Passiflora caerulea, commonly known as blue passion flower, is a frost-hardy climbing vine native to South America that produces intricate blue and white flowers and orange egg-shaped fruits. Seeds have a tough coating that benefits from warm soaking and light scarification to improve germination rates. Germination is slow and erratic, typically occurring between 1-12 months at cool temperatures (around 20°C).
Before sowing
Avoid chemical scarification with acids such as hydrochloric acid, which inhibits germination. Combine soaking and light mechanical scarification for best results.
Sowing
What to expect
Tips
Sow seeds in late winter or early spring in a greenhouse. Maintain warm soil temperature of 70-85°F (21-29°C) for best results; cooler temperatures significantly delay germination. Place seeds on soil surface or just beneath (not buried) and cover container with clear plastic to retain moisture. Provide light once sprouted. Keep soil consistently moist but not waterlogged. Avoid high humidity combined with poor air circulation to prevent fungal issues. Seedlings should be kept in a greenhouse for their first winter before transplanting outside after the last frost. Mulch roots in fall to protect from cold in temperate climates.
Sources: Sow Right Seeds, MasterClass, Sheffield's Seed Co., Tradewinds Fruit, Mendiondo & Amela García (2009, 2006)
