Royal Purple smokebush

Sun

Full sun gives the richest purple foliage and best flowering. Tolerates light partial shade, but leaves may become greener.

Water

Water regularly while establishing. Once established, it tolerates dry spells; water deeply during prolonged drought rather than watering lightly every day.

Soil

Well-drained soil, including chalky, stony or moderately poor ground. Tolerates acid to alkaline conditions but dislikes waterlogged soil.

Height

10-15 ft (3-4.6 m)

Spread

10-15 ft (3-4.6 m)

Flowers

Small yellow-green flowers in late spring to early summer, followed by hazy pinkish-purple plumes of feathery flower stalks through summer.

Foliage

Rounded to oval, deep burgundy-purple leaves, often with brighter edges in sunlight. Autumn colour can include scarlet, orange and red-purple, varying with weather and site.

Growth

Moderate; vigorous new shoots follow hard pruning.

Care needed

Low

• Pollinators
• Deer resistant
• Drought tolerant
• Wildlife

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

Difficulty

Easy

Toughness

Very tough

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

1. Planting day

   1.6 ft (0.5 m)

2. After 1 year

   4 ft (1.3 m)

3. After 2 years

   7 ft (2.2 m)

4. After 3 years

   10 ft (3 m)

5. After 5 years

   12 ft (3.8 m)

   full size

About 4 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

Safe

Growth rate

Fast

• Water deeply during dry weather for the first two growing seasons, allowing the soil surface to dry between waterings.
• Apply 2-3 in (5-8 cm) of organic mulch over the root area, keeping it clear of the stems.
• Avoid routine heavy feeding; on poor soil, add a thin layer of compost in spring.
• Plant where water drains freely, and avoid low spots that stay wet in winter.
• Allow space for its mature width rather than repeatedly clipping it to fit a narrow bed.

Pruning. In late winter or early spring, remove dead, damaged or crossing branches and otherwise prune lightly to retain flowers. For larger leaves on a smaller plant, cut established stems back to a low framework at this time, accepting that this usually sacrifices that year's smoke display.

Late winter

Remove dead or crossing branches; carry out hard pruning only if foliage is more important than flowers.

Spring

Plant into workable, well-drained soil and water thoroughly.

Mid-spring

Renew mulch, leaving a clear gap around the stems.

Summer

Water young plants during dry spells and check any sudden wilting for drainage or root problems.

Midsummer

Take semi-ripe cuttings if you want to attempt propagation of the cultivar.

Autumn

Plant in mild regions while the soil is still warm; in cold regions, spring planting is safer.

• Use as a specimen in an open lawn or broad bed, where its rounded outline and summer plumes can be seen clearly.
• Place behind silver-leaved plants and ornamental grasses for a strong foliage contrast.
• Combine with lime-green foliage or yellow flowers to brighten a sunny mixed border.
• Use as a dark backdrop to late-flowering perennials, allowing enough space for its mature spread.

Garden styles it suits: Architectural minimal, Modern, English country, New perennial (prairie), Dry gravel garden and Autumn colour.

Plant it with: Russian sage, Catmint, Feather reed grass, Yarrow, Lamb's ears and Coneflower.

Wildlife: The small flowers attract some visiting insects, and a mature shrub provides shelter for birds. The smoky plumes are mainly feathery stalks, not masses of nectar-rich flowers.

• Verticillium wilt can cause sudden wilting and branch dieback. Prune out dead growth, avoid drought stress and seek a diagnosis; there is no reliable chemical cure, and badly affected plants may need removal.
• Waterlogged soil can cause root decline and dieback. Improve drainage or move the plant to a freely draining site rather than simply reducing summer watering.
• Powdery mildew may coat leaves in dry, crowded conditions. Improve airflow, water the root zone during drought and remove fallen affected leaves.
• Poor purple colour or few plumes usually follows too much shade or hard pruning. Give it more sun and retain older stems if you want flowers.

Not known to be toxic to cats, dogs or horses. It is not generally regarded as poisonous to people, but sap from cut stems can irritate sensitive skin; wear gloves when pruning. No part is intended as food.

• Forest Pansy eastern redbud (Cercis canadensis 'Forest Pansy')

  Also has purple foliage, but its leaves are distinctly heart-shaped with pointed tips. It bears pink pea-like flowers on bare branches rather than smoky summer plumes.

• Purpleleaf sand cherry (Prunus × cistena)

  Has narrower, toothed purple leaves and small pinkish-white spring flowers. Smokebush leaves have smooth margins and are more rounded.

• American smoketree (Cotinus obovatus)

  Usually develops into a larger tree with larger green leaves and vivid autumn colour. It lacks the persistent deep-purple summer foliage of 'Royal Purple'.

The name smokebush refers to the hazy, smoke-like clusters of feathery flower stalks that remain after flowering.

Propagation. Layer a low branch, or try softwood to semi-ripe cuttings in late spring or summer with rooting hormone and a humid propagator; rooting can be difficult. Seedlings do not reliably retain the characteristics of 'Royal Purple'.

Accepted botanical name

Cotinus coggygria

In the US and Canada

Introduced in Canada and the lower 48 states.

Native range

Albania, Austria, Bulgaria, China North-Central, China South-Central, China Southeast, Czechoslovakia, East Himalaya, France, Greece, Hungary and Iran.

Measured

Soil pH 7 to 7.5. Average height 260 cm.

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