Overview
Cotinus obovatus Raf., also known as American smoketree or American smokebush, is a species of small tree or large shrub that belongs to the family Anacardiaceae. This plant is native to the central and southeastern regions of the United States and can be found growing abundantly in moist soils along rivers and streams.
Appearance
American smoketree is a deciduous plant that can grow up to a height of 20 feet. It has a round crown and a diameter of up to 15 feet. The bark of the plant is rough and gray-brown in color. The leaves of American smokebush are simple, alternate, and have an oval to obovate shape. The foliage is green during the growing season and turns shades of orange, red, and purple in the fall.
One of the most distinctive features of this plant is its inflorescence. The flowers of American smoketree are small, greenish-yellow, and appear in late spring or early summer. They are arranged in a long, drooping panicle that can reach up to 8 inches in length. The panicle is covered in tiny hairs that give it a smoky, cloud-like appearance. This characteristic has earned the plant its common name "smoketree" or "smokebush."
After flowering, American smoketree produces small, dry fruits that are less than 1 inch in diameter. These fruits are a food source for many birds and other wildlife.
Uses
American smoketree is an ornamental plant that is commonly grown in gardens and parks for its attractive foliage and unique inflorescence. It is also used in landscaping as a hedge, screen, or accent plant.
In folk medicine, the bark and leaves of American smoketree have been used to treat a variety of ailments, including diarrhea, dysentery, and skin irritations. The bark contains compounds that have anti-inflammatory and antimicrobial properties. However, it is important to note that these uses have not been scientifically proven and should not be substituted for professional medical advice.
The wood of American smoketree is hard and dense, making it suitable for woodworking and carving. It has also been used as a source of dye.
Light Requirements
Cotinus obovatus, commonly known as American smoke tree, thrives in full sun to partial shade. This plant requires adequate sunlight for growth, and it should receive around 6 hours of direct sunlight per day. However, if grown in areas with high temperatures, it may require some shade during the hottest part of the day to prevent sun damage.
Soil Requirements
Cotinus obovatus grows best in well-drained soils that are rich in humus. The soil should have a pH range of 6.5 to 7.5, which is slightly acidic to neutral. If the soil is too alkaline, it may cause nutrient deficiencies. Therefore, it is recommended to amend the soil with organic matter such as compost or peat moss to improve the soil structure and nutrient content.
Temperature Requirements
American smoke tree is hardy in USDA zones 5 to 9 and can tolerate a wide range of temperatures. However, it prefers moderate temperatures and may suffer from heat stress during hot summers. The optimal temperature range for growth is between 50 to 80 °F (10 to 27 °C). Temperatures below freezing may cause damage to the plant, and it may require protection during winter months.
Cultivation Methods
Cotinus obovatus Raf. is a slow-growing, deciduous shrub that can reach a height of 10-15 feet and a width of 8-10 feet. It prefers full sun to partial shade, well-drained soil, and regular watering. The plant is hardy in USDA zones 5-9.
To grow Cotinus obovatus Raf., you should plant it in a location that receives at least 6 hours of direct sunlight per day. The soil should be well-draining, fertile, and rich in organic matter. You can amend the soil with compost, peat moss, or aged manure to improve its quality.
You can propagate Cotinus obovatus Raf. from softwood cuttings taken in late spring or early summer. Simply remove the lower leaves from a 4-6 inch stem, dip the base in rooting hormone, and plant it in a pot filled with a mix of perlite and peat moss. Keep the pot in a warm, humid place and mist the cutting regularly until it develops roots.
Watering Needs
Cotinus obovatus Raf. requires regular watering to establish itself in the first year of growth. After that, the plant is drought-tolerant and can survive on natural rainfall. However, it is best to water it deeply once a week during periods of prolonged drought or extreme heat.
The soil should be kept evenly moist, but not waterlogged. You can avoid overwatering by checking the top-inch of soil for dryness before watering. You should also water the plant at the base to avoid wetting the foliage, which can lead to fungal diseases.
Fertilization
Cotinus obovatus Raf. does not require frequent fertilization, but you can feed it with a balanced, slow-release fertilizer once a year in early spring. You can also amend the soil with compost or aged manure to improve its fertility.
Do not apply fertilizer in late summer or fall, as this can stimulate new growth that may not have time to harden off before winter. This can also make the plant more susceptible to cold damage.
Pruning
Cotinus obovatus Raf. requires minimal pruning to maintain its shape and size. You can prune it in late winter or early spring, before the new growth appears. Remove any dead, diseased, or damaged wood, as well as any crossing or rubbing branches.
