Heliotrope

Sun

Full sun in cool climates; afternoon shade in hot climates.

Water

Keep evenly moist but not waterlogged. Container plants may need daily watering in hot weather.

Soil

Fertile, moisture-retentive soil with good drainage; use a free-draining potting mix in containers.

Height

1-3 ft (0.3-0.9 m) in seasonal plantings; up to 6 ft (1.8 m) as a mature frost-free shrub

Spread

1-3 ft (0.3-0.9 m)

Flowers

Late spring to autumn, usually until frost; violet-purple, lavender or white flowers in dense, rounded clusters.

Foliage

Evergreen. Dark green, oval leaves with prominent veins and a wrinkled, slightly hairy surface.

Growth

Moderate

Care needed

Medium

• Pollinators
• Low allergen
• Fragrant

Northern hemisphere months. In Australia, shift them by six.

Difficulty

Moderate

Toughness

Needs looking after

Pick your zone, country, light and whether you have pets.

1. Planting day

   1.6 ft (0.5 m)

2. After 1 year

   1.7 ft (0.52 m)

3. After 2 years

   1.8 ft (0.54 m)

4. After 3 years

   1.8 ft (0.56 m)

5. After 5 years

   2 ft (0.6 m)

   full size

About 5 years to full size.

From a typical nursery size, at an average rate for this kind of plant. A rule of thumb, not a forecast.

Cats and dogs

Toxic

Growth rate

Moderate

• Plant outside only after frost risk has passed and nights are reliably mild.
• Water at soil level when the surface begins to dry; avoid letting the root ball dry out completely.
• Feed container plants every two to four weeks during active growth with a balanced liquid fertiliser at the label rate.
• Apply a light organic mulch around border plants, keeping it clear of the stems.
• Move plants you want to keep into a bright, frost-free place before cold weather; water less in winter without allowing complete drying.

Pruning. Pinch young shoot tips in spring to encourage branching, and remove faded flower clusters throughout summer. Lightly shorten overwintered plants in early spring, cutting back to healthy leafy growth.

Late winter

Sow seed indoors with warmth and light, or check overwintered plants for whitefly and aphids.

Spring

Pinch young plants and gradually acclimatise indoor-grown plants to outdoor conditions.

Late spring

Plant out after the last frost, allowing room for air circulation and mature spread.

Summer

Water regularly, feed container plants and remove spent flower clusters.

Late summer

Take non-flowering softwood or semi-ripe cuttings if you want to keep a particular plant.

Autumn

Bring retained plants under frost-free cover before cold nights; remove frost-killed bedding plants.

• Place containers near seating areas where the flower scent can be appreciated, but away from pets that chew plants.
• Use compact forms along the front of summer borders with silver foliage and white flowers.
• Repeat purple-flowered plants through cottage borders to link pink, blue and cream planting.
• Grow as seasonal bedding within low clipped hedges for a traditional formal display.

Garden styles it suits: Cottage garden, Traditional, Victorian, Sensory garden, Modern courtyard and Pollinator garden.

Plant it with: Petunias, Sweet alyssum, Salvias, Dusty miller, Pelargoniums and Cosmos.

Wildlife: Flowers attract butterflies and other nectar-feeding insects. Avoid spraying open flowers or visiting pollinators.

• Whitefly and aphids: inspect shoot tips and leaf undersides, especially under cover; use insecticidal soap labelled for the pest and plant if needed.
• Spider mites in hot, dry conditions: look for fine webbing and speckled leaves; rinse leaf undersides and prevent drought stress.
• Root rot in wet soil: improve drainage, empty standing water from saucers and avoid watering an already wet root ball.
• Brown leaf edges, wilting or poor flowering: prevent repeated drying, provide afternoon shade in strong heat and ensure adequate light in cool climates.

All parts should be treated as toxic to people, cats, dogs and horses if eaten. Heliotrope contains pyrrolizidine alkaloids that can cause serious liver damage, particularly with repeated ingestion; do not use the flowers or leaves as food. Seek medical or veterinary advice after ingestion.

• Lantana (Lantana camara)

  Lantana has rough, toothed leaves and often multicoloured flower heads that change colour with age. Heliotrope usually has more uniformly coloured flower clusters and a sweet floral scent.

• Floss flower (Ageratum houstonianum)

  Floss flower has fuzzy, threadlike flower heads rather than heliotrope's tiny flowers with visible five-lobed faces.

Heliotropium comes from Greek words meaning sun and turning, referring to an old belief that these plants turned towards the sun, while arborescens means becoming tree-like.

Propagation. Sow seed indoors in late winter or early spring, pressing it onto the surface and keeping it warm and moist; germination can be slow and uneven. Take non-flowering softwood or semi-ripe cuttings in summer to preserve a cultivar's characteristics.

Accepted botanical name

Heliotropium arborescens

In the US and Canada

Introduced in the lower 48 states and Puerto Rico.

Native range

Bolivia, Colombia and Peru.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.