Spider flower

Sun

Full sun gives the strongest stems and best flowering; light shade is tolerated.

Water

Water regularly while establishing, then during prolonged dry spells. Established plants tolerate some drought but flower better with moderate moisture.

Soil

Well-drained soil of average fertility. Avoid waterlogged ground and heavy feeding.

Height

3-5 ft (0.9-1.5 m); compact cultivars are shorter

Spread

1-2 ft (0.3-0.6 m)

Flowers

Summer to autumn, until frost; pink, rose-purple or white, sometimes fading to a paler shade as flowers age.

Foliage

Green, palmately divided leaves, usually with five to seven narrow leaflets. Leaves and stems can be sticky and strongly scented when handled; many forms have small prickles.

Growth

Fast; reaches flowering size in one growing season.

Care needed

Low

• Plant out after frost danger has passed and the soil has warmed, spacing plants 1-2 ft (0.3-0.6 m) apart.
• Water at soil level when the surface begins to dry; do not leave the roots in saturated soil.
• Work a little compost into poor soil before planting; avoid repeated high-nitrogen feeding.
• Apply a light mulch after the soil warms, keeping it clear of the stems.
• Support tall plants in exposed gardens before wind loosens their roots.
• Remove developing seed pods if you do not want volunteer seedlings.

Pruning. Pinch out the growing tip of young plants if you want bushier growth, accepting slightly later flowering. During summer, remove spent flower clusters and seed pods as needed; pull up plants after frost kills them.

Early spring

Sow seed indoors in a warm, bright place; germination can be uneven, so allow several weeks.

Spring

Pot on seedlings and gradually acclimatise them to outdoor conditions.

Late spring

Plant out after the last frost, or sow directly once the soil is warm.

Early summer

Mulch, water young plants during dry weather and support tall plants in windy positions.

Summer

Remove unwanted seed pods and check shoot tips for aphids.

Autumn

Collect ripe seed from non-hybrid plants if wanted, then remove plants once frost or seasonal decline ends flowering.

• Plant in loose groups through the middle or back of a sunny border for height and see-through flower colour.
• Combine with cosmos, zinnias and salvias for a long-flowering summer display.
• Use white-flowered forms beside a terrace for flowers that remain conspicuous at dusk.
• Grow compact forms in large containers with drainage holes.
• Keep prickly forms back from narrow paths and seating edges.

Garden styles it suits: Cottage garden, English country, Pollinator garden, White garden, Romantic rose garden and Evening garden.

Plant it with: Cosmos, Zinnia, Verbena bonariensis, Salvia, Purple coneflower and Ornamental grasses.

Wildlife: Flowers attract bees, butterflies and moths; hummingbirds may visit in North America. It is a South American plant, not a native substitute for local host plants.

• Aphids can cluster on soft shoot tips; wash them off with water and preserve ladybirds and other predators.
• Spider mites may cause pale stippling in hot, dry conditions; avoid drought stress and rinse leaf undersides, using insecticidal soap if needed.
• Poor flowering and floppy growth often follow excessive shade or nitrogen feeding; move future plantings into full sun and reduce fertiliser.
• Root rot can develop in waterlogged soil; improve drainage and allow the soil surface to dry between waterings.

Not known to be toxic to cats, dogs or horses, and not generally regarded as poisonous to people. It is not an edible garden plant. Prickles can scratch skin, and sticky foliage may irritate sensitive skin; wear gloves when handling.

Where it spreads. Readily self-seeds and can become weedy. It has naturalised and is regarded as an environmental weed in parts of Queensland and New South Wales, Australia. Check local guidance before planting there and remove seed pods to limit escape.

• African spider flower (Gynandropsis gynandra)

  Usually has smaller white flowers in looser clusters and generally lacks the conspicuous paired prickles found on many garden spider flowers.

• Clammyweed (Polanisia dodecandra)

  Usually much shorter, with three leaflets per leaf and smaller white flowers with projecting stamens.

• Spider plant (Chlorophytum comosum)

  The familiar houseplant has arching, strap-shaped leaves and plantlets on trailing stems, not tall leafy stems with large flower clusters.

The common name refers to the long, leg-like stamens projecting from each flower, while hassleriana honours the botanist Émile Hassler.

Propagation. Grow from seed, either indoors before the last frost or directly outdoors after the soil warms. Cover lightly and keep evenly moist; germination can be irregular. Seed saved from hybrids may not resemble the parent, and some cultivars are sterile.

Accepted botanical name

Tarenaya houtteana Cleome hassleriana is an older name for Tarenaya houtteana.

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