Bolusanthus speciosus, commonly known as Tree Wisteria, is a spectacular deciduous tree native to southern Africa, renowned for its striking drooping clusters of violet-blue, fragrant pea-like flowers. Seeds possess a hard waxy coat requiring hot water scarification before sowing, and germination occurs quickly under warm conditions with good light exposure. Seedlings are ready for transplanting once the second leaf emerges.
Before sowing
Soak seeds in hot water overnight. The hard outer seed coat is impervious to water and scarification is essential for successful germination
Sowing
What to expect
Tips
Sow seeds lightly covered or just under the surface of moist substrate; avoid burying too deeply. Keep substrate consistently moist but not waterlogged. Provide warm conditions (18-22°C optimal) with bright, indirect light or full sun exposure. Transplant seedlings when 12 cm tall or after second leaf emergence into a soil mixture of equal parts sand, loam, and compost. Seeds may remain dormant if conditions are unfavorable; do not discard apparently failed seeds immediately as they may germinate after extended waiting periods.
Sources: PlantZAfrica, Useful Tropical Plants Database, Australian Seed, Plant Resources of Tropical Africa (PROTA), Top Tropicals Plant Encyclopedia
