Smoketree (Cotinus coggygria)

Common Smoketree, Smokebush, Smoketree

Add colorful foliage to your landscape from spring to fall with the perennial smoke tree. Grown as a large shrub or small tree, the plant offers oval leaves in shades of rich purple, gold, or green throughout the gardening season. Hardy in Zones 5-8, when the weather cools in autumn, they turn shades of yellow, orange, and red. Smoke tree gets its common name from its fluffy buff-pink summertime bloom clusters. It’s a reliable performer in the garden, holding up well in hot, dry conditions once the plant is established.

I. Appearance and Characteristics 

Cotinus coggygria, syn. Rhus cotinus, the European smoketree, Eurasian smoketree, smoke tree, smoke bush, Venetian sumach, or dyer’s sumach, is a Eurasian species of flowering plant in the family Anacardiaceae. The species is native to a large area from southern Europe, east across central Asia and the Himalayas to northern China.

It is a multiple-branching deciduous shrub growing to 5–7 meters (16–23 feet) tall with an open, spreading, irregular habit, only rarely forming a small tree. The leaves are 3–8 centimeters (1+1⁄4–3+1⁄4 inches) long rounded ovals, green with a waxy glaucous sheen. The autumn color can be strikingly varied, from peach and yellow to scarlet. The flowers are numerous, produced in large inflorescences 15–30 cm (6–12 in) long; each flower 5–10 millimeters (1⁄4–3⁄8 in) in diameter, with five pale yellow petals. Most of the flowers in each inflorescence abort, elongating into yellowish-pink to pinkish-purple feathery plumes (when viewed en masse these have a wispy ‘smoke-like’ appearance, hence the common name “smoke tree”) which surround the small (2–3 mm or 1⁄16–1⁄8 in) drupaceous fruit that develop.

II. How to Grow and Care

Sunlight

Smoke tree needs lots of sunlight to survive. Plant it where larger trees won’t obstruct its access to daylight. Anything less than full sun results in less foliage that isn’t as vibrant.

Temperature and Humidity

Smoke bush does best in moderate temperatures and average to dry humidity levels. In moist, very warm climates, fungal diseases are often a problem. In colder climates, winter winds can damage the plants, so they should be planted in sheltered conditions in these regions.

Watering

Young plants should be watered deeply and regularly twice a week, but once established, smoke bush has good resistance to drought and dry conditions. Mature plants can thrive nicely if watered moderately every 10 days during the active growing season.

Soil

Smoke bush does well in nearly all soil conditions provided the soil is well-drained. It does not tolerate poorly draining or soggy soils.

Fertilizing

Smoke bush does not require much feeding. Fertilize it in spring or add a layer of compost. An annual application of organic plant food may be called for if the shrubs are not growing vigorously. The bush might need nitrogen to fuel the growth of its foliage.

Planting Instructions

Container-grown smoke trees are best planted in spring, but they also can be planted in fall. Dig a hole twice the width and the same height as the root ball in well-draining soil. Don’t add any fertilizer when planting, as it can burn the roots. Loosen the roots with your hands before planting. Set the plant in the hole and backfill the hole halfway. Tamp down the soil to remove air bubbles and repeat the process with the other half of the hole. After the soil is firm, build a 3-inch ring of soil outside the root ball to contain water. Add 3-inches of mulch without letting any of it touch the trunk. Water deeply.

Pruning

A smoke bush has minimal pruning needs. You can prune it anytime to remove damaged branches, but late winter is the best time to prune severely to 6 to 8 inches above ground to reshape and rejuvenate the shrub. However, you will sacrifice flowers for the following year. If you wish to avoid the messy flowers, prune heavily in late winter/early spring to remove the flowering wood.

If you wish to encourage a tree-like growth habit, prune away all but one central leader stem, and keep pruning away any stems that reappear. A bushier shrub can be obtained by cutting all stems down to six inches above ground level in late winter for the first two or three years.

Propagation

Smoke tree can be propagated by stem cuttings or seeds.

