Kousa dogwood (Cornus kousa) is a small deciduous tree or large shrub native to eastern Asia. It is widely planted for its showy white or pink flowers and colorful red fruits. The plant is pollinated by bees and other insects, which transfer pollen from the male flower parts (anthers) to the female flower parts (stigma) to fertilize the egg cells.

Pollination mechanism

The flowers of Kousa dogwood are small and arranged in dense clusters (inflorescences) on the branches. Each individual flower has four white or pink petals and four green sepals surrounding a central cluster of yellow anthers and a single stigma. The anthers produce pollen, which is transferred to the stigma by insects when they land on the flower to collect nectar or pollen. The stigma, in turn, receives the pollen and transports it to the ovary where fertilization occurs.

Pollination agents

The primary pollinators of Kousa dogwood are bees, including honeybees, bumblebees, and solitary bees. Other insect pollinators include wasps, flies, and butterflies. These pollinators are attracted to the flowers by their bright colors, sweet nectar, and strong fragrance. The flowers bloom in late spring or early summer and are most attractive to pollinators during sunny, warm weather.

Effect of pollination on fruit production

Kousa dogwood produces small, edible red fruits (drupes) in late summer or early fall. These fruits ripen and are ready for harvest about 4-6 weeks after pollination. If the flowers are not pollinated, the fruits will not develop and will fall off the tree prematurely. Therefore, proper pollination is essential for fruit production in Kousa dogwood.

Cross-pollination

Kousa dogwood can be cross-pollinated with other varieties of dogwood, such as Cornus florida, which is native to North America. Cross-pollination can increase genetic diversity and lead to the development of new cultivars with desirable traits.

Kousa Dogwood (Cornus kousa) FAQ

What is a Kousa Dogwood?

A Kousa Dogwood is a small to medium-sized deciduous tree that is native to Japan, Korea, and China. It is known for its showy white or pink flowers in the spring and its strawberry-like fruits in the summer.

How tall does a Kousa Dogwood grow?

A Kousa Dogwood can grow to be 15-30 feet tall and wide at maturity.

What are the growing conditions for a Kousa Dogwood?

A Kousa Dogwood prefers well-draining soil with a neutral to slightly acidic pH, and partial to full sun exposure. It can also tolerate some shade.

When do Kousa Dogwoods bloom?

Kousa Dogwoods typically bloom in late May to early June.

What do Kousa Dogwood flowers look like?

Kousa Dogwood flowers are star-shaped and come in shades of white or pink. They have four to seven bracts that surround the actual flower.

When do Kousa Dogwood fruits ripen?

Kousa Dogwood fruits ripen in late summer to early fall.

What do Kousa Dogwood fruits taste like?

Kousa Dogwood fruits are edible and have a sweet, tropical flavor similar to a mango or pineapple.

How do I propagate a Kousa Dogwood?

Kousa Dogwoods can be propagated by seeds or cuttings. Seeds should be stratified (cold treated) before planting, and cuttings should be taken from semi-hardwood in the summer and treated with hormone rooting powder.

Are Kousa Dogwoods susceptible to any diseases or pests?

Kousa Dogwoods can be susceptible to anthracnose, powdery mildew, and root rot. They may also be affected by borers, scale, and leaf miners. Proper maintenance and care can help prevent these issues.

Planting and Care for Kousa Dogwood (Cornus kousa)

Planting

The Kousa Dogwood is best planted in the spring or fall, but can also be planted in the summer as long as it is well watered. Follow these steps for successful planting:

1. Choose a location with well-draining, moist, and acidic soil (pH 5.5-6.5) that receives partial shade or full sun.
2. Dig a hole twice as wide and as deep as the root ball of the plant.
3. Add organic matter such as compost or peat moss to the soil and mix well.
4. Place the plant in the hole at the same depth as it was in the container or nursery.
5. Backfill with soil and press firmly around the plant.
6. Water thoroughly to settle the soil.
7. Mulch around the base of the plant with 2-3 inches of organic material to retain moisture and suppress weeds.

Care

With proper care, your Kousa Dogwood will thrive:

• Water regularly, especially during the first year after planting. Keep the soil moist but not waterlogged.
• Fertilize with a balanced fertilizer in early spring before new growth begins.
• Prune in late winter or early spring to maintain the desired shape and remove any dead or diseased branches.
• Protect from pests and diseases such as powdery mildew, borers, and scale insects.
• Monitor for signs of stress such as wilting or discoloration and address promptly.