The heliotrope flower (Heliotropium) is a genus of flowering plants in the Boraginaceae family containing around 325 species. They are popular and stunning flowering perennials thanks to their aromatic and delicate old cottage-garden-style flowers. Heliotrope blooms are tiny flowers that grow in clusters that follow the sun, which led to their name which is directly derived from the Greek words helios (meaning ‘sun) and tropos (meaning ‘to turn’). Some gardeners describe the scent of the flowers as vanilla, while others insist they smell like cherry pie. Plant fast-growing heliotropes outdoors in the spring after the danger of frost has passed. This plant is toxic to humans and animals.
Heliotropes are temperate perennials that are native to the subtropical regions of Peru. When grown outside of their native range, heliotropes are usually grown as annuals as they are half-hardy and highly frost-tender.
Light
Heliotropes are full-sun plants that require at least six hours a day of direct sunlight. However, they prefer the morning sun, and in hot climates, intense afternoon rays may burn the delicate flowers. A location that receives bright morning sunlight and light shade in the afternoon is ideal.
Soil
Plant heliotropes in rich, loamy soil that is well-draining but retains some moisture. They prefer soil that is rich in organic matter, with a pH between 6.6 and 7.3. Heliotropes do not do well in heavy clay soils as they cannot tolerate wet feet.
Water
Heliotropes require lots of water to thrive. Keep the soil evenly moist, but not waterlogged, and don’t allow the plants to dry out. When grown in containers, heliotropes will need to be watered significantly more often as the plant will absorb the water more quickly.
Temperature and Humidity
Heliotropes grow best in climates with warm days and cool nights. They do not do well in overly hot or humid weather and they are highly frost-tender.
Fertilizer
Heliotropes are notoriously heavy feeders that need to be fertilized regularly throughout their growing season. When grown in the garden, heliotropes should be fertilized at least once a month. When grown in containers, they should be fertilized as often as every two weeks. Use a fertilizer high in phosphorus that is meant for flowering plants. For the amount to use, follow product label instructions.
Types of Heliotropes
There are many different varieties and cultivars of heliotropes. Here are a few popular heliotropes:
‘ Princess Marina’ (Heliotropium arborescens)
Clasping heliotrope (Heliotropium amplexicaule)
Beach heliotrope (Heliotropium anomalum)
Salt heliotrope (Heliotropium curassavicum)
Heliotropes can be propagated by cuttings or seeds. To propagate from stem cuttings in the spring or summer, follow these steps:
Take 4- to 5-inch stem cuttings from an outdoor heliotrope plant that’s fleshy and green.
Remove the leaves from the bottom half of the cutting and dip it in rooting hormone.
Put the cutting in a pot of moistened soil.
Place the pot on a sill with bright, indirect light. Avoid direct sunlight or the young plant can become scorched while trying to root.
Keep the cuttings moist.
After a few weeks the cuttings should root. Begin to bring the pots into brighter, more direct sunlight. Keep cuttings overwintered indoors.
Transplant outdoors or into a container garden in the spring.
How to Grow Heliotropes From Seed
Growing heliotropes from seed can be the easiest and most popular way to grow these flowering perennials. Seeds should be started indoors 10 to 12 weeks before the last frost to ensure that the plants have time to bloom before the first frost hits in the fall. Heliotrope seeds should be kept at a temperature between 70 to 75 degrees Fahrenheit and should germinate within 28 to 42 days. Once the last frost has passed, the heliotrope seedlings can be transplanted into the garden or a container outdoors.
Potting and Repotting Heliotropes
Heliotropes are perfect for pots because they are not aggressive and they won’t take over your container garden. They are also not prone to any serious pests or diseases. Keep in mind that heliotrope plants grown in containers will require significantly more water than plants grown in the garden.
Overwintering
Growing heliotropes in containers also means that they can be easily overwintered indoors if desired. Bring the plant indoors before the first frost. Place in a cool room on a sill with bright, indirect sunlight that will not scorch the plant. Water in small amounts to keep the plant from drying out. Do not place the plants near a heat source or risk dry soil. Bring back outdoors in the spring when temperatures rise consistently over 55 degrees Fahrenheit.
Common Pests and Plant Diseases
Watch for aphids, mealybugs, spider mites, fungus gnats, and whiteflies, which can all be treated with insecticidal soap or neem oil to resolve the infestation. Though the plant is not susceptible to many diseases, keep an eye out for fungal problems, such as powdery mildew, which occurs when air circulation is poor and soil conditions are very warm.
How to Get Heliotropes to Bloom
Regular pinching and deadheading of your outdoor heliotrope plant will encourage more consistent blooming and a bushier, denser growth habit. You can begin pinching back the stems and flowers in the early spring to encourage more lateral growth. This may delay the initial bloom but you will be rewarded with larger and more prolific blooms throughout the rest of the season. Indoor heliotrope may have a tougher time blooming, so make sure it’s moist enough, fertilized, and receives enough bright light.
