Heliotrope (Heliotropium arborescens) is a perennial plant that belongs to the borage family. It is native to South America, where it grows in sunny and dry conditions. Heliotrope has clusters of small flowers that range from white to purple in color and have a sweet vanilla or cherry pie fragrance. The flowers are also attractive to bees, butterflies, and hummingbirds.
Heliotrope is commonly grown outdoors as a bedding plant or a container plant, but it can also be grown indoors as a houseplant with some extra care. Heliotrope can add a touch of color and scent to your indoor space, especially during the winter months when it blooms.
However, heliotrope is not a pet-friendly plant. All parts of the plant are toxic to animals and can cause vomiting, diarrhea, and other symptoms if ingested. 1 Therefore, you should keep this plant away from your furry friends and children.
Here are some tips on how to grow and care for heliotrope indoors.
Light
Heliotrope needs plenty of bright light to produce flowers. It prefers at least six hours of direct sunlight per day, preferably in the morning. A south- or west-facing window is ideal for heliotrope. If you don’t have enough natural light, you can supplement it with a grow light.
Soil
Heliotrope likes a rich, loamy, and well-draining potting mix. You can use a standard houseplant potting mix or make your own by combining one part peat moss or coco coir, one part perlite, and one part compost. Heliotrope prefers a neutral to slightly alkaline soil pH, between 6.6 and 7.3.
Water
Heliotrope likes to be kept moist but not soggy. Water your plant whenever the top inch of the soil feels dry to the touch. Avoid letting the soil dry out completely or become waterlogged, as both can cause stress and damage to the plant. Reduce watering slightly in the winter when the plant is not actively growing.
Temperature and Humidity
Heliotrope thrives in warm and dry conditions. It can tolerate temperatures between 60°F and 80°F (16°C and 27°C), but it does not like extreme heat or cold. Keep your plant away from drafts, heaters, air conditioners, and windows that may expose it to temperature fluctuations. Heliotrope does not need high humidity, but it may benefit from occasional misting or placing it on a tray of pebbles and water.
Fertilizer
Heliotrope is a heavy feeder that needs regular fertilization during the growing season. Use a balanced liquid fertilizer every two weeks from spring to fall, or a slow-release granular fertilizer at the beginning of the season. Choose a fertilizer that is high in phosphorus (the middle number on the label) to encourage blooming.
Pruning
Heliotrope does not need much pruning, except for removing dead or damaged leaves and flowers. You can also pinch back the tips of the stems to promote bushier growth and more flowers. If your plant becomes leggy or overgrown, you can cut it back by one-third in late winter or early spring before new growth starts.
Propagating
You can propagate heliotrope by seeds or cuttings. Seeds can be sown indoors in late winter or early spring, about six to eight weeks before the last frost date. Sow them on the surface of moist potting mix and cover them lightly with vermiculite or perlite. Keep them in a warm (70°F to 75°F or 21°C to 24°C) and bright location until they germinate.
Cuttings can be taken from an established plant in spring or summer. Cut a 4- to 5-inch stem tip just below a leaf node and remove the lower leaves. Dip the cut end in rooting hormone and insert it into moist potting mix. Keep it in a warm and bright location until roots form.
Growing From Seeds
If you want to grow heliotrope from seeds, you will need to start them indoors about six to eight weeks before the last frost date in your area. You will need:
- A seed tray or small pots
- A sterile potting mix
- Heliotrope seeds
- Vermiculite or perlite
- A plastic dome
To grow heliotrope from seeds, follow these steps:
- Fill the seed tray or pots with moist potting mix and press it lightly to make it firm.
- Sprinkle the heliotrope seeds evenly over the surface of the potting mix. Do not cover them too deeply, as they need light to germinate. A thin layer of vermiculite or perlite can help retain moisture and prevent fungal growth.
- Cover the seed tray or pots with a plastic dome or a clear plastic bag to create a mini greenhouse. This will help maintain humidity and warmth for the seeds.
- Place the seed tray or pots in a warm (70°F to 75°F or 21°C to 24°C) and bright location, but not in direct sunlight. A windowsill or a heated propagator can work well.
- Check the potting mix daily and mist it lightly if it feels dry. Do not overwater or let the potting mix become soggy, as this can cause the seeds to rot.
