The term “heliotrope” refers primarily to a flowering plant prized for its rich, sweet scent. This small shrub is valued in gardens for its clusters of deep purple flowers and its distinctive fragrance, often described as a blend of vanilla and cherry pie. The name is derived from the Greek words helios (sun) and tropein (to turn), alluding to the plant’s slight tendency to face the sun (heliotropism). The word also describes a specific mineral and a color.
Defining the Botanical Heliotrope
The botanical heliotrope is the species Heliotropium arborescens, a tender perennial shrub native to the mountainous regions of Peru, Bolivia, and Colombia. It belongs to the Boraginaceae family and is often called the Cherry Pie plant. The plant features rough, oblong, dark green leaves with prominent veins growing on woody stems.
Its flowers bloom continuously from summer until the first hard frost in dense, flat-topped clusters. These small, five-petaled flowers are typically deep violet, blue-purple, or white, and produce the intense vanilla-like aroma. In cultivation, it typically reaches 1 to 1.5 feet, making it popular for containers and garden beds.
Cultivation and Growing Needs
Heliotrope thrives in locations that provide plenty of sunlight, ideally receiving at least six hours of direct sun each day. In extremely hot climates, the plant benefits from afternoon shade to prevent the foliage from scorching. The soil should be consistently moist, organically rich, and well-drained, as the plant will struggle in heavy clay or overly dry conditions.
Because it is tender, the plant is typically grown as a warm-weather annual outside of USDA Hardiness Zones 10 and 11. Gardeners should wait until all risk of frost has passed and the soil has warmed to at least 60°F before planting. To encourage a bushier growth habit and a greater number of flowers, the plant should be pinched back when young. Regular deadheading of spent flower clusters will promote continuous blooming.
Container-grown heliotropes require more frequent watering, sometimes daily during peak summer, to maintain soil moisture. Feeding the plant with a liquid fertilizer every two to four weeks supports abundant flower production. Using a fertilizer formulated for flowering plants with a high phosphorus content is recommended.
Safety Considerations
Despite its appealing scent, the heliotrope plant is toxic if ingested. All parts of the plant, including the leaves and flowers, contain pyrrolizidine alkaloids (PAs). These compounds are hepatotoxic, meaning they can cause serious damage to the liver.
Ingesting the plant can lead to gastric distress in humans and pets, potentially causing chronic liver failure if consumed over an extended period. The risk is significant for livestock, such as cattle and horses, where consumption can cause severe liver disease. The plant should be kept away from small children and household animals.
Other Meanings of Heliotrope
Beyond the fragrant flower, heliotrope is also an alternative name for the mineral Bloodstone. This stone is a type of chalcedony, a cryptocrystalline variety of quartz, characterized by its opaque, dark green body color. The mineral contains distinctive red, blood-like spots caused by inclusions of iron oxide, typically hematite.
The mineral’s name also comes from the ancient Greek phrase for “sun-turning,” referring to an old belief that placing the stone in water would turn the sun’s reflection red. In the context of color, heliotrope describes a specific shade of purplish-pink or reddish-purple. This hue closely resembles the deep color of the flower’s most common varieties and is used in fashion and art.