Leucadendron strobilinum, commonly known as Peninsula conebush, is a dioecious shrub endemic to the Cape Peninsula of South Africa and valued for its distinctive cone-shaped seed heads and attractive dark green leaves with red tips. Seeds are serotinous with winged achenes and germinate readily to 100% in appropriate conditions, typically within 3-4 weeks when given proper temperature cycling, moisture, and smoke pre-treatment.
Before sowing
Pre-treatment with smoke or warm water highly recommended. Smoke treatment is beneficial in reducing germination time and increasing germination percentage in Proteaceae family members.
Sowing
What to expect
Tips
Sow seeds in autumn when day-night temperature difference is around 12°C or in spring with daytime above 22°C and night below 10°C. Keep seeds moist but not waterlogged to prevent rot. Sterilize growing medium to prevent fungal infections. Do NOT use fertilizers containing phosphorus. Protect seed trays from mice, birds, and squirrels with shade netting. Transplant seedlings into individual containers once first true leaves appear. Keep in semi-shade and avoid direct sunlight during germination.
Sources: PlantZAfrica (Kirstenbosch National Botanical Garden), Silverhill Seeds, Australian Seed Supplier, Research on fire-mediated germination syndromes in Leucadendron (Oecologia 2021)
