Kousa dogwood (Cornus kousa), also know as Japanese dogwood and Oriental dogwood, is a small-sized ornamental tree that belongs to the genus Cornus and family Cornaceae. This deciduous tree is a woody perennial with a life span of 5 to 20 years and is commonly grown for its year-round esthetic value.
Soil and Light
Native to East Asian regions of Korea, China, and Japan, this tree shows hardy growth in USDA zones 5 to 7. While planting it, keep in mind that the plant shows a strong preference to areas that receive full sunlight or those areas with partial shade. Find a well-drained area that has plenty of moisture and an acidic soil. Although these are the ideal conditions for their growth, these trees are also capable of growing in compacted, neutral or alkaline, and dry soils.
Water and Temperature
The kousa dogwood tree has a low requirement for water. Do remember to irrigate it during the dry and hot spells in summer. This is important as the leaves of this tree are highly susceptible to scorching under hot conditions. Watering them sufficiently would help prevent this. An air temperature down to –14°F can be tolerated by this tree.
These trees prefer decomposing mulch to synthetic fertilizers. To promote root growth, avoid the use of nitrogen fertilizers in the first year after transplantation.
Expect the kousa dogwood to bloom anytime between late spring and early summer. The flowering extends over a period of at least 6 weeks. Prior to flowering, the tree produces red raspberry-like berries. When in bloom, the kousa dogwood foliage gives a show of white, which is actually attributable to its petal-like bracts than to its flowers. This tree is capable of growing to at least a height of 10 feet.
Prepare a seedbed and sow the seeds of dogwood during autumn, or go for stratification in spring. If it is summer, consider rooting of greenwood cuttings.
Kousa dogwood is especially sensitive to transplantation during autumn. Therefore, if you wish to transplant during autumn, ensure that you provide the plants with the required kind of soil, fertilize well, and mulch as necessary. In order to maximize the chances of survival during the first winter, take care to avoid winter salt spray.
Dealing with Disease and Pest Problems
The kousa dogwood is hardy and is affected by no serious diseases or pests. However, occasional cases of wood rot and decays, anthracnose, gray mold, basal rot, root rot, Phytophthora canker, and dogwood anthracnose have been reported.
- Rotting and decay of the wood could pose a serious danger when the rotten structures overhang homes. If you think that rotting has reached a point beyond control, remove the tree as soon as possible.
- When anthracnose affects your tree, immediately remove all the affected parts and generously apply fungicides.
- To prevent gray mold, use some fungicides that could help reduce chances of leaf, stem, and fruit infections.
- Reduce the quantity and frequency of watering and set the drainage right in order to successfully control basal rot, root rot, and canker.
- In case of dogwood anthracnose, immediately strip your tree of the infected foliage and destroy all the leaves as soon as possible.