Smoke bush, Cotinus coggygria, is a deciduous shrub or small tree often used as a garden specimen thanks to its beautiful purple-pink smokey plumes and the purple leaves found on some cultivars.
Smoke bush has an upright, multi-stemmed habit. The leaves are waxy green except for those cultivars with purple leaves. Ovate-shaped leaves grow up to 3 inches long, turning yellow, orange, or purplish-red in fall, depending on the variety. The name "smoke bush" derives from billowy hairs attached to the flower clusters, which remain in place through the summer, turning a smoky pink to purplish-pink as the weeks progress.
Plant the bush outdoors in the spring or the fall. This type of shrub has a medium growth rate, which means it will grow about 1 to 2 feet a year. The bush is mildly toxic to humans, and the sap can cause skin irritation.
|Common Names||Smoke bush, royal purple smoke bush, smoke tree, European smoketree, Eurasian smoketree, Venice sumach, dyer's sumach|
|Botanical Name||Cotinus coggygria|
|Plant Type||Deciduous shrub|
|Mature Size||10-15 ft. high, similar spread|
|Sun Exposure||Full sun|
|Soil Type||Prefers well-drained, loamy soil|
|Soil pH||Tolerates both acidic and alkaline soils|
|Bloom Time||Late spring to mid-summer|
|Hardiness Zones||4-9 (USDA)|
|Native Area||Southern Europe to central China|
|Toxicity||Mildly toxic to humans|
Watch Now: How to Grow and Care for a Smoke Bush
Smoke Bush Care
Smoke bush is often used as an individual specimen plant, and in larger landscapes, it can be massed or planted as an informal screening hedge. Once established, the plant is drought-tolerant, so it's useful in xeriscaping and other applications where water conservation is important. Purple smoke bush is dioecious, meaning it has staminate and pistillate (male and female) flowers borne on different individuals.
The plant does well in almost any soil type and most any pH level. The ideal circumstance is slightly sandy loam, but they also do well in rocky soils. In zone 5, plant them in slightly sheltered locations to protect them from winter winds. When grouping these plants, they should be spaced 10 to 15 feet apart.
Add a 2-inch layer of mulch for young shrubs using wood chips or bark mulch to keep weeds away and the soil moist. Make sure to keep mulch about two inches away from the truck of the plant.
Smoke bush should be planted in full sun. If it's planted In part shade conditions, foliage will be sparse and will require regular pruning to keep the plants dense.
Smoke bush does well in nearly all soil conditions provided the soil is well-drained. It does not tolerate poorly draining or soggy soils.
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.
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.
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.
Types of Smoke Bush
- 'Daydream' is a good green-leaved cultivar with dense, creamy blooms. It is a somewhat smaller plant that grows to a maximum of 10 feet wide and tall.
- 'Nordine' is a very hardy purple-leaved variety. It has yellow-orange fall foliage.
- 'Royal Purple' is a common purple-leaved form with dark foliage and purple-red "smoke."
- 'Velvet Cloak' is another dark purple-leaved form with dramatic orange-red fall color.
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 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.
Propagating Smoke Bush
Propagate smoke bush by stem cuttings and planting seeds. Stem cuttings are preferred because the results will duplicate the unique ornamental character displayed by its parent plant. To propagate smoke bush by stem cuttings, follow these steps:
- In the summer, choose a leafy stem the length of your hand. Select new softwood cuttings.
- Strip the stem of its lower leaves.
- Dip the cutting in rooting hormone.
- Embed the stem in a well-draining growing medium.
- Cover the pot loosely with a plastic bag to keep the stem and potting mix moist.
- Transfer to a larger pot or the ground when the stem develops roots.
Potting and Repotting Smoke Bush
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 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.
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.
Common Pests & Plant 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.
Is smoke bush easy to care for?
The smoke bush doesn't require much care. But when this bush is used as a specimen plant, a dramatic accent in a garden, or in a pot near an entryway as a focal point, be sure to give it some attention to keep it looking good.
How long will a smoke bush live?
A smoke bush can live a long life—for approximately two decades—if it is kept out of rich soil.
Do smoke bushes attract pollinators?
The flowers and anthers of the smoke bush plant attract honey bees. But they won't stay long since the wispy flowers don't yield much nectar or pollen.
Cotinus Coggygria. Missouri Botanical Garden
Hall, Carol W., and Norman E. Hall. Timber Press Guide to Gardening in the Pacific Northwest. Timber Press, 2008