Cestrum nocturnum Seeds | Night-blooming Jasmine
LATIN NAME: Cestrum nocturnum
COMMON NAME: Night-Blooming Jasmine
Plant Profile
The flowers are greenish white to cream, produced in dense clusters at the ends of the branches, and each corolla is a slender tube two to two and a half centimetres long that splits into five sharp triangular lobes. The tube opens in the evening; by day it is closed and dull. Inside, the five stamens sit high in the tube, each filament carrying a small erect tooth below the point where it joins.
The perfume that makes the plant popular also makes it unpopular with some people. Headache, nasal irritation and difficulty in breathing have been reported by people with respiratory sensitivity who were shut in a room with a flowering bush, and chlorogenic acid, which occurs in several species of the genus and is a known sensitiser, is one candidate for the effect. Ventilation is the whole answer indoors.
The species comes from Mexico, Central America and the West Indies, and cultivation has carried it much further than that. It is grown through the tropics and subtropics for its scent, and it has naturalised in southern China, southern Africa, Australia, New Zealand, the southern United States and a long list of Pacific islands, from Hawaii and Guam to Fiji, Samoa, the Cook Islands and Tonga.
Where it escapes, it is not a mild garden escapee. The shrub forms dense, impenetrable thickets in moist forest, on forest margins and along streams, shading out the native understorey and preventing regeneration, and it is classed as a serious weed in parts of New Zealand and as a high-risk species on several Pacific islands. It spreads by abundant bird-dispersed seed and by root and stem fragments.
Science & Biotechnology
The true jasmines belong to the olive family, with flowers built on a different plan and fruit that splits into two halves. This plant is Solanaceae from the root up: tubular corolla, five stamens tucked inside the tube, and a berry. Its count of chromosomes is sixteen, and it is self-compatible, which is one reason a single bush in a garden can set a crop of seed without any help.
Because of that abundance, research has looked at turning the plant’s chemistry against pests. Extracts have shown larvicidal activity against the yellow fever mosquito in laboratory tests while causing no mortality in fish, and other work has examined the effect of sublethal doses on fish blood. These are screening results from a weedy shrub, not a recommendation to brew a garden spray from a toxic Solanaceae.
Uses & Benefits
The fruit is a white, hard or juicy berry about a centimetre across, ripening from green, and it is not food. Solanaceae alkaloids are the general reason; a case is recorded of a young child who ate green berries repeatedly and became ill with vomiting, diarrhoea and bleeding, and livestock deaths have been reported where the shrub has escaped into pasture. Treat every part as toxic.
Growing from Seed
Distilled flower oil of the species is dominated by phenylethyl alcohol, which is also a main component of rose oil, with benzyl alcohol, eugenol, benzaldehyde, the long-chain hydrocarbons eicosane and tetracosane, and caryophyllene oxide making up much of the remainder. The blend is released when the temperature falls and the air stills, which is why a plant is at its most powerful on a warm night after rain.
Sow the cleaned seed onto a light, sandy compost of equal parts peat, sieved leaf mould and coarse sand, press it in and cover it very lightly, then keep the pan warm and humid in partial shade. Prick the seedlings out at the two or three true-leaf stage into individual pots, and grow them on in a bright, frost-free place, shifting them into larger containers as the roots show at the drainage holes.
In a frost-free climate the shrub can be planted out and lightly pruned in early spring to keep it dense; elsewhere it belongs in a large pot that is moved under cover before the first frost. It tolerates most soils, likes plentiful water in growth and less in winter, and can be cut back hard if it outgrows its corner. Watch for red spider mite and whitefly under glass.
Our Take
Mine lives in a pot that goes into the porch each autumn, which is just enough to keep it alive and no more than enough to keep it scented. The genus has a dark cousin that is treated as a pasture weed in Australia, the green cestrum, and if what you actually want is a true jasmine then the Arabian jasmine is the honest article. For another Solanaceae whose scent belongs to the evening, look at the angel’s trumpet.
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