Note: Pawpaw Trees have a strong taproot and do not always do well when transplanted as a bare root plants. Because of this we grow ours in deep pots and ship in the pots to make transplanting highly successful.
Plant Pawpaw Trees for Zebra Swallowtail Butterflies!
Pawpaw Tree (Asimina Triloba) is also known as Indiana Banana, American Custard Apple, Banango, Poor Man’s Banana, or Hoosier Banana. It is the only plant on which the larvae of the Zebra Swallowtail Butterflies will feed.
Pawpaw Tree Characteristics
Asimina Triloba is native to the temperate woodlands of the eastern USA. The American Indians are credited with spreading it across the eastern U.S. to eastern Kansas and Texas, and from the Great Lakes almost to the Gulf. It is indigenous to the U.S. Pawpaw trees have been grown successfully in parts of California and the Pacific Northwest.
Pawpaw tree is hardy in USDA zone 4-8. It is a deciduous, often narrowly conical, slow growing tree (especially when it is in the younger stage). At maturity, it will reach 12-20 ft. tall.
The flowers which are produced from about March to May are about 2 inches across, maroon, and grow “upside-down”. Each flower is capable of producing several fruits but pollination can be difficult. Assisting with pollination will help with fruit production.
Two trees are required for pollination (ours are grown from seed so they will cross-pollinate), however, the fruits are not utilized by the Zebra Swallowtail caterpillars/butterflies so you will only need multiple specimens if you would like to produce fruit and seed.
Our Asimina triloba is not grafted. We sell the native species primarily for the butterflies.
Asimina Triloba for Zebra Swallowtail Butterflies
The leaves of the pawpaw