Overview of Cotinus obovatus
Cotinus obovatus, also known as American Smoketree, is a deciduous shrub or small tree that is native to the southeastern United States. It is a member of the Anacardiaceae family and is closely related to other species of smoke trees and poison ivy.
Common Names of Cotinus obovatus
The common names of Cotinus obovatus vary depending on the region and include American Smoketree, Smoke Bush, Smoke Tree, and Chittamwood. It is called American Smoketree due to its unique foliage, which appears as a gray smoke-like haze in late summer and fall.
Appearance of Cotinus obovatus
Cotinus obovatus grows as a small tree or large shrub, typically reaching heights between 6-20ft. Its leaves are oval-shaped, about 3-6 inches long, and have a glossy dark-green color in the summer. In the fall, the leaves change to a beautiful range of colors, including red, pink, orange, and yellow. The flowers of the plant are small, greenish-yellow, and insignificant. However, the fruit is a hard, brown nut-like capsule that is covered with fine hairs, which give the appearance of smoke when they are caught by the wind.
Uses of Cotinus obovatus
Cotinus obovatus is primarily grown as an ornamental shrub due to its stunning foliage and unique appearance. It is also used for erosion control and provides a valuable habitat for wildlife. Historically, the bark and wood of the Chittamwood variety of the plant were used in the construction of baskets, bows, and other crafts by Native American tribes.
Although Cotinus obovatus is not typically used for medicinal purposes, it does contain compounds that have been used topically to treat skin conditions such as rashes and boils. However, it is essential to note that the plant can be toxic if ingested, and caution should be taken when handling it.
Light Requirements
Cotinus obovatus prefers full sun exposure but can tolerate light shade. In areas with intense heat, it may require some shade during the hottest part of the day.
Temperature Requirements
Cotinus obovatus grows well in moderate temperatures between 60°F to 85°F (15°C to 29°C). It can tolerate short-term temperature extremes of up to 5°F (-15°C to 35°C).
Soil Requirements
Cotinus obovatus requires well-draining acidic soil with a pH of 4.5 to 5.5. The plant can tolerate a range of soil textures, from sandy to loamy soils. It does not thrive in poorly-draining or compacted soils.
The plant prefers soils that are rich in organic matter, such as leaf mold or compost. When preparing the soil for planting, it is recommended to add organic matter and mix it well before planting.
Cotinus obovatus is also tolerant of drought, but for optimal growth, it needs moderate moisture. Overwatering or waterlogged soil can contribute to root rot, which may eventually kill the plant.
Cultivation Methods
Cotinus obovatus, commonly known as the American smoke tree, is a deciduous tree that can thrive in USDA hardiness zones 5 to 9. It prefers full sun but can tolerate partial shade. This tree grows best in well-drained soil with a pH range of 6.0 to 7.5.
When planting, ensure to dig a hole that is wider and deeper than the root ball. Mix some organic matter with the soil and backfill the hole, gently firming it around the roots. Water the tree thoroughly.
Watering Needs
Cotinus obovatus requires moderate watering, especially during dry spells. This tree does better in soil that is slightly moist than in soil that is waterlogged or too dry. Ensure to water the tree deeply once a week if you experience an exceptionally dry period.
Watering should be done in the morning or late evening, and avoid wetting the leaves. Over-watering could lead to root rot and other fungal issues.
Fertilization
Adding compost or manure to the soil around the base of the tree can improve soil fertility. Cotinus obovatus does not require excessive fertilizer. It is best to apply a balanced fertilizer once a year.
Applying too much fertilizer can lead to excessive growth and weakens the tree structures.
Pruning
Cotinus obovatus requires minimal pruning, just to maintain a pleasing shape or remove dead or damaged limbs. This tree blooms on old wood, so avoid pruning in winter or early spring, as it could remove some of the flower buds. Low hanging branches and suckers should be removed to keep the base of the tree clean.
Pruning should be done in early summer, after the tree finishes blooming, or late fall, after the leaves have fallen. Sharp pruning tools should be used to avoid causing excess damage to the tree.
Propagation of Cotinus obovatus
Cotinus obovatus, commonly known as American smoke tree, is a small deciduous tree that is native to the southeastern United States. It is often grown for its attractive foliage, which includes shades of purple, red, and yellow in the fall. Propagating Cotinus obovatus can be done through several methods, including seeds, cuttings, and grafting.
Seed Propagation
Cotinus obovatus can be propagated by seed. The seeds should be collected in the fall when the fruit has turned brown and is dry. The seeds should then be stored in a cool, dry place until they are ready to be planted in the spring. Before planting, the seeds should be soaked in warm water for 24 hours to help soften the seed coat, which will promote germination. The seeds can then be planted in a seed tray filled with a well-draining potting mix. Keep the soil moist and place the tray in a warm spot with bright, filtered light. Germination can take several weeks to a few months.
Cutting Propagation
Cutting propagation is another effective method for propagating Cotinus obovatus. The best time to take cuttings is in the summer when the plant is actively growing. Select healthy, new growth and make a clean cut just below a node. Remove the lower leaves and dip the cutting in rooting hormone. Plant the cutting in a well-draining potting mix and water well. Cover the pot with a plastic bag to maintain high humidity and place it in bright, filtered light. The cutting should form roots in 2-3 months.
Grafting Propagation
Grafting is a more advanced method of propagating Cotinus obovatus. It involves combining two different plant varieties to create a new plant with desirable traits. The process involves taking a cutting from a desired plant and attaching it to the root system of another related plant. This technique is often used to propagate older trees and to ensure the genetic consistency of the plant. Grafting should only be attempted by experienced gardeners or professionals.
Disease Management:
Cotinus obovatus, commonly known as American smoketree, is a relatively hardy plant species with no known major diseases. However, the plant is susceptible to some fungal diseases that are generally caused by damp weather or poor drainage. These diseases may include powdery mildew, verticillium wilt, and botryosphaeria canker.
If the plant is affected with powdery mildew, prune all infected parts and spray a potassium bicarbonate solution to control the spread. For verticillium wilt, apply a soil treatment with a fungicide containing thiophanate methyl. For botryosphaeria canker, prune all affected parts and apply a fungicide containing copper or chlorothalonil.
Pest Management:
Cotinus obovatus is generally not troubled by many pests. However, some insects can pose a significant threat to the plant's health, including caterpillars, spider mites, and scale insects. These pests can cause defoliation and even death of the plant if left uncontrolled.
To control caterpillars, handpick them or use a biological control product containing Bacillus thuringiensis. For spider mites, apply a forceful water spray to the foliage to remove the pests. Alternatively, you can use insecticidal soap or neem oil to control their spread. For scale insects, prune all heavily infested parts, and apply a horticultural oil spray to control the remaining ones.
Regular maintenance practices such as cleaning up garden debris, practicing good sanitation measures, and providing optimal growing conditions can help to prevent disease and pest infestations in Cotinus obovatus.
