Cornus florida f. rubra, commonly known as pink dogwood, is a deciduous ornamental tree that typically grows between 15 and 30 feet tall. These trees produce pink flowers in early spring and small clusters of red berries that attract birds in the summer. The dark green foliage turns red or purple for a colorful fall display. Lower branches often droop over time while upper branches remain upright. This characteristic branching structure adds winter interest to the garden.
Pink dogwoods perform best in USDA hardiness zones 5b through 7b. They often grow taller and produce fewer flowers when grown in the warmer and more humid conditions of zones 8 and 9. Temperatures reaching -15 degrees F in the winter can cause bud damage and weaken the tree, making it susceptible to attacks by pests and disease.
Pink dogwoods tolerate a variety of well-drained soil types, but prefer a slightly acidic, nutrient-rich soil with a pH of 5.2 to 6.0. Incorporate 2 to 4 inches of pine bark or compost into the first 12 inches of soil prior to planting. Provide a 3-inch layer of mulch around the base of the tree to retain moisture and keep soil temperatures low. This helps keep the tree healthy and reduces the probability of attacks by pests such as dogwood borers.
Pink flowering dogwoods grow in sun or shade, but prefer partial shade and protection from hot afternoon sun, especially in southern climates. Flowering dogwoods planted in full sun or full shade flower less frequently than those planted in partial shade. Planting dogwoods in full sun can weaken the tree and encourage attacks by dogwood borers.
Newly-planted pink dogwoods and those planted in full sun require regular watering. Dogwoods typically need 1 inch of water per week. If natural rainfall does not supply this amount of water, provide irrigation. Avoid watering dogwoods with sprinklers, or plant in a location that receives eastern morning sun to promote quick drying of foliage. Avoid over watering. Fungal diseases such as anthracnose and powdery mildew thrive in wet conditions.
Young dogwoods can suffer injury from over-fertilization, so avoid feeding during the tree's first year. This will allow time for the root system to become established and for the tree to adapt to the climate and soil conditions. After the tree has grown to a height of 6 feet, apply a slow-release granular fertilizer. Sprinkle it over a 100-square-foot area around the tree. Fertilizers high in nitrogen promote succulent growth that may encourage the development of powdery mildew. If you plant your pink dogwood near a fertilized lawn, it rarely requires additional fertilization. The dogwood's shallow root system will absorb nutrients from the lawn.