Many plants can be propagated by cuttings. At the end of summer, it is especially the shrubs and the woody plants for which the period is the most favourable. Unlike herbaceous plants, woody plants are those that begin to take the consistency of wood. And if some herbaceous plants remain so, others become lignified during the month of August, that is why it is common to speak also of Augusted branches for lignification.
When to cut shrubs and woody plants?
The cutting of partially lignified buds is done during the active period, that is from July to September, but the most favorable time starts with the second half of August when the plants have a semi-arched wood, and ends on September 15 approximately.
Ideally, take the stems of cuttings early in the morning when the tissues of the plants are still filled with water.
Semi-sprouted cuttings: for which shrubs and woody plants?
Semi-sprouted cuttings are for geranium, cedar, cypress, privet and a number of other shrubs such as wig tree, azalea, bougainvillea, berberis, bignone, camellia, honeysuckle, chrysanthemum, rockrose, clematis, laburnum, fuchsia, fusain, juniper, broom, hibiscus, hydrangea, holly, winter jasmine, laurel, lavender, lilac, mahonia, St. John’s wort, carnation, passion flower, perovskia, photinia, pittosporum, poinsettia, pyracantha, rosemary, santolin, sage, willow, seringat, skimmia, spirea, elder, speedwell, viburnum, Virginia creeper, weigelia…
How to make semi-hardened cuttings ?
With a sharp and well-cleaned pruning shears, cut young shoots that are hardening into a woody texture: they can be spotted by their hard, brown base and their still tender green tip. These stiff terminal shoots should be 15 to 20 cm long and cut 5 mm below a leaf or bud because this is where the hormones that stimulate root production are concentrated.
Eliminate the tender end as well as some leaves at the bottom, cut the ends of the 2 or 3 leaves remaining at the bottom to shorten them in order to limit water loss by transpiration.
Soak the base in a natural budding hormone such as willow water and plant the stripped part in a substrate composed of equal parts of sand and peat. Potting soil is not suitable, as it may hasten the rotting of the cuttings before they take. Because they will need time…
Place the cuttings under a closed protection which maintains a high hygrometric degree, at a heat of 18 to 24°C in full light but not in full sun: unheated mini-greenhouse, bell, cut bottle of mineral water, plastic bag… Take care that no part of the plant is in contact with the wall of the protection which is too wet and which could make the stem rot.
Aerate regularly to avoid the development of rots due to the confinement.
Generally, it will be necessary to wait for the winter to pass for roots to form. From then on, it is advisable to aerate more and more frequently in order to “wean” the plant and make it ready to face the spring air.
When the buds swell and new leaves are born, spring is here, it is finally time to transplant or repot the cutting that is taken.