Cutting Media needs to be sterilised inert i.e. minimal to zero nutrients in the media. Nutrient inert propagation media is also generally fine for raising seeds.
A cutting mix of equal parts of coco-peat, perlite, and/or sharp washed river sand.
Many commercial nurseries use perlite only as their cutting’s media.
Pour boiling water over the media or microwave the damp cutting media mix to kill any microbial pathogens.
It is important that the propagation mix be as sterile as is possible and is neutral, or inert, ie, free of any nutrients. Commercially packaged cutting propagation mixes are usually not chemically inert, they have added nutrients from which cuttings can draw on, but may slow down or stop the hormonal progression of root development.
Ensure the media is throughly damp, but well-drained of any free water.
Prepare the cuttings
Remove leaves from the the bottom of cuttings. BUT:
Leave 2 to 3 leaves at the top of cuttings.
Reduce the area size of larger leaves. If the leaves have a large surface area or are diseased or damaged, clean cut a cross-section of the leaves with sharp clean secateurs (Felco 310).
Remove apical dominance: Carefully cut any very soft leaves, flowers, or growth and flower buds at the very tip of the cutting (apical buds).
You are removing the cuttings meristem, that is, any undifferentiated stem cells that plant hormones will turn into diffentiated leaf and flower bud tissues.
Prepare your cutting then remove a thin vertical slice or wound the stem bark near the basal end of the cutting.
Note: The area of rooting of cuttings will be increased by wounding the base of the cuttings stem — that is, taking a vertical slice of the bark. This aids side root (lateral root) formation.[3
The length of the vertical wounding of shoot-borne cuttings will depend on the vertical distance between the leaves of the cutting (internode); a rough guide of I – 2.5cm can be applied. This creates a larger surface area between nodes for the formation of lateral or side roots.
Prunings can be cuttings
Dipping in a rooting hormone:
Eg. Rootex Gel Purple for semi-hard cuttings. Eg. Correas, Croweas
Eg. Rootex Gel Red for woody or hardwood cuttings. Eg. Grevilleas, Banksias, Hakeas
Eg. Rootex Gel Green for soft cuttings. Eg. Daisies, hairy Grevilleas
Eg. Rootex Powder for soft and hairy cuttings. Eg. Daisies, hairy Grevilleas eg Grevillea lanigera, Grevillea alpina.
Before dipping, clean-cut a mm or two off the base of the cuttings.
Immediately dip into hormone. One to three seconds approx. Drain any excess dipping hormone.
Place cutting in the punnets. Ensure the dipped cuttings are to a depth that ‘buries’ the wound.
Label the punnets of the cuttings. Note binomial and common name, date etc.
Watering Cuttings:
Do not water the cutting for the first 24 hours as you may wash the hormone away from the cuttings.
Ensure the cuttings are, at all times, in a humid environment eg place a clear plastic bag over the cuttings.
Or create a cuttings or propagation box using tote boxes with several 1 mm holes drilled around the base and the lid. Place a layer of washed gravel in the base.
Rooting of the Cuttings:
Over time a callus forms as a result of the wounding of the cutting and the rooting hormone to the cambium.
Callusing can be imperceptive or oblivious to the eye or the callus maybe thick and wart-like. Thick callusing may inhibit or stop root formation. Such cuttings need to have their thick callus removed redipped and returned to the propagation punnet.
Roots emerge from around the nodes, as well as the wound’s callused vertical slice of the bark (lateral roots) and the basal healing callus.
Roots will emerge over time ie weeks, a month, or months and is subject to temperature and type of plant. Woody cuttings will take longer than softer and semi-hard cuttings.
From time to time, water punnets with a very weak solution of Seasol.
When the roots appear through the drainage holes: drench with a very weak solution of Seasol, drain and carefully tease the rootball apart and pot up and grow each rooted cutting in its own tube or pot.
Use low phosphate/native potting up mix, plus, for drainage, one in ten by volume (approximately) well washed sharp river sand (not brickies sand).
Place pots in a shady place and keep moist, but not wet. Do not over water.
Feel free to ring or email me should you need any advice on propagating native plants.
Bill Willis
Horticulturalist/ Grower, Queanbeyan Landcare, FOG, ANPC, ANPSC, Hort. Society member.
