Growing Pawpaw (Asimina Triloba) From Seed
The process of selecting and breeding superior pawpaws has only just begun, so if you can get seed from a good parent tree, its worthwhile to grow out the seedling to fruiting age. Growing pawpaws from seed is also the best way to produce rootstock for grafting known cultivars.
To break dormancy, pawpaw seeds require a period of moist, cool stratification. Seeds directly sown in the fall will receive this over the winter and generally germinate the following summer. Chipmunks an affinity for disturbing pawpaw seeds sown in ground. A protective wire screen over the seedling bed may help mitigate this issue.
Seeds can be stratified in a refrigerator over the winter and sown indoors in the early spring. Refrigerated (32°-40° F) seeds should be stored in a zip-lock bag with a bit of damp medium like peat moss or coconut coir. 70-100 days is the recommended stratification period.
The seed should be sown 1'' deep in a light, well drained soil mix, pH 5.5-7. Germination will occur readily at a temperature between 75°-85° F . Sow seeds in tall containers, with a height of about 10” designed for tap rooted seedlings. The seed will normally germinate in 2-3 weeks, and the shoot will emerge in 2 weeks to 2 months.
Stratified seeds can also be wrapped in piece of damp paper towel and placed in a zip-lock bag. Place this bag in warm location (75o- 85o F), out of direct sunlight. Once the tap root radical emerges, the sprouted seed be planted in a pot as described above.
Provide seedlings with dappled sunlight, full sun will scorch the leaves of 1st year seedlings. With proper care, seed grown pawpaw's will fruit in 5-8 years. Two genetically distinct trees are needed for fruit set.