Kalmia latifolia, commonly known as mountain laurel, is a broadleaf evergreen shrub native to eastern North America with spectacular pink and white clustered flowers. Seed germination is challenging and requires cold-moist stratification for 60 days at 4°C (39°F), followed by light exposure at 24°C (75°F) for germination to occur. Seeds have complex dormancy mechanisms and germination can take up to 12 weeks but typically occurs within 2-6 weeks under optimal conditions.
Before sowing
Cold-moist stratification for 60-84 days at 4°C. Surface sow seeds on moist soil in trays and keep moist during stratification.
Sowing
What to expect
Tips
Seeds require light for germination—place trays with stratified seeds under grow lights or in bright natural light. After stratification, lightly press seeds onto moist acidic soil surface without covering. Maintain soil moisture consistently but avoid waterlogging. Germination temperature should be 24°C (75°F). Living moss can be used as an alternative growing medium. Seedlings emerge slowly and unevenly; patience is essential. Once seedlings develop two true leaves, transplant to individual pots with acidic, humus-rich soil. Keep seedlings in partial shade indoors during first growing season before hardening off.
Sources: Wildflower.org, Sheffield's Seed Company, Gardener's Path, Gardening Know How, University of Georgia HortScience research, USDA Forest Service, Maine Native Plant Trust
