Asimina triloba, the pawpaw, is a temperate deciduous tree native to eastern North America and the northernmost member of the tropical Annonaceae family. Seeds exhibit physiological dormancy and display moderate recalcitrance, requiring 90-120 days of moist, cold stratification at 0-4°C followed by warm, moist conditions for germination. Radicle emergence can occur within 18 days of warm stratification, but epicotyl (shoot) emergence typically requires 6-8 weeks.
Before sowing
Seeds exhibit moderate recalcitrance and must remain moist throughout storage and stratification. Desiccation rapidly reduces viability; seeds lose 50% viability when dried from 37% to 25% moisture content. Store moist seeds in sealed plastic bags with damp sphagnum moss, peat moss, or sand at 0-4°C. Never allow seeds to freeze or dry out, as this damages the dormant embryo. If seeds dry for 3 days at room temperature, germination can drop below 20%.
Sowing
What to expect
Tips
Use fresh seeds extracted from fully ripe fruits for optimal germination. Never allow seeds to dry out—keep them moist in sealed plastic bags with sphagnum moss, peat moss, or sand at 32-40°F (0-4°C) for 90-100 days. After cold stratification, soak seeds in warm water for 24 hours before planting. Sow seeds 1 inch deep in well-drained soil at 75-85°F (24-29°C) in tall containers to accommodate the long taproot. Germination is hypogeal (root develops before shoot emerges), so expect minimal above-ground activity for 2-3 months. Seedlings are sensitive to direct sunlight and require dappled or partial shade during the first year. Maintain soil consistently moist but avoid waterlogging. Protect outdoor seedlings from direct afternoon sun and harsh conditions. Temperatures of 29-32°C (optimum) hasten emergence by 10 days compared to 24-29°C.
Sources: University of Kentucky (Finneseth et al., 1998), USDA ARS National Clonal Germplasm Repository, Alabama Cooperative Extension System, Kentucky State University, and peer-reviewed research on pawpaw propagation
