Wollemi Pine cutting propagation

Pruning a Wollemi Pine back by two thirds stimulates many of the epicormic buds that lie dormant beneath the bark. These buds will develop into active shoots. 

Creating a stock plant like this provides you with increased cutting material for propagation. 

Semi-hardwood cuttings are best. These are usually available from March to July in Australia. 

Select stems with healthy growth, free from pests and disease.

Ensure the cutting has at least 3-4 whorls of branch growth. 

The ideal thickness is about the diameter of a pencil.  

Collect cuttings in the early morning, when the plant is fully turgid. 

Use sharp, sterilised secateurs to cleanly cut the stem. 

Cut extra length at this stage to allow for later trimming. 

Mist the cutting and place it in a plastic bag. 

Remember to label all bags if cuttings are from different trees. 

Store cuttings in the fridge if you will not proceed straight away. 

• 70% ethanol or methylated spirits to sterilise your work bench and all your tools. 
• Sharp pruning tools including secateurs, snips and cutting blade. 
• Auxin or "rooting hormone" 5000 - 10 000 parts per million (ppm). Auxin can be in powder (talc base), liquid (alcohol base) or gel form. 
• Decant a small amount of hormone into a clean container; use only as much as you need. Discard that portion after use. 
• Labels and permanent marker. 

• Bucket of 1% bleach solution (10mL per litre) for sterilising plant material. 
• Tongs for handling plant material. 
• Bucket of water for rinsing plant material. 

• Propagation mix. We use 1 part coir peat, 2 parts coarse sand, 4 parts coarse perlite. This mix provides good aeration and enough water retention during root initiation and development. 
• A container 10-12cm deep. 
• A sterile 'dibber' such as a chopstick, to create holes in the mix. 
• A small watering can of Phytophthora- and Pythium-specific fungicide. 

The photo (L) shows the stem after branch pruning. 

5. With secateurs, make a final cut a few millimetres under the node where the lower branches were removed. Nodes are the preferred site for root emergence. 

Any part of the cutting that will be buried below the surface of the mix should be free of branches. 

Note that there is no tip pruning to the branches. Unlike other species, Wollemi Pine cuttings have a better strike rate if the entire branch is retained. 

6. Hold the stem at the apex and use the sharp blade to gently 'wound' the base of the stem. Remove a thin sliver about 1.5cm length. This can be done on either 2 or 4 sides. 

This opens the cambium layer and exposes a greater surface area for callusing, root initiation and promotes greater root mass. 

IMPORTANT: always cut away from yourself, never towards your body. 

7. Dip the cutting into hormone for a few seconds to lightly cover the bottom 2cm of the cutting. 

Our best results have come from a combination of a quick dip in IBA 5000ppm liquid, followed by a dip in IBA 5000ppm powder. 

If using power, gently tap off the excess. 

8. Allow branches to sit for 10 minutes, so the root hormone can be absorbed and begin moving through the plant's vascular system. 

Mist the foliage with a water spray bottle if leaves look dry. 

9. While the hormones are absorbed, prepare holes in the potting mix to a depth of 2-3cm. Make the hole larger than the cutting so rooting hormone powder is not rubbed off when the cutting is placed into the mix. 

Write up labels to include the date, quantity of cuttings, hormone treatment and tree or plant number (if relevant). Record keeping will help you track the time taken for cuttings to strike and calculate your success rate. 

10. Place each cutting, ensuring that the lowest nodes are a few centimetres below the surface. Press the mix around the stem to ensure it is firmly positioned. 

In the nursery, cuttings are kept in a controlled environment glasshouse with heated benches, misting and fogging. 

You can replicate a similar environment at home:

• Keep the pot in a room with indirect light and a temperature between 17 to 27 degrees C. 
• Cover the stems and pot with a snap lock bag or a mini greenhouse and mist the foliage every few days to retain humidity and minimise transpiration. 

Ensure the mix does not dry out; keep it damp but not too wet, or cuttings will rot. 

Over the coming weeks, remove any cuttings that begin to fail. This will prevent fungal spread through the pot. 

In approximately 12-14 weeks, roots will be visible from the base of the pot! 

Separate the cuttings by gently disentangling the roots. Pot them up into individual pots. A forestry tube is an ideal size. 

Do not plant too deeply, as this can lead to collar rot. 

• Use a premium grade general purpose potting mix.
• Ensure the potting mix meets the Australian Standards (look for a logo with five red ticks). The ideal mix will have both good moisture retention and drainage. 
• Wollemi Pines are not phosphorus-sensitive; in fact, they are heavy feeders. So do not use a native plant potting mix. 
• Add a small amount of controlled release fertiliser (a general purpose with trace elements; lasting 8-9 months). 
• Use a bamboo stake to help stabilise the plant whilst it is establishing and developing a larger root system.