true jasmine.

Examples and cultivation: Cestrum nocturnum is widely cultivated as an ornamental hedge or boundary plant in tropical and subtropical climates; Cestrum parqui, or green cestrum, is native to southern South America and used as hedging but is considered toxic and potentially invasive in some environments. Some varieties have become invasive outside their native range, displacing local vegetation and posing management challenges.

Toxicity and cautions: All parts of cestrums contain alkaloids and can be poisonous if ingested by humans or animals. Handling is usually not hazardous, but contact dermatitis is possible in sensitive individuals. Because some species are invasive and toxic, planting cestrums in appropriate settings and monitoring spread is advised.

Horticultural notes: They generally prefer full sun to partial shade, well-drained fertile soil, and moderate irrigation. Pruning after flowering helps maintain shape and vigor. They may be short-lived in extremely cold conditions but can regrow from base in milder climates.