Lavandula dentata var. dentata 'Royal Crown' is an RHS Award of Garden Merit-winning evergreen subshrub native to the Mediterranean basin with distinctive toothed gray-green leaves and long-stalked spikes of purple flowers topped with pale violet bracts. French lavender seeds require cold stratification and light to germinate; they are notoriously slow and may take 1-3 months to sprout, making patience essential during the germination process.
Before sowing
Cold stratification strongly recommended for improved germination rates. Place seeds in moist medium in refrigerator for 3-6 weeks at 35-40°F (1-4°C) before sowing.
Sowing
What to expect
Tips
Surface-sow seeds and press lightly into soil but do not cover deeply—seeds need light to germinate. Maintain warm temperatures of 65-75°F (18-24°C) with a heat mat if necessary. Keep soil moist but never waterlogged using mist spray bottle. Provide bright, indirect light to avoid drying the medium too quickly. Use a humidity dome initially, but remove daily to prevent fungal diseases and ensure good air circulation. Germination is slow and uneven; seeds may take 14 days to 3 months to sprout. Once seedlings emerge, reduce humidity and ensure strong light from grow lights (12-16 hours daily). Transplant to larger pots when seedlings reach twice the height of the tray. This cultivar is tender and best started indoors 10-12 weeks before last frost date.
Sources: Royal Horticultural Society (RHS), Seeds and Plants (South Africa), The Seed Vine Australia, Island Lavender, Terra Mater Gardens, Bright Lane Gardens, Cultivated Earth, Wikipedia, Kew Science
