Pawpaw trees are deciduous plants native to North America. They tend to grow at the lowest level of a forest, under the canopy, and form thick woven patches that can act as ground cover in the wild. A fruit can be harvested from the pawpaw tree that is edible and has the same appearance as a papaya, although the flavor is more like a banana mixed with a peach. The trees are notoriously hard to pollinate, because normal pollinators do not visit the flowers. Home gardeners take an interest in pawpaw trees because they are low maintenance and naturally resistant to most diseases.
The pawpaw tree is a member of the species Asimina triloba, part of the Annonaceae family. It is the only member of the family that grows outside of tropical climates. Even though pawpaw trees often act as ground cover, they grow to an average size of 10 to 30 feet (3 to 9 meters). The tree has long, dark green hanging leaves. These trees naturally grow beneath the forest canopy, so they require only partial sun to grow and have difficulty tolerating full sun.
The flowers of the pawpaw tree are pinkish-red, hang upside down and measure approximately 2 inches (5 centimeters) in diameter. They have a distinctly unpleasant odor and are considered a carrion flower because of the smell. The attributes of the flower deter normal pollinators from helping in reproduction. This has led to the observation that pawpaw trees are pollinated primarily by carrion insects such as beetles and blowflies.
Even though pawpaw trees have both male and female parts within the same tree, they are not able to self-pollinate. They must be pollinated from a separate tree. In home gardens, because normal pollinators will not perform the task, pawpaw trees can be pollinated by hand with a brush.
The bark of pawpaw trees contains acetogenin, a substance studied for its cancer-fighting properties. The fruit of the tree is edible and contains a high amount of protein. It has been eaten as a food for hundreds of years in North America. In some parts of the United States, the fruit is harvested and baked into cakes or pies. The pawpaw fruit has not seen widespread distribution, however, because it begins to perish immediately after being removed from the tree.
Growing pawpaw trees is very easy compared to some other trees. They are naturally resistant to many diseases and repel a number of insects. The fruit is edible but must be eaten immediately after it becomes ripe. As a ground cover, the tree is robust and grows readily in partial shade. The tree requires a dormant period of 90 to 120 days in winter temperatures.