Cestrum parqui Seeds | Willow-leaved Jessamine
LATIN NAME: Cestrum parqui
COMMON NAME: Willow-leaved Jessamine
Plant Profile
Willow-leaved jessamine is a fast-growing shrub of the nightshade family from Chile and Argentina, growing two to three metres with long, narrow, willow-like leaves and loose clusters of tubular, greenish-yellow flowers. The flowers open in the evening and release a heavy, sweet perfume that carries a long way, attracting moths and, in gardens, more than a few gardeners with a torch. Purple-black berries follow and are eaten by birds. Every part of the plant is toxic, and it has killed cattle that grazed the regrowth after fire. It spreads by seed and by suckering, and in Australia and South Africa it has become a serious invasive weed of riverbanks and disturbed ground. In its native range it is a coloniser of scree and river gravel.
Science & Biotechnology
Cestrum parqui contains atropine-like tropane alkaloids and, more importantly, the diterpenoid carboxyparquin, which causes acute liver necrosis in grazing animals. The plant is dangerous in a way that is easy to underestimate: it is unpalatable when green, but stock eat the dried leaves in hay or the fresh regrowth after fire, and deaths follow within days. The night-time scent is produced by benzenoid compounds released on a circadian rhythm, peaking after dark, and it is one of the strongest in the genus. The species is self-compatible and sets abundant seed, which birds distribute, and the seed bank persists for years. Its invasiveness outside its native range is a consequence of that combination: fast growth, heavy fruiting, bird dispersal, and unpalatability to most herbivores.
Uses & Benefits
The plant is grown for its scent, usually near a terrace or a window that is open in the evening, and it is one of the most fragrant shrubs for a warm climate. It is also used as a quick screen or a filler in a new garden, since it grows fast and tolerates poor soil. In Chile it has a place in folk medicine as a febrifuge and a wound wash, but the toxicity makes any internal use dangerous. It should never be planted where livestock graze, and it should not be composted if there is any chance of contamination. In frost-prone gardens it dies back to the base and regrows in spring, which keeps it compact but delays flowering.
Growing from Seed
Sow in spring at twenty degrees on a free-draining mix, one centimetre deep, and keep moist; germination takes two to four weeks. The seedlings grow fast and can be planted out after the last frost. Choose a sunny, sheltered spot with well-drained soil; the plant tolerates poor ground and drought once established. Water through the first summer, then only in long dry spells. Cut back hard in late winter to keep it bushy and to control suckers, and remove self-sown seedlings before they establish. In cold climates, grow it in a large pot and move it under cover for winter, where it will still flower.
Our Take
Grown for a scent that arrives after dark, and dangerous to cattle. Keep it away from stock and deadhead it hard.
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