Smoke Tree

The smoke tree, also called smoke bush, is a shrub or small tree in the genus Cotinus. In early summer it is covered in fluffy, feathery plumes that look like puffs of pink, purple or gray smoke from a distance, which is how it got its name.

Scientific Classification & Quick Facts

Common name	Smoke tree
Scientific name	Cotinus
Kingdom	Plantae
Phylum	Tracheophyta
Class	Magnoliopsida
Order	Sapindales
Family	Anacardiaceae
Type	Deciduous small tree or large shrub
Habitat	Full sun, well-drained soil
Native range	Southern Europe, China and North America
Colours	Purple or green leaves turning red or orange in fall
Flowering season	Early summer
Height	10 to 15 feet
Special feature	Flower plumes look like puffs of smoke

A Relative of Sumac

Cotinus is a small genus in the cashew family, Anacardiaceae, which also includes sumacs, pistachios and mangoes. Smoke trees were once grouped with the sumacs in the genus Rhus, but they have simple, undivided leaves instead of the feather-like leaves of most sumacs.

There are two main species:

• European smoke tree (Cotinus coggygria), native from southern Europe across Asia to China. It usually grows about 10 to 15 feet (3 to 4.5 m) tall and wide.
• American smoketree (Cotinus obovatus), native to parts of the southeastern and central United States. It is larger, often 20 to 30 feet (6 to 9 m) tall, and has brilliant fall color.

What Makes the “Smoke”

The actual flowers of a smoke tree are tiny and yellowish, and not very showy. They grow in large, branching clusters 15 to 30 cm (6 to 12 inches) long. After the flowers fade, the thin stalks of the cluster grow long and covered in soft hairs. These hairy stalks form the cloudy, smoke-like plumes that last for weeks in summer.

Only a few of the flowers produce fruit, which is a tiny, dry drupe with a single seed.

Leaves and Fall Color

Smoke tree leaves are rounded or oval, about 3 to 13 cm (1 to 5 inches) long, and grow alternately along the stems. Depending on the variety, they can be green, deep purple or golden yellow. In autumn, they turn shades of yellow, orange, red or purple, and a dry, sunny summer often leads to even brighter fall colors.

Gardeners love smoke trees as eye-catching “specimen” plants, in mixed shrub borders, as informal screens or as a colorful accent near a patio or front lawn.

Growing a Smoke Tree at Home

Choosing a Site

Smoke trees grow best in full sun, which gives the strongest leaf color and the most plumes. They can handle light shade, but they will flower less. They are not fussy about soil and grow well in poor, rocky or even alkaline soils, as long as it drains well. Wet, heavy soil can cause root problems.

Most smoke trees grow well in USDA zones 5 to 8, and some are hardy in zone 4.

Planting

Photo by: Andrzej Otrębski

• Dig a hole about twice as wide as the root ball and about as deep.
• Mix a shovelful or two of compost into the soil you removed.
• Set the plant so the top of the root ball is level with, or slightly above, the surrounding ground.
• Fill the hole halfway, firm the soil gently and water to settle it, then finish filling.
• Build a low ring of soil about 3 inches high around the root ball to hold water.
• Spread 2 to 3 inches of mulch around the plant, keeping it a few inches away from the trunk.

Watering

Water deeply right after planting. During the first growing season, water about once a week, more often in very hot weather. To check if a plant needs water, squeeze a handful of soil near the root ball: if it drips, it is too wet, and if it crumbles and feels dry, it is time to water. Once established, smoke trees are quite drought tolerant and need watering only during long dry spells.

Pruning

Smoke trees need little pruning. If you want the most “smoke,” just remove dead, damaged or crossing branches in late winter or early spring, because plumes form on older wood.

Some gardeners cut their smoke bushes back hard in early spring. This produces long new shoots with extra-large, colorful leaves, but it means few or no plumes that year. It is a good choice if you grow a purple or golden variety mainly for its foliage.

Pests and Diseases

Smoke trees have few problems. The most serious is Verticillium wilt, a soil fungus that causes branches to wilt and die. There is no cure, but cutting out affected branches and keeping the plant healthy can help. Powdery mildew sometimes appears on the leaves in humid weather, but it is usually harmless.

Popular Varieties

• ‘Royal Purple’: deep red-purple leaves that turn scarlet in fall, with purplish-pink plumes. Grows about 10 to 15 feet tall.
• ‘Golden Spirit’ (also sold as ‘Ancot’): bright golden leaves in spring that soften to lime green in summer, then turn orange and red in fall. Usually about 6 to 10 feet tall.
• ‘Grace’: a hybrid of the European and American species with wine-purple leaves, very large pink plumes and orange-red fall color. Can reach about 15 feet or more.
• ‘Nordine’: purple-bronze leaves that turn red and orange in fall; known for being especially cold-hardy.
• ‘Notcutt’s Variety’: dark wine-red leaves that turn red-orange in fall, with pinkish plumes.
• ‘Pink Champagne’: green leaves and pale pink plumes, with orange and red fall color.
• ‘Velvet Cloak’: very dark purple-red leaves that turn bright red in autumn.

Smoke tree FAQs

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