Kousa Dogwood, also known as Cornus kousa, is a small deciduous flowering tree or multi-stemmed shrub. It is native to East Asia, including Korea, China and Japan. Widely cultivated as an ornamental, it is naturalized in New York State. This plant is commonly used in landscaping as a specimen tree or in shrub borders. It is also a great plant to attract birds to the garden.
On average, Kousa Dogwoods grow at a slow-to-medium rate of 1-2 feet per year and reach a height of 20-30 feet tall. Initially of an upright habit, they spread out in maturity to a full width of 16-30 feet. In the right conditions they may live for more than 100 years. The bark is generally grayish-brown in color. As the tree ages, the bark begins to peel, revealing a lighter color underneath. The tree has a horizontal branching habit that makes the tree an ideal counterpoint for vertical structures.
The leaves are simple, ovate to elliptic, and have an opposite arrangement on the branches. They are about 2 to 4 inches long. The leaves are green in color during the growing season, with a smooth texture and a glossy appearance. The leaf margins are smooth and do not have serrations or lobes. In the fall, the leaves turn from green to a vibrant mix of colors including red, purple, and scarlet.
The flowers of the Kousa Dogwood are not actually flowers, but rather modified leaves called bracts. These bracts are showy and resemble petals. The bracts are white, although some cultivars may have pink or red bracts. They are arranged in a star-shaped pattern around the center of the tree. The actual flowers are small and inconspicuous, located at the center of the bracts. They are usually yellow or greenish-yellow and have a light, sweet scent.
The blooms appear in late spring, after the leaves have fully emerged. The bracts last for several weeks. The flowers are followed by small, berry-like fruits that ripen in late summer or early fall. These fruits are red or pink in color and are a favorite food of birds and other wildlife. The fruits are also edible and have a sweet, creamy flavor.
Kousa Dogwood is a hardy plant, resistant to dogwood anthracnose disease, unlike its relative Cornus florida. It is also tolerant to cold, deer, dogwood anthracnose, dogwood borers, frost, and powdery mildew. It prefers well-drained, acidic soil and can thrive in full sun to partial shade.
This Dogwood is well-suited to USDA Hardiness Zones 5 to 8. It can thrive in a wide range of climates, from the cooler areas of the Northeast and Midwest to the warmer regions of the South and Pacific Northwest.
Key Characteristics
- Appearance: Grows 15-30 feet tall and wide with a vase-shaped to rounded form.
- Flowers: Blooms later usually in late spring to early summer. The flowers are small and greenish-yellow, surrounded by four showy white to pink bracts.
- Leaves: The leaves are elliptic to ovate, medium to dark green in summer, and turn shades of red and purple in the fall.
- Bark: The bark is mottled, exfoliating, and has a tan and brown color.
- Fruit: Produces raspberry-like, red to pink edible drupes in late summer to fall. These fruits are attractive to birds and wildlife.
Cultivars of Kousa Dogwood
- ‘Milky Way’: This cultivar has large, white blooms.
- ‘Wolf Eyes’: Has variegated foliage with creamy white margins and a splash of green in the center.
- ‘Gold Cup’: As the name suggests, this cultivar has golden-yellow streaks in the center of its green leaves.
- ‘Heart Throb’: Has deep pink flowers and heart-shaped bracts.
- ‘Satomi’: This cultivar has large, pink flowers that are sure to catch the eye. The foliage also turns a shade of red in the fall.
- ‘Little Beauty’: This dwarf cultivar features white flowers and red fruits.
- ‘Lustgarten Weeping’: This cultivar has a weeping habit and grows to about 6-10 feet tall.
- ‘Blue Shadow’: This cultivar features blue-green foliage and white flowers.
Interesting facts about Kousa Dogwood
- It is more cold hardy and disease resistant than the native flowering dogwood. It is also somewhat drought resistant and can grow in a variety of soil types.
- It has edible fruit. The fruit is about the size of a large raspberry and has a unique flavor that is often described as a cross between a mango and a strawberry. The fruit is often used in jams, jellies, and desserts in Asian cuisine.
- It starts off with a vase-shaped habit and becomes more rounded with age, with prominently layered branching.
Growing Conditions
- Climate: It thrives in zones 5-8 (USDA Hardiness Zone Map), similar to the Flowering Dogwood, but it’s generally more tolerant of heat and humidity.
- Light: Prefers full sun to partial shade. It can handle more sun than the Flowering Dogwood.
- Soil: Like the Flowering Dogwood, it prefers acidic, well-drained, fertile soil.
Care and Maintenance
- Watering: Regular watering, especially during the first few years after planting, is important. Established trees are more drought tolerant but will benefit from deep watering during dry periods.
- Mulching: Apply a 2-3 inch layer of mulch around the base of the tree to retain moisture, suppress weeds, and regulate soil temperature.
- Pruning: Minimal pruning is necessary. Prune in late winter or early spring before new growth appears to remove dead, diseased, or crossing branches to maintain the tree’s shape.
- Pests and Diseases: The Kousa is generally more disease-resistant, although it can still be susceptible to some issues like anthracnose and fungal diseases.