Heliotrope

Heliotrope: how do you recognise it?

Habit

Compact, bushy plant about 45 cm high and 40 cm wide; in its homeland a perennial shrub.

Leaves

Dark green, oval, 5–8 cm, with a deeply wrinkled surface.

Flower

Very small flowers in dense, curled clusters forming heads of 10–15 cm, from June to September.

Colour

Violet to lavender-blue, sometimes white; the cultivar ‘Marine’ is deep violet-blue.

Scent

Strong vanilla scent, strongest in warmth.

Flowering: June–September · Sowing: February–March · Plants: May–June · Pruning: March and May

Why grow it?

• The flowers smell strongly of vanilla, especially on warm days: ideal beside the patio or a seating area.
• Flowers from June to September in dense, violet clusters.
• Bees and butterflies love the flowers.
• Lovely in containers, pots and borders; can also be grown as a standard.
• Can be overwintered indoors as cuttings or as a whole plant.

Heliotrope: where does it grow best?

• Full sun and a warm, sheltered spot; in too much shade it becomes thin and flowers less.
• Rich, humus-rich, well-drained soil: sandy, loamy or clay, acid to chalky. In containers use good-quality potting compost.
• Evenly moist: the soil must not dry out, but must not stay waterlogged either.
• Allow 30–40 cm between plants; put it near the patio so you can enjoy the scent.

Light

Sun

Soil type

Sand, loam or clay

Acidity

Not fussy

Moisture

Normal

Size

0.45 m tall, 0.4 m wide

Hardiness

Frost tender: plant out after the last frost (mid-May)

Goes well with

• Petunia: White or pink petunias fill the container and make the violet stand out.
• Verbena: Flowers just as long in sun and gives colour contrast.
• Pelargonium: Red or white flowers beside the scented violet.
• Salvia: Blue flower spikes that harmonise well with the violet clusters.
• Dahlia: Warm-coloured flowers in the border, with heliotrope as scented underplanting.

Heliotrope: when and how to plant it?

Plant in May–June.

1. Sow indoors in February–March at about 20 °C; the seed germinates slowly, in 2–4 weeks. Cover it only lightly. You can also buy young plants.
2. Prick the seedlings out into small pots and grow them on in a bright, cool place.
3. Plant out in May–June, when frost is no longer expected; it is sensitive to cold and needs at least 2 °C.
4. Dig a hole as deep as the rootball and mix in a little compost. In containers: potting compost, with drainage holes.
5. Space plants 30–40 cm apart and water well straight away.
6. Pinch the young plant after planting to encourage bushy growth.

Care

Water

Regular, so that the soil stays evenly moist. In dry spells the leaves droop quickly; in containers water daily in hot weather.

Feeding

Every two weeks, liquid feed for flowering plants in containers; in the border add compost at planting.

Spent flowers

Cut faded clusters back to above a new leaf: the plant keeps flowering and stays compact.

Pinching

Pinch out the tips of young shoots in May: the plant becomes bushier and flowers more.

Support

A stake is useful for standard heliotropes and for large plants in wind.

Repotting

Repot overwintered plants in March into fresh compost and a slightly larger pot.

Tip: Put it right beside the patio or seating area and water regularly: the vanilla scent is strongest on warm days. Do not plant out before mid-May.

Heliotrope: when to prune it?

Pruning months: March and May.

When: Pinch in May and cut back an overwintered plant in March; during flowering, remove faded clusters.

How:

• Cut overwintered plants back by about a third in March, just above a healthy bud.
• Pinch out the tips of young shoots in May for bushy growth.
• During summer, cut faded flower clusters back to above a new leaf.
• Remove dead, weak or bare stems completely.

Pruning: when and how · Pruning calendar and basic rules

Propagation

Seed

Sow indoors in February–March at about 20 °C. The seed germinates slowly; grow the plants on and set them outside in May.

Cuttings

In August–September: take 8–10 cm tip cuttings from non-flowering shoots, remove the lower leaves and insert in moist cuttings compost at 18–20 °C. They root within a few weeks.

Heliotrope: how does it get through the winter?

Hardy to 2 °C: protect in harsh winters.

• Not hardy: it tolerates no frost and is grown outdoors as an annual.
• Bring it indoors before the first frost, in October: cut it back by a third and keep it bright and cool at 10–15 °C with little water.
• You can also take cuttings in late summer and overwinter them indoors, giving you new plants for next year at little cost.

Diseases and pests

• Whitefly and aphids: Small white flies and aphids under the leaves and on young shoots. Wash off with water, use yellow sticky traps or release ladybirds.
• Red spider mite: Mostly during overwintering in warm, dry air: fine webs and yellowing leaves. Mist the plant regularly and move it to a cooler place.
• Powdery mildew and grey mould: White powder or grey fuzz in damp weather. Allow space, remove affected parts and water at the base.
• Drooping leaves: A sign of drought or root rot from too much water. Check the soil and adjust your watering.

Through the year

• February: Sow indoors at about 20 °C.
• March: Sow. Cut back and repot overwintered plants.
• April: Prick out seedlings and grow them on in a bright, cool place.
• May: Pinch back. Plant out after the ice saints.
• June: Flowering begins. Water regularly and feed.
• July: Full flower. Remove faded clusters.
• August: Flowering. Take cuttings.
• September: Last flowers. Root the cuttings.
• October: Bring indoors before the first frost.

Edible and useful

Not edible. These plants contain pyrrolizidine alkaloids, like the common ragwort along the roadsides: they damage the liver, even in small amounts taken in over a long time, and the damage is permanent. Horses and cattle are the most sensitive, also to dried plants in hay or silage, because they can no longer taste them: do not plant them in or beside a field, never throw mowings or trimmings near the feed, and do not cut them with grass for hay. Never make teas or herbal remedies from them, not even from hemp agrimony, which was once a medicinal herb. Keep children, dogs and cats away from the plant and wear gloves when cutting back. If any is swallowed, call a poison centre (in Belgium 070 245 245) or your doctor at once.

Good for wildlife

Bees

Nectar and pollen for honeybees and wild bees.

Butterflies

Nectar for butterflies.

Did you know?

• The name Heliotropium comes from Greek: helios means sun and tropos turning, because people once believed the flowers followed the sun.
• In Victorian times heliotrope was a popular scented plant in conservatories and gardens.
• In a warm climate without frost it grows as a perennial shrub that becomes much taller than the plants in our containers.