Eucalyptus radiata subsp. radiata is a narrow-leaved peppermint tree endemic to cooler and wetter forest regions of south-eastern Australia. Many Eucalyptus species benefit significantly from cold stratification, which mimics winter conditions and enhances germination success. This subspecies shows improved germination rates and vigor when seeds undergo 4 weeks of moist cold stratification.
Before sowing
Place seeds on moist substrate (without waterlogging) for 4 weeks in a moist environment using paper towel, moist sand, perlite, or vermiculite in a sealed plastic bag. Alternatively, cold stratify at 4°C for 4 weeks before sowing.
Sowing
What to expect
Tips
Surface-sow seeds onto moist substrate after stratification and cover lightly with fine sand to reduce damping-off risk. Maintain consistent moisture without waterlogging. Provide bright light immediately after germination. Transplant seedlings when the first pair of true leaves is fully expanded. Seedlings typically reach transplant size in 8-10 weeks and are ready for field planting 12-14 weeks after sowing. Keep seedlings growing vigorously to avoid pot-bound plants. For seed viability, verify through tetrazolium testing if large-scale propagation is planned.
Sources: Springer Nature Link (2021), Australian Wildflower Seeds, Trees and Shrubs Online, Useful Temperate Plants Database, Wikipedia, VicFlora, Australian Plants Society
