Prepare a rooting ditch for the redstem dogwood cuttings in summer around late May or early June before the shrubs bloom. Choose a site with good drainage and partial sun during most of the day.
Dig a 12- to 16-inch-deep furrow using a mattock. Make the rooting ditch long enough to provide 6 inches of space on either side of each cutting. Fill the ditch to the top with coarse horticultural sand. Run water over the sand using a garden hose until it is completely saturated.
Gather redstem dogwood cuttings during the cool morning hours to minimize stress on the mother plant. Select healthy side shoots with young growth at the tip and older, two-year-old growth at the base. Avoid cuttings with buds or active flowers.
Measure 15 to 30 inches down from the tip of the branch. Cut the branch at a slight angle using a pair of sharp anvil shears. Strip off all the leaves from the bottom half of the redstem dogwood cuttings.
Scrape the base of each redstem dogwood cutting using the sharp blade of the anvil shears. Remove a portion of bark measuring 1 to 2 inches in length and 1/4-inch in width. Scrape only enough bark off to expose the pale green inner cambium, which contains a high concentration of growth cells for root production.
Apply a thin layer of 0.2-percent IBA rooting hormone powder along the lower half of the redstem dogwood cuttings. Use a paintbrush or old rag to coat the cutting in rooting hormone.
Insert the redstem dogwood cuttings into the rooting ditch to half their height. Space the cuttings 6 inches apart to provide enough room for root production. Push the coarse horticultural sand in around the cuttings to hold them upright.
Water the redstem dogwood cuttings every three days for the first month or two after striking them. Apply only enough water to keep the top 2 inches of sand moderately moist at all times.
Transplant the rooted redstem dogwood cuttings in late summer around early September. Carefully excavate around each cutting by hand and lift them from the rooting ditch. Move them into 1-gallon nursery containers filled with garden soil or plant them directly into the ground in climates where the first frost falls later than October 20.
Keep the newly transplanted cuttings protected during their first winter. Spread a 3-inch-thick layer of mulch around the base of redstem dogwood cuttings that are planted directly in the garden. Move container-planted cuttings into a cold frame or unheated greenhouse until the weather warms to 68 degrees F in spring.