Marrubium vulgare, commonly known as white horehound, is a hardy perennial herb in the mint family native to Mediterranean and Asian regions. Seeds exhibit slow and erratic germination requiring patience and consistent moisture; cold stratification for 30 days significantly improves germination rates. This medicinal herb has been valued for centuries in treating coughs and respiratory ailments.
Before sowing
Cold stratification for 30 days improves germination by 35-40% and can enhance optimal temperature germination by up to 70%
Sowing
What to expect
Tips
Use small pots or plug trays to remove germinated seedlings without disturbing ungerminated seeds. Keep soil consistently moist but not waterlogged during germination. Cold stratification in refrigerator for 30 days substantially improves germination rate. Sow seeds shallowly (1/8 to 1/4 inch deep) on soil surface or with light soil covering. Maintain temperature around 68-75°F for optimal results. Seeds germinate better under alternating light/dark cycles. Surface-sown seeds show 87% germination compared to buried seeds. Once established, seedlings are extremely drought-tolerant.
Sources: Research gates, Floral Encounters, Outside Pride, PFAF, Weed Science journal, Javaid et al. 2018, Wikipedia, Baker Creek Seeds, Utah State University Extension, Gardening Know How