You can also prune the plant to control its size, shape, or density. You can do this by cutting back up to one-third of the branches to encourage new growth. However, avoid pruning more than one-third of the plant at once, as this can shock it and stunt its growth.
Cotinus obovatus Raf. can also be trained to grow as a single-stemmed tree by removing the lower branches and allowing a central leader to develop. This can create a striking focal point in the landscape.
Propagation of Cotinus obovatus Raf.
Cotinus obovatus Raf., also known as American smoketree or Texas smoke tree, is a deciduous shrub or small tree native to the southeastern United States. The plant is known for its showy, smoke-like inflorescences that bloom in summer and fall. Propagation of Cotinus obovatus can be accomplished both by sexual and asexual methods.
Sexual propagation
The easiest way to propagate Cotinus obovatus sexually is through seed. Collect fresh seeds from the plant in autumn, before they start to disperse. The seeds are small and round, and they require no pretreatment before planting. Sow the seeds in a well-draining potting mix in pots or trays and cover them with a thin layer of soil. Keep the soil moist but not waterlogged and place the pots or trays in a warm, bright location. The seeds should germinate within two to four weeks. Once the seedlings have developed 2-3 true leaves, they can be transplanted into individual pots.
Asexual propagation
Cotinus obovatus can also be propagated asexually through stem cuttings. Take 4-6 inch (10-15 cm) long cuttings from the tips of healthy, vigorous shoots in early summer when the plant is actively growing. Remove the lower leaves and dip the cut end of the stem in rooting hormone. Insert the stem into a pot filled with a well-draining rooting medium such as perlite or vermiculite. Keep the soil moist and the cutting in a bright, warm location with high humidity. If the cutting is successful, it should take root within a few weeks. Once the cutting has developed roots, it can be transplanted into a larger pot or planted outside in a prepared bed.
Cotinus obovatus can also be propagated by layering. Bend a low-hanging branch of the plant to the ground and make a small cut in the bark where the branch meets the soil. Cover the cut with soil and anchor the branch in place. Keep the soil moist and wait for roots to develop at the cut site. Once the branch has developed a robust root system, it can be severed from the parent plant and planted elsewhere.
Disease and Pest Management for Cotinus obovatus Raf.
Cotinus obovatus Raf., commonly known as American smoketree or American smokebush, is a small deciduous tree or shrub that is native to North America. This plant is known for its stunning foliage that ranges from yellow-green to deep purple and bronze in the fall. While Cotinus obovatus Raf. is generally a hardy and disease-resistant species, it is still vulnerable to certain pests and diseases that can affect its growth and development.
Common diseases that affect Cotinus obovatus Raf.
One of the most common diseases that can affect Cotinus obovatus Raf. is Verticillium wilt. This is a fungal disease that affects many types of plants, including American smoketrees. Symptoms of Verticillium wilt include yellowing and wilting of leaves, stunted growth, and eventual death of the plant. There is no cure for this disease, and infected plants need to be removed and destroyed to prevent the spread of spores. To prevent the disease from occurring in healthy plants, it is recommended to plant Cotinus obovatus Raf. in well-draining soil, avoid overcrowding, and provide adequate nutrition and water.
Another fungal disease that can affect Cotinus obovatus Raf. is Powdery mildew. This disease is characterized by white, powdery growth on the leaves and stems of the plant. While it does not usually kill the plant, it can weaken it and make it more susceptible to other diseases and pests. Powdery mildew can be treated with fungicides, but prevention is the best course of action. To prevent powdery mildew, it is recommended to plant Cotinus obovatus Raf. in a location with good air circulation and avoid overhead watering.
Common pests that affect Cotinus obovatus Raf.
One of the most common pests that can affect Cotinus obovatus Raf. is the Smoketree borer. This insect lays its eggs on the trunk and branches of the plant, and the larvae burrow into the wood, causing extensive damage. Symptoms of Smoketree borer infestation include wilting, yellowing, and dieback of branches, and sawdust-like frass around the base of the plant. Infested branches need to be pruned and destroyed, and the remaining plant can be treated with insecticides to prevent further damage.
The other pest that can affect Cotinus obovatus Raf. is the Caterpillar. Caterpillars are the larvae of moths and butterflies and can feed on the leaves of American smoketrees. In small numbers, they may not cause significant damage, but in large numbers, they can defoliate the entire plant. Caterpillars can be controlled with insecticides, but it is recommended to use natural predators like birds, wasps, and ladybugs to control their population.
Proper care, including routine watering and feeding, mulching, and pruning, can keep Cotinus obovatus Raf. healthy and strong, making it less vulnerable to pests and diseases. Regular inspections of the plant for any signs of infestation or infection can help catch any issues early and prevent them from spreading.
