Wollemi Pine seeds exhibit non-deep physiological dormancy, which can be relaxed by cold stratification for several weeks at less than 10°C (Offord and Meagher 2001). These conditions are believed to mimic the fall of ripe seeds in late summer, their exposure to moist cold conditions in winter and germination in spring and summer (Offord and Meagher 2001).
- Cold stratification (storage of seed for 2 weeks in your fridge) is beneficial to the germination rate and encourages a more uniform germination period.
- After 2 weeks in the fridge, bring the seed out and leave overnight to return to room temperature.
- Use a premium grade seed mix that is certified to meet the Australian Standards.
- Choose a punnet or tray for sowing seeds:
- A multi cell seedling punnet enables you to sow individual seeds in each cell and provide enough depth to let it grow on for at least six months.
- Alternatively, a seedling tray means sowing all the seed together and then pricking them out individually when they are large enough to pot up. These shallow trays run the risk of misshaping the radicles and primary roots, as well as overcrowding; which leads to leggy growth.
- Press your finger into the seed mix to make an indentation of 5mm.
- Place the seed in laying sideways.
- Gently cover the hole over with mix and water in well.
- Do not allow the mix to dry out; keep moist but not soggy. It may just need a daily misting.
Optimal Environment for seed germination
- Temperature range between 24-30°C
- High humidity and high light
- The home gardener can achieve this with the use of mini-greenhouses and heat mats.
- In the absence of these, try placing the multi cell punnet in a clear plastic tub in a well-lit and warm room.
- Open the vents to allow air flow once germination commences.
- Germination will commence 20-30 days after sowing with a period of rapid germination until 40-60 days, with germination then slowing again.