Hydrangea shrubs can be propagated using vegetative propagation, a technique that creates genetically identical copies, or clones, of the parent plant. The approach popularized by television gardener Monty Don focuses on using semi-ripe wood cuttings. This material balances the soft, fast-rooting material of early summer with the hard, slower-to-root wood of late autumn, maximizing success rates for home enthusiasts.
Optimal Timing and Material Selection
The preferred material is the semi-ripe cutting, best taken from late summer through early autumn, typically August to mid-September. This timing ensures the current season’s growth has hardened at the base while the tip remains soft and biologically active. This phase provides a favorable balance of stored carbohydrates and rooting hormones to initiate new root growth. Select strong, healthy, non-flowering shoots, as these allow the plant’s energy to focus on root development rather than reproductive efforts. Taking cuttings early in the morning is beneficial, as the fully hydrated plant reduces the risk of wilting before planting.
Executing the Cutting: The Monty Don Method
The initial step requires the use of sharp, clean tools, such as secateurs or a knife, to ensure a smooth cut that minimizes damage to the plant tissue. Once a suitable non-flowering stem is removed, immediately place it into a plastic bag to lock in moisture and prevent desiccation. The cutting material is then prepared by stripping away all the lower leaves and any side shoots, leaving only a small amount of foliage—an inch or less—at the very top of the stem. This reduction in leaf surface area limits the amount of water lost through transpiration, as the cutting does not yet have roots to absorb water.
A clean, precise cut is then made just below a leaf node, the point where a leaf joins the stem. This location is biologically important because it is an area of concentrated cellular activity and a higher presence of natural growth hormones, making it the most likely spot for new roots to emerge. Dipping the prepared base of the cutting into a powdered or gel rooting hormone can increase the chances of successful root formation. The planting medium should be a specialized, gritty mixture, such as compost blended with sharp sand or perlite, which ensures excellent drainage and aeration. Rather than pushing the cutting into the medium, create a small hole first with a dibber or pencil, and gently insert the cutting so the lower node is covered. Finally, firm the medium around the cutting to guarantee optimal contact between the stem and the soil particles before a thorough initial watering.
Nurturing New Plants: Post-Cutting Care
Following the planting, the focus shifts to creating a stable environment that supports the development of new roots. High humidity is achieved by placing the potted cuttings inside a propagator or covering them with a clear plastic bag, creating a miniature greenhouse effect. This enclosed space reduces the rate of water evaporation from the remaining leaves, compensating for the cutting’s lack of a functioning root system. The cuttings should be situated in a location that provides warmth and plenty of light, but they must be shielded from direct, intense sunlight, which can easily scorch the delicate foliage.
After the initial watering, keep the medium consistently moist but never saturated, as waterlogging can lead to the stem rotting. Daily misting of the leaves helps maintain high moisture levels in the air around the foliage. The first sign of success is the emergence of new growth, typically appearing after four to six weeks, indicating the cutting has established a root system. Once the new plant is visibly growing, gently lift and pot it into an individual container filled with fresh, peat-free potting compost. These young plants are best overwintered in a sheltered, cool environment before being planted into the garden the following spring.