Heliotropium arborescens Seeds | Heliotrope
LATIN NAME: Heliotropium arborescens
COMMON NAME: Heliotrope, Cherry Pie, Garden Heliotrope
Plant Profile
Heliotrope is the cottage-garden plant whose dense purple clusters smell, to many noses, exactly like a fresh cherry pie. That scent won it a place on sunny patios and in conservatories for two centuries. The catch is less romantic: the leaves and stems carry pyrrolizidine alkaloids, compounds toxic to the liver, so this is a flower to enjoy by smell and sight, never by the cup.
The name heliotrope means ‘turn toward the sun’, and the flat-faced flower clusters do track the light through the day. In its Andean home the plant grows as an evergreen shrub, woody at the base, reaching a metre or more, with wrinkled, hairy, dark green leaves and coiled clusters of small purple or white tubular flowers.
The cherry-pie note is a blend of volatile compounds rather than the vanillin of real vanilla. The flower head releases a sweet, coumarin-like and benzyl-benzoate-style scent that people describe as vanilla, cherry, or almond. Breeders selected the strongest-smelling clones for the cut-flower and pot-plant trade, which is why modern garden forms smell richer than wild ones.
Garden heliotrope comes in shades from deep violet to pale lavender and white, selected over generations for compact habit and heavier scent. Breeders keep the colour and the perfume by choosing the strongest clones, since seedling strains wander back toward a looser, less fragrant wild look.
Because the best forms are clones, growers hold them by tip cuttings rather than by seed. A cutting keeps the exact flower colour and scent of the parent, which matters for a plant sold by its perfume. Seed is used only to breed new strains, and those seedlings are screened for smell before they reach the bench.
Pinch the growing tip when the plant is still young to force side shoots and a denser mound, which also loads the pot with more flower clusters. A bushy plant flowers along more stems and smells stronger near a seat than a single lanky wand.
Science & Biotechnology
The serious chemistry is the pyrrolizidine alkaloid load. These compounds damage the liver of mammals that eat the foliage and are the reason the plant is labelled poisonous to livestock and pets. The alkaloids concentrate in the leaves and are passed into any tea made from them, which is why old ‘heliotrope tea’ uses are now cautioned against in herbal references.
Species of Heliotropium are studied for alkaloids such as heliotrine and lasiocarpine, among the 1,2-unsaturated pyrrolizidine types that the body converts to harmful metabolites. The plant makes them as a defence against grazing, and their presence is a reliable chemical marker that separates heliotrope from the safer scented herbs it might be confused with. Because the dose that harms a grazing animal is far above what a brush past the flowers exposes a gardener to, the plant stays a safe ornamental so long as no one brews the leaf. The caution is aimed at internal use and at pets that might chew the foliage, not at the scent in the air.
Uses & Benefits
Use heliotrope for what it does best: scent and colour in a pot, a border, or a conservatory corner. It pairs with silver foliage and with other borage-family flowers, and the clusters draw pollinators when grown outside in warm weather. It is not a culinary or medicinal herb despite its sweet smell.
Set the plant where you brush past it, by a path or a seat, so the scent is released by touch. In cooler climates it is a summer container subject brought under cover before frost, which also keeps pets from nibbling the toxic foliage. In a mixed bed the purple clusters set off silver foliage such as lavender cotton and the grey leaves of other borage kin, giving a scent corner that works by day and by the evening seat. Grow it as a standard in a pot and the head of bloom becomes a small fragrant lollipop for a patio.
Growing from Seed
Sow the fine seed in warm trays on a light mix and keep it moist and bright. The seedlings are small and slow at first, so prick them out once they carry two or three true leaves and grow them on. Move the young plants to their final pot or bed when they reach about ten centimetres tall rather than on a fixed schedule.
In cold ground heliotrope is treated as a tender perennial and lifted or kept in pots under glass through the cold months. Trim it back, keep the mix just moist, and give bright light so it does not go leggy. A cool, airy corner beats a hot, dark room for holding the clone to spring.
Our Take
I grow heliotrope for the scent alone and keep it well away from the herb tea bed. Its borage-family kin make a good mixed border: the borage, the viper bugloss, and the comfrey share the same family feel.
Related Reading
Gardeners who grow Heliotrope often pair it with these related subjects: