Abies grandis, commonly known as Grand Fir or Giant Fir, is one of the tallest true firs native to the Pacific Northwest of North America. Seeds require cold moist stratification to break physiological dormancy, with germination typically occurring 3-8 weeks after sowing stratified seeds. While naturally challenging, seeds can be successfully germinated with proper pre-treatment and careful moisture management.
Before sowing
Cold moist stratification is essential for breaking dormancy. Seeds can germinate in cold stratification; check regularly and sow when approximately 10% of seeds show chitting. Alternatively, some seedlots may require no pretreatment for satisfactory germination.
Sowing
What to expect
Tips
Soak seeds in room temperature water for 24 hours, then place in moist medium (peat moss, vermiculite, or sand) at 0-4°C for 6-8 weeks. Check regularly as seeds may begin germinating during stratification; sow when approximately 10% of seeds show chitting (radicle emergence). Sow stratified seeds at 0.5 cm depth, firm soil gently, cover lightly with vermiculite, and tamp soil. Mulch seed bed and maintain medium moisture. Keep seedlings in warm conditions (15-25°C) after sowing. Seedlings are prone to damping off fungus; ensure good drainage and air circulation. Germination is light-indifferent but seedlings grow best with adequate light once emerged.
Sources: Portland State University Seed Bank, University of Washington Propagation, Sheffield Seeds, Trees Seed Online, PFAF, Calscape, Forest Research UK, Native Plants Network
