Light
Heliotropes are full sun plants that require at least six hours a day of direct sunlight. However, they prefer 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.
Water
Heliotropes require lots of water in order 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.
Soil
Plant heliotropes in rich, loamy soil that is well-draining but retains some water. 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.’
Temperature and Humidity
Heliotropes grow best in dry climates with warm days and cool nights. They do not do well in overly hot or humid weather and they are highly frost-tender. They grow well in USDA zones 9 through 11.
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.
Types of Heliotrope
There are many different varieties of heliotropes, but the most popular heliotrope varieties are as follows:
Heliotropium arborescensHeliotropium amplexicaule Heliotropium anomalumHeliotropium curassavicumHeliotropium indicum
Growing Heliotropes in Containers
Heliotropes make great container plants as they are small plants, that are not invasive (i.e. they won’t take over your container garden!) and they are not prone to any serious pests or diseases. Growing heliotropes in containers also means that they can be easily overwintered indoors if desired. Keep in mind that heliotrope plants grown in containers will require significantly more water than plants grown in the garden.
Pruning
Regularly pruning your heliotrope plant will encourage consistent blooms and a fuller 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.
How to Grow Heliotropes From Seed
Growing heliotropes from seed is the easiest and most popular way to grow these flowering perennials. Seeds should be started indoors 10-12 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 70-75 degrees Fahrenheit (12-24 degrees Celsius) and should germinate within 28-42 days. Once the last frost has passed, the heliotrope seedlings can be transplanted into the garden or a container outdoors.