- Watch for signs of germination, which can take anywhere from 10 to 30 days. Once the seeds sprout, remove the plastic dome or bag and move the seed tray or pots to a brighter location with indirect sunlight.
- Thin out the seedlings by removing the weakest ones and leaving only one per cell or pot. You can transplant them to larger pots when they have two sets of true leaves.
- Harden off the seedlings gradually before moving them outdoors after the last frost date. Choose a sunny spot with well-draining soil and space them about 12 inches apart.
Common Pests and Diseases
Heliotrope is generally pest- and disease-resistant, but it can occasionally suffer from some problems. Some common pests that may attack heliotrope are:
- Aphids: These are small, soft-bodied insects that suck the sap from the leaves and stems. They can cause yellowing, curling, and distortion of the foliage. They can also spread viral diseases. You can control aphids by spraying them with insecticidal soap or neem oil, or by releasing beneficial insects such as ladybugs or lacewings that feed on them.
- Spider mites: These are tiny arachnids that also suck the sap from the leaves and stems. They can cause fine webbing, speckling, and browning of the foliage. They thrive in hot and dry conditions. You can control spider mites by increasing humidity around the plant, spraying them with water or miticides, or by releasing predatory mites that feed on them.
- Whiteflies: These are small, white-winged insects that also suck the sap from the leaves and stems. They can cause yellowing, wilting, and dropping of the foliage. They can also excrete honeydew, which attracts ants and fungal growth. You can control whiteflies by spraying them with insecticidal soap or neem oil, or by using sticky traps or vacuuming them off.
Some common diseases that may affect heliotrope are:
- Powdery mildew: This is a fungal disease that causes white, powdery patches on the leaves and stems. It can reduce photosynthesis and weaken the plant. It is more likely to occur in humid and crowded conditions. You can prevent powdery mildew by providing good air circulation around the plant, avoiding overhead watering, and removing any infected parts. You can also treat powdery mildew with fungicides or baking soda spray.
- Root rot: This is a fungal disease that causes decay and rotting of the roots and lower stems. It can cause wilting, yellowing, and death of the plant. It is more likely to occur in wet and poorly drained soil. You can prevent root rot by using well-draining potting mix, watering moderately, and avoiding over-fertilizing. You can also treat root rot with fungicides or hydrogen peroxide solution.
Bloom
Heliotrope blooms from summer to fall, producing clusters of fragrant flowers that range from white to purple in color. The flowers are attractive to bees, butterflies, and hummingbirds.
To encourage more blooms, you should deadhead spent flowers regularly. This will prevent seed formation and stimulate new flower buds.
You should also fertilize your plant regularly during the blooming season with a high-phosphorus fertilizer.
Common Issues
Some common issues that may affect heliotrope are:
- Legginess: This is when the plant grows tall and spindly with few leaves and flowers. It is usually caused by insufficient light or too much fertilizer. You can prevent legginess by providing adequate light for your plant and fertilizing moderately. You can also prune back leggy stems in late winter or early spring to promote bushier growth and more flowers.
- Leaf drop: This is when the plant loses its leaves prematurely. It is usually caused by stress from overwatering, underwatering, temperature fluctuations, or pests and diseases. You can prevent leaf drop by providing consistent and appropriate care for your plant and treating any pest or disease problems promptly.
- Flower drop: This is when the plant drops its flowers before they open or soon after they open. It is usually caused by stress from overwatering, underwatering, temperature fluctuations, or low humidity. You can prevent flower drop by providing consistent and appropriate care for your plant and increasing humidity around it.
Frequently Asked Questions
- Is heliotrope an annual or a perennial? Heliotrope is a perennial plant that can grow outdoors year-round in USDA zones 9 to 11. However, it is often grown as an annual in colder climates, as it cannot tolerate frost.
- How do you overwinter heliotrope? If you want to overwinter heliotrope indoors, you should bring it inside before the first frost and place it in a bright and cool location. You should reduce watering and fertilizing and prune back any leggy or damaged stems. You should also inspect the plant for any pests or diseases and treat them accordingly. You can move the plant back outdoors in spring after the last frost.
- Why does my heliotrope smell like cherry pie? Heliotrope has a sweet and pleasant fragrance that resembles vanilla or cherry pie. This is due to the presence of a chemical compound called heliotropin in the flowers, which is also used as a flavoring agent and a perfume ingredient.
