Semi Ripe cuttings
Semi-ripe cuttings are taken from the current season’s growth, where the stem has started to thicken and is becoming slightly tough. They are usually taken in late summer, early autumn when the plants growth has started to slow. Generally deciduous plants (those that lose their leaves in winter) such as Weigela, Cornus and Philadelphus, but some evergreens, lavender, ivies and choysia also strike well.
Start by selecting clean healthy shoots that are free from any visible pests or diseases. Also make sure the shoots you are selecting are true to type, in the instance of many variegated hebe’s, choysia’s, euonymus etc, the plants will often revert back to their natural plain green form, any cuttings taken from these shoots will produce plants in their plain form.
Remove shoots with small internodes at about 4 – 6” (10 – 15cm) long, cutting just below a leaf node, remove the lower leaves and the main growing tip. On larger leaved plants, it is often worth cutting the leaves in half to minimise water loss. Dip cutting in hormone rooting powder, maxicrop take root, or similar and insert into cuttings into individual pots, not bigger than 3” diameter filled with a decent cutting compost:
Cutting compost mix:
Beginners mix: 2 parts multi purpose compost with 1 part sand
Intermediate mix: 30 litre peat/ peat based compost
10 litre silver sand
2 litre perlite
2 litre vermiculite
1 handful super phosphate
Put the pots of cuttings, ideally into a propagator with bottom heat, or into a greenhouse or on a windowsill, keep moist but allow them to dry out periodically to encourage healthy root development, remove and dead or diseased leaves as soon as they become apparent and check regularly for roots showing through the bottom of the pot. When roots are visible, repot into a slightly larger pot, or plant out directly into the garden.
Note: some semi-ripe cutting can have as little as a 25% success rate, so always strike a few more than you need.
Stool Layering – useful if a plant has become overgrown and woody, simply dig the plant up and burry it slightly deeper, after 12 months has passed, dig the plant up again and split, the woody growth that was originally above ground level should now have rooted and will produce a plant in its own right.
Simple layering – select a healthy shoot free from visible pests and diseases, lightly scrape away a thin layer of the stems outer bark to assist root development, brush with maxicrop take root or hormone rooting powder and carefully bend the shoot towards the ground and peg down to keep the exposed area in contact with soil, lift in 12 – 18 months time when the layered shoot has produced its own root system and cut away from main plant. Alternatively, fill a small pot with cutting compost and sink this into the ground, follow the above instructions but insert the exposed area in the pot of compost, this often makes rooting slightly quicker.
Air layering: (mainly houseplants inc. ficus robusta, various succulents and some cacti)
Bark strip removed layering: used for ficus: cut a ring around the stem, approx 1/18th” deep just below a leaf , do the same approx 1” lower, remove the strip of bark between the two rings with a sharp knife. Tightly wire some moist sphagnum moss around the entire wound and wrap in plastic, keeping as air tight as possible to reduce the risk of infection, within 12 – 16 weeks, the moss should be filled with roots, cut the new plant away and pot up separately.
Open slit air layering: cut a slit at an upward angle approx 1/3 through the stem of the plant, insert a piece of heavy gauge wire, toothpick or similar onto the slit to keep it open and continue to moss and wrap as above.
Some plants such as strawberries are self layering and produce many “runners”; these can also be treated as layering by pegging or pegging into post, which will speed up the rooting process.