Catharanthus roseus (Madagascar Periwinkle) is an evergreen tender perennial native to Madagascar, commonly grown as an annual ornamental. Seeds are very easy and fast to germinate, requiring warm temperatures and darkness to sprout.
Before sowing
No pre-treatment needed — sow directly.
Seeds do not require pretreatment; no scarification, stratification, or soaking needed
Sowing
What to expect
Tips
Surface sow seeds 2mm deep; keep soil moist but not waterlogged; cover tray with plastic bag or vermiculite to maintain darkness; high humidity (100%) and warmth (77°F/25°C) accelerate germination; reduce humidity to 40% after cotyledon emergence; seeds remain viable 3-5 years
Sources: Sheffield Seed Company, PFAF Plant Database, PT Horticulture, The Seed Collection Australia, UF/IFAS Extension, North Carolina State Extension, Gardening Know How
