The Dogwood (Cornus) is a prized ornamental tree known for its stunning spring flowers and rich autumn color. For gardeners looking to expand their landscape or preserve a favorite specimen, propagation is achievable. Understanding the tree’s biological requirements allows you to successfully create new, genetically identical copies or grow new individuals from seed.
Propagating Using Stem Cuttings
Propagating Dogwoods using stem cuttings is the most reliable method for cloning the parent tree, which is important for named cultivars. Success comes from taking softwood cuttings, harvested from the current season’s growth during late spring or early summer, typically after flowering. The ideal time is when the new stem is firm enough to snap when bent, but has not yet become woody.
Cuttings should be taken in the early morning, selecting healthy, non-flowering shoots three to six inches long. Make a clean cut just below a leaf node. Remove all but the top one or two leaves to reduce moisture loss.
To stimulate root development, dip the cut end into a rooting hormone, preferably one with a higher concentration of IBA for species like Cornus florida. Insert the cutting into a sterile, well-draining medium, such as perlite and peat moss or sand and coir. Avoid heavy potting soil, which can lead to stem rot.
Cuttings require high humidity to prevent drying out, achieved by covering the pot with a clear plastic bag or dome. Place the container in bright, indirect light and maintain consistent moisture. Roots often begin to form within six weeks.
Growing Dogwoods From Seed
Growing Dogwoods from seed is time-consuming and should be used primarily for native species, since hybrid cultivar seeds may not produce the parent’s desired characteristics. Harvest the seeds from the bright red fruit in the autumn and clean off all the surrounding pulp. This pulp contains germination inhibitors that prevent premature sprouting.
Dogwood seeds require cold, moist stratification to simulate a winter cycle and break natural dormancy. To stratify artificially, mix the cleaned seeds with a damp substrate (sand, peat moss, or vermiculite) in a sealed plastic bag. Keep this mixture consistently moist but not saturated to prevent mold growth.
Place the prepared seeds in a refrigerator at about 40°F for 90 to 120 days. This cold treatment prepares the embryo for germination. Once stratification is complete, typically in late winter or early spring, the seeds are ready to be planted.
Sow the seeds about a half-inch deep in a container filled with potting mix. Place the container in a sheltered spot that receives partial sunlight and keep the soil consistently moist. Seedlings must establish a robust root system for at least one full growing season before being moved to a permanent location.
Essential Steps for Successful Transplanting
The transition from propagation to the open garden requires careful management for the young Dogwood’s survival. Before planting, rooted cuttings and established seedlings must undergo “hardening off,” which gradually exposes them to outdoor conditions like sun, wind, and fluctuating temperatures. This involves moving the container to a sheltered outdoor spot for a few hours daily over one to two weeks, increasing exposure time.
The ideal time for transplanting is during the tree’s dormant season (late fall or early spring) when the air is cool and the soil is moist. Select a site that offers partial shade, as Dogwoods are naturally understory trees that struggle in intense, all-day sun. The location must have well-draining, slightly acidic soil, ideally between pH 5.5 and 7.0.
Dig a planting hole twice as wide as the root ball but no deeper, ensuring the root flare sits slightly above the grade. After planting, water thoroughly to settle the soil and eliminate air pockets. Apply a two- to three-inch layer of organic mulch around the base to retain moisture, keeping it away from the trunk to prevent disease.