The paw paw tree (Asimina triloba) is a fruit-producing tree indigenous to North America. It is a relatively small-growing tree, usually reaching heights of between 20 and 25 feet. Paw paw trees produce large, edible fruit that resemble a mango in shape and have a banana-mango flavor. Germinating paw paw trees from seed requires a period of moist, cold storage in order to break the dormancy of the seeds.
Preparing Paw Paw Seeds
Cut open a soft, ripe paw paw fruit to remove the paw paw seeds from the pulp. Set the paw paw seeds into a colander or wire basket. Rinse the paw paw seeds under cool tap water. Use a small brush, if necessary, to remove excess pulp from the seeds.
Place approximately 1 cup of moistened sphagnum moss into a sealable zipper-top plastic bag.
Place the paw paw seeds into the plastic bag containing the sphagnum peat moss and seal the bag closed.
Place the bag containing the paw paw seeds into a refrigerator where the temperature is approximately 30 to 40 degrees Fahrenheit. Leave the bag in the refrigerator for approximately 90 days. Check on the contents of the bag at least once a week to make certain the sphagnum peat moss remains moist. Mist the sphagnum peat moss with water to keep it moist to the touch.
Remove the paw paw seeds from the sphagnum peat moss after the allotted time has passed and pot them.
Planting Paw Paw Seeds
Pour or scoop potting mix into individual planting containers until each is filled with soil. Kentucky State University suggests using tree pots for planting paw paw seeds. Tree pots are deep growing containers (between 14 and 18 inches tall) used especially for trees with long tap-roots, such as the paw paw tree.
Poke a 1-inch deep hole in the center of each of the planting containers. To accommodate the large paw paw seed, each hole should between 1/2 and 3/4 of an inch wide.
Plant one paw paw seed into each of the 1-inch-deep holes.
Scoop approximately 1 inch of potting mix over each of the paw paw seeds. Then gently tamp the soil down in each of the planting containers.
Transfer each of the planting containers to a sheltered (out of direct sunlight) location that is between 75 and 85 degrees Fahrenheit. Provide about eight to 10 hours of filtered light every day. Keep the soil in the planting containers moist, but never soggy. Germination of paw paw seeds can begin in as little as two to three weeks, or can require as long as seven weeks.
Water the paw paw seedlings often enough to keep the soil in the containers moist. The paw paw seedlings must be kept in a sheltered, shaded location for the first two years after germination, according to Kentucky State University.