In summer, feathery filaments of panicles rise above the blue-green foliage on smoke bush (Cotinus coggygria), creating the “smoky” appearance that gives this shrub its common name. Fall brings more drama, as leaves turn various colors of purple, red, orange and yellow. Dark-foliage cultivars such as ‘Royal Purple’ unfurl lovely wine-purple foliage early in the season and turn scarlet-red in fall. Smoke bush has a loose, multistemmed habit, but vigorous pruning keeps it neater. Sometimes large, older shrubs are pruned up to become small trees.
Common name: Smoke bush, smoke tree, Venetian sumac
Botanical name: Cotinus coggygria
Plant type: Deciduous shrub or small tree
Zones: 5 to 8
Height: 10 to 15 feet tall
• Sun: Full sun
• Soil: Tolerates a wide range of soil, including dry, rocky sites and poor soil. Must be well drained.
• Moisture: Medium to dry
• Mulch: Use 1 to 3 inches of mulch around the base of the shrub, leaving a couple of inches between stems and mulch.
• Pruning: In late winter, prune out crossing, broken, or dead stems.
• Fertilizer: None needed.
• Root softwood cuttings in summer.
Pests and diseases
• Verticillium wilt occurs occasionally.
• Powdery mildew may attack purple cultivars.
• Smoke bush is attractive as a specimen plant.
• It provides good screening when planted as a hedge.
• Plant in full sun for best leaf color on purple cultivars—except in southern climates where purple color may fade in long, hot summers.
• Purple foliage contrasts beautifully with green foliage in floral arrangements and in the landscape.
• Cut purple-leafed selections to the ground in winter for a more uniform plant that is full and dense.
• Smoke bush will grow in damp sites, but does better in drier spots.
• ‘Royal Purple’ has pinkish-purple seed clusters. Foliage starts maroon red in spring, matures to dark purple, then turns vivid scarlet in fall. Grows 10 to 15 feet tall. Zones 5 to 8.
• ‘Flame’ has light green leaves that turn orange-red in fall. Grows 20 feet tall. Zones 5 to 8.
• ‘Pink Champagne’ has foliage that starts bronzy purple and turns green. Grows 6 to 10 feet tall. Zones 5 to 8.
• ‘Velvet Cloak’ has purple foliage in summer and red-purple in fall. Very similar to ‘Royal Purple’. Grows 10 to 15 feet tall. Zones 5 to 8.
All in the family
• Though most members of the cashew family live in the tropics, a few are native to temperate zones. They include smooth sumac (Rhus glabra), staghorn sumac (R. typhina), fragrant sumac (R. aromatica), and Chinese pistache (Pistacia chinensis).
Where to buy
• The Arbor Day Foundation, Nebraska City, NE, 888-448-7337, www.arborday.org
• Forestfarm, Williams, OR, 541-846-7269, www.forestfarm.com
(Text by Mary Pestel, photo of Cotinus coggygria courtesy of Kemper Center for Home Gardening at the Missouri Botanical Garden)