Redkan Dogwood (Cornus florida ‘Redkan’ or ‘Rubra’) is a distinguished flowering dogwood cultivar, valued for its ornamental appeal. This beautiful deciduous tree offers striking seasonal interest, making it a favored choice for enhancing outdoor spaces. This guide details how to cultivate a thriving Redkan Dogwood.
Understanding Redkan Dogwood’s Key Features
The Redkan Dogwood matures into a small tree, typically 20 to 30 feet tall with a 25 to 30-foot spread, often wider than tall. Its growth habit features a rounded crown and branches that develop distinctive horizontal tiers with age. The most celebrated feature is its showy bracts, often mistaken for petals. These deep reddish-pink structures surround the small, yellowish-green true flowers, creating a vibrant spring display.
Throughout the growing season, its ovate, dark green leaves are typically 3 to 6 inches long. In autumn, these leaves turn a rich reddish-purple or maroon, providing significant fall color before dropping. Mature bark develops an interesting, blocky pattern, adding visual texture even in winter. This combination of spring blooms, summer foliage, fall color, and winter bark ensures year-round aesthetic appeal.
Successful Planting and Ideal Growing Conditions
Establishing a Redkan Dogwood begins with selecting an appropriate site. This tree flourishes in partial shade, ideally with morning sun and protection from intense afternoon heat. Too much direct sunlight, especially in warmer climates, can stress the plant and lead to leaf scorch. Redkan Dogwood is well-suited for USDA hardiness zones 5 through 9.
The soil composition is important for healthy growth. Redkan Dogwood prefers well-drained, acidic soil rich in organic matter, with a pH range of 5.5 to 6.5. If the soil is heavy clay or poorly drained, amending it with organic compost improves drainage and nutrient content.
When planting, dig a hole twice as wide as the root ball but only as deep. Place the tree in the center, ensuring the top of the root ball is level with or slightly above the surrounding soil grade. Backfill gently, firming the soil around the roots to remove air pockets. After planting, thorough watering is important to settle the soil and provide initial moisture, especially during the first one to two growing seasons for root establishment.
Ongoing Care and Maintenance
After establishment, Redkan Dogwoods need continued attention. Watering shifts from daily to deeper, less frequent applications, especially during dry spells. As shallow-rooted trees, they benefit from regular moisture, particularly in hot summer months.
Fertilize thoughtfully, as excessive amounts harm the tree. For established trees, apply a balanced slow-release fertilizer in early spring. Do not fertilize young trees during their first year, allowing roots to establish naturally. Soil testing can identify specific nutrient deficiencies.
Pruning maintains tree health and shape. The best time is during dormancy: late fall, winter, or early spring before new growth. Remove dead, diseased, or damaged branches, and suckers from the trunk base. Thinning crossing branches improves air circulation, preventing disease.
Apply a 2 to 4-inch layer of organic mulch (pine straw or bark chips) around the tree base. Mulch retains soil moisture, regulates temperature, and suppresses weeds. Keep mulch a few inches from the trunk to prevent moisture buildup and rot.
Troubleshooting Common Issues
Redkan Dogwoods can encounter various issues, though many are manageable with proper care. Pests like dogwood borers and scale insects can affect the tree. Borers feed beneath the bark, causing branch dieback, especially in stressed trees. Scale insects suck sap from leaves and shoots, leading to stunted growth. Regular monitoring and maintaining tree vigor are the first lines of defense.
Diseases like powdery mildew and anthracnose are common fungal problems. Powdery mildew appears as a white coating on leaves, especially in humid conditions with poor air circulation. Anthracnose causes dark spots on leaves and flower bracts, potentially leading to leaf blight and twig dieback, particularly in wet spring weather. Proper spacing, good air circulation, and promptly removing infected plant debris help manage these diseases.
Environmental stress can also manifest in various symptoms. Leaf scorch, browning along leaf edges, occurs with drought or excessive sun exposure, especially if newly planted. Adequate watering during dry periods and providing partial shade can mitigate this. Nutrient deficiencies might cause yellowing leaves, indicating a need for soil testing and targeted fertilization. Transplant shock, common after planting, can be minimized with consistent moisture and careful handling.