Clematis is a highly popular flowering vine, celebrated for its prolific blooms that can transform a garden wall or trellis into a cascade of color. Propagating a favorite clematis at home is an effective and cost-saving way to increase the number of vines in your landscape. Since new plants are clones of the parent, methods like cuttings and layering ensure the offspring will possess the exact flower color and form.
Propagating Clematis Using Stem Cuttings
The most common method for creating numerous new clematis plants is through stem cuttings, taken when the parent plant is actively growing. The ideal time is generally late spring to early summer, utilizing soft, new growth known as softwood cuttings. These cuttings root quickly but require very high humidity to prevent wilting. Semi-hardwood cuttings can be taken in mid-summer from stems that have begun to transition from green to slightly woody.
Select a section of stem that is firm but flexible, avoiding soft tips or overly hard wood. Clematis cuttings are typically taken as internodal sections, cut a few centimeters below a leaf node and above the next node. The leaf node contains the highest concentration of growth hormones where new roots will emerge. Applying a rooting hormone powder to the wounded, lower end of the cutting stimulates cell division and increases the rooting success rate.
To prepare the cutting, remove the lower set of leaves and trim the remaining large leaves in half to reduce water loss through transpiration. Insert the prepared cuttings into a sterile, well-draining rooting medium, such as a mix of sharp sand and compost, or perlite and peat. The environment must maintain near 100% humidity to keep the leaves turgid while roots form, often achieved by placing pots inside a plastic bag or closed propagator. Cuttings root best when kept out of direct sun, receiving bright, indirect light and warmth.
Propagating Clematis Through Layering
Layering is a reliable propagation method because the stem remains attached to the parent plant, continuously receiving water and nutrients until new roots form. This technique is well-suited for home gardeners looking to produce a few new plants. The best time to attempt layering is in the spring or early summer when the vine is in a period of vigorous growth.
Select a long, flexible stem that can be bent down to reach the ground near the base of the plant. At the point that will be buried, gently wound the bark with a sharp knife, making a small slice between two leaf nodes. This injury encourages the stem to produce roots at the site of the cut. To prevent the wound from healing too quickly, insert a small object like a toothpick or pine needle into the slit to keep the cut edges separated.
Treat the wounded section with a rooting hormone and secure it firmly against the soil or into a buried pot of potting mix using a bent wire pin or small rock. Cover the buried section with about an inch of soil, leaving the stem tip exposed and pointing upward. The layered stem must be kept consistently moist for root development, which typically takes six to twelve weeks. Once rooted, allow the new plant to grow attached for one or two full seasons before severing it from the mother plant.
Propagating Clematis By Division
Division is suitable for older, established clematis that have developed multiple stems from the base, though it is not recommended for all varieties. This technique is most practical for herbaceous clematis and robust, hard-pruning Group 3 cultivars. The dividing process is best performed in early spring as the plant emerges from dormancy, or in the fall after the foliage has died back.
Carefully lift the entire root ball from the ground by digging widely around the base to capture the root system. Once lifted, gently tease away excess soil to expose the crown and root mass. The root ball can then be pulled apart or cut into two or three smaller pieces using a sharp spade or knife. Each separated section must possess a healthy amount of roots and at least one viable growth bud for successful establishment.
Essential Care for Newly Propagated Plants
Once clematis cuttings have rooted, they must be gradually acclimated to normal conditions in a process known as hardening off. If rooted in a high-humidity environment, the cover must be slowly removed over one or two weeks to reduce the risk of transplant shock and wilting. Layered plants, which remain attached longer, generally transition easier when separated and potted up.
Rooted cuttings of vigorous species may be ready to plant in their final garden location by the following autumn. However, many large-flowered hybrids benefit from growing in a sheltered pot for a full year. When transplanting, plant large-flowered cultivars with the top of the root ball three to six centimeters below the soil surface. This deep planting encourages multiple stems from below ground, which helps protect the vine from the fungal disease Clematis Wilt.
Newly established plants require consistent moisture, especially during their first full season, to support a strong root system. In early spring, a light application of a potassium-rich fertilizer, such as rose or tomato feed, encourages robust flowering. Applying a thick layer of organic mulch around the base of the vine helps maintain cool, moist soil conditions for the roots.