Rhododendrons, including azaleas, can be propagated by cutting off pieces of the bush's stems and rooting them. This process requires a good deal of patience, because unlike tender green plants that root quickly, the woody stems of rhododendrons may take months to produce roots. Take trimmings from healthy plants only. If your rhododendron has been grafted to rootstock, be sure to take a cutting from as close to the top of the bush as possible because the bottom may produce flowers that are much different than the ones you're accustomed to.
Sanitise your pruning shears and razor blade in the bleach solution by dipping each in for 10 seconds and allowing them to dry.
Identify the new growth on the rhododendron as this is what will be used to propagate the plant. The new growth will appear different than the established wood. It will be lighter in colour, have thinner stems and be more pliable when bent.
Cut stems with the pruning shears that are at least 1 inch long, according to the Middle Atlantic Chapter of the American Rhododendron Society. Vertically growing stems are ideal as they will grow in that direction when potted.
Sanitise the cuttings by dipping them in the bleach solution for 10 seconds each. Do not rinse.
Dip each cutting in the anti-fungal solution mixed to the container's specifications.
Use the razor blade to gently remove any flower buds from the stems. Cut each remaining leaf in half with the razor blade to minimise water loss through the leaves. You can skip this step if your rhododendron has very small leaves. However, pluck off any excess of leaves, leaving just four to six at the top of the cutting.
Chip or scar the stem to make it more tolerant for rooting by taking a small diagonal wedge off the bottom. The Middle Atlantic Chapter of the American Rhododendron Society states that this should be removed from the bottom 1 to 1 1/2 inches for longer stems.
Dip the very bottom of each stem into the rooting hormone mixed to the container's specifications. The notch you made with the razor blade should be covered. Tap off any excessive powder.
Plant the stems in a well-drained medium.
- Wear plastic gloves when handling the bleach, fungicide and rooting hormone to prevent damage to the skin on your hands.
- Transfer the cuttings to the planting medium within one to two weeks after collection for best results.