  • Cuttings: Stem cuttings are the most common propagation method. Cut semi-hardwood cuttings (not new growth) about 6 to 8 inches long from a leafy stem. Remove the lower leaves and strip off a little bark at the end of the cutting. Dip the cutting in rooting hormone, place it in a well-draining medium, and cover it with a plastic bag supported by wooden stakes. Keep the medium moist and put the cutting in a warm place or on a heat mat. Check every week or so to see if the cutting is forming roots, either by tugging lightly on a leaf or seeing roots in the drain hole. When the cutting roots, remove the plastic bag. Transplant the new plant to the ground or a container after it develops a robust root system.
  • Seed: Buy or harvest smoke tree seed. Place these tiny seeds in a bowl of warm water for 12 hours. Change the water and place them back in the bowl for another 12 hours. Drain them and wait for them to dry completely. In the meantime, prepare a germination bed in full sun with well-draining soil. Add a 2-to-3-inch layer of sand to the bed and mix it into a depth of about 8 inches. Use your finger to push the dried smoke tree seeds about 3/8 inch into the bed, spacing them 12 inches apart. Water with a fine mist to avoid washing away the tiny seeds. It takes up to two years for smoke tree seeds to germinate.

Potting and Repotting 

Smoke bush has a nicely contained fibrous root system and is easy to transplant into a pot with these steps.

  • Root-prune the shrub several months before you plan to move it into a container. Do so by digging a 12-inch to 24-inch circle that is 14 inches deep, around the plant’s base.
  • At transplant time, dig down around the tree 12 to 14 inches and lift the root ball out of the ground.
  • Move the shrub to its new location. Avoid plastic and choose a pot that’s tall and sturdy to accommodate the tree’s growth and height. The pot should have at least one large drainage hole. Fill the pot with good, fertilized potting soil mixed with some sand and compost.
  • Place your potted smoke bush in a sunny area, and water fully to settle the roots.

Overwintering

Be careful not to overwater your smoke bush this time of year. Do not fertilize the bushes during the winter. Use around 3 inches of mulch around the bases of your outdoor plants to protect the roots.

Pests and Diseases

The oblique-banded leafroller, a native North American pest that feeds on a wide range of plants, can be a problem with smoke bush.

If soils are not well-drained, smoke bush is very susceptible to verticillium wilt—a browning of the leaves caused by the fungus Verticillium. It can also get scabs and leaf spot, a fungal condition prevalent in warmer weather. If you live in the eastern United States, watch out for stem canker.

III. Types of Smoke Bush

You’ll see four main types of smoke bush on the market. “Golden Spirit,” one of the most common, actually isn’t purple (the plant’s mainstay shade). Also known as “Ancot,” this iteration has lime green foliage in the summer and turns orange and red come fall—over time, it grows to 10 feet tall and six feet wide. “Grace” is even larger: It reaches 15 feet tall and wide, and boasts burgundy-purple foliage in the spring and summer months before transitioning to an orange-red in autumn.

Probably the most common, “Royal Purple” has red-purple foliage that turns scarlet in the fall; another large-scale plant, the variety grows 15 feet tall and 12 feet wide. For a touch of bronze, “Nordine” is a great choice. The burgundy-bronze plumes change to brilliant red and orange during the colder months and is similar to “Grace” in size. No matter the variety, however, you can count on these beauties for oval leaves, fall colorways, and frothy-pink clusters of summer blooms.

IV. Uses and Benefits 

  • Ornamental uses

Smoketree is recommended for growing in parks and scenic spots. It is a common choice because it grows well, even in difficult conditions, once it is established. It is often used in xeriscaping or as a screening plant. Prized also for its bright blooms, it is a good fit for rock and Mediterranean gardens. Its companion plants include the Black-eyed Susan for its brightness and ornamental grasses.

  • Dyestuff

The wood was formerly used to make the yellow dye called young fustic (fisetin), now replaced by synthetic dyes.

The species, along with other members of the sumac family, has been used to make red dyes for textiles including weft-wrapped soumak rugs and bags in the Middle East. The names sumac and soumak likely derive from the Arabic and Syriac word ܣܘܡܩܐ ‘summāq’, meaning “red”.

Smoketree (Cotinus coggygria) Details

Common name Common Smoketree, Smokebush, Smoketree
Botanical name Cotinus coggygria
Plant type Perennial
Hardiness zone 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b
Growth rate Fast
Height 10 ft. 0 in. - 15 ft. 0 in.
Width 10 ft. 0 in. - 15 ft. 0 in.
Sunlight Full sun (6 or more hours of direct sunlight a day)
Soil condition Clay
Flower color Gold/Yellow
Leaf color Blue