Dogwood propagation involves creating new plants from an existing tree, which is a common practice for maintaining desirable characteristics in popular varieties, such as the flowering dogwood (Cornus florida). Propagating allows home gardeners to multiply their stock. This multiplication can be achieved through two primary methods: taking cuttings from new growth or starting the process from the tree’s seeds. Both approaches generate new dogwood specimens, though they differ significantly in speed and complexity.
Propagation from Softwood Cuttings
Propagating dogwood using softwood cuttings is the quickest and most successful method for replicating a specific cultivar. The ideal time to take these cuttings is in late spring or early summer, just after the tree has finished blooming and the new shoots are still flexible. You can confirm the stem is ready by bending it; if it snaps, it is likely too woody, while a stem that is too limp may wilt before rooting.
Select healthy, non-flowering shoots from the current season’s growth and cut segments that are approximately 3 to 5 inches (8 to 13 cm) long. Make the final cut just below a leaf node, the point where the leaves attach to the stem, as this area contains a higher concentration of growth hormones. Remove all but the top two leaves to reduce the plant’s surface area for water loss, which helps prevent the cutting from drying out.
Preparing and Planting Cuttings
The exposed base of the cutting must be treated with a rooting hormone to stimulate root formation before the end of the stem dries out. After dipping the bottom inch of the stem into the hormone, gently tap off any excess powder before inserting it into the rooting medium. A well-drained, sterile medium is required, typically a mixture of half peat moss and half perlite, because traditional potting soil retains too much moisture and can cause the tender stem to rot.
Insert the prepared cuttings into the medium so at least one node is buried, then water gently to settle the mixture around the stems. To maintain the high humidity necessary for survival, cover the container with a plastic dome or a clear plastic bag to create a mini-greenhouse environment. Place the container in a location that receives bright, indirect light; roots should begin to form within four to six weeks, at which point the plastic covering can be removed.
Starting Dogwoods from Seed
Starting dogwoods from seed is a longer, more involved process, often used when propagating native species rather than named cultivars, as the resulting seedlings may not possess the same characteristics as the parent tree. The process begins with collecting the small, red fruits in the fall and cleaning the seeds by removing all the fleshy pulp. This pulp contains germination inhibitors that must be scrubbed away to allow the seed to sprout successfully.
Once cleaned, dogwood seeds exhibit a natural dormancy that requires cold, moist stratification to mimic the winter conditions they would experience outdoors. This treatment is necessary to break the seed’s dormancy and prepare the embryo for germination. The seeds need a chilling period of 90 to 120 days at temperatures consistently between 35 and 40 degrees Fahrenheit (2 to 4 degrees Celsius).
Stratification and Planting
Gardeners often achieve stratification by placing the cleaned seeds in a plastic bag mixed with a slightly damp medium like sand, peat moss, or vermiculite, ensuring the mixture is moist but not soaking wet. The sealed bag is then stored in a refrigerator for the required time, usually from late fall through early spring. This cold, moist environment primes the seed for growth.
After stratification, the seeds are ready to be planted in a sterile, well-draining seed-starting mix, typically sown about a quarter-inch to a half-inch deep. Germination will occur once the soil warms. Young seedlings require a few years of attentive care before they are large enough to be considered established trees, making this method significantly longer than propagation from a cutting.
Essential Care After Rooting
Once the dogwood cutting has formed a healthy root system or the seed has germinated, the new plant must transition from its protected environment. The roots of a cutting will resist a gentle tug when they are established, and a seedling will show steady new growth. The first step in promoting long-term survival is a gradual process called “hardening off,” which slowly acclimatizes the young plant to outdoor conditions like direct sunlight and wind.
Begin the hardening off process by placing the container in a sheltered, shaded outdoor spot for just one to two hours a day, then return it to its protected location. Over the course of seven to fourteen days, gradually increase the plant’s exposure time and move it into brighter light and more open areas. This slow adjustment allows the plant to better regulate water loss and withstand the stresses of the garden environment.
When the young dogwood is fully hardened off, it can be transplanted into a larger container or its final spot in the garden, ideally in the spring or fall when temperatures are moderate. The planting site should offer well-draining soil and afternoon shade, especially in warmer climates, as dogwoods naturally prefer an understory environment. Newly planted dogwoods have shallow root systems and require consistent moisture, so water them deeply one to two times a week during their first year.
For the first growing season, newly transplanted dogwoods benefit from a light application of a balanced, slow-release fertilizer in the spring to support root and shoot development. In regions with freezing winters, providing a layer of mulch around the base of the young tree can offer insulation. Be careful to keep the mulch a few inches away from the trunk to prevent moisture buildup and potential rot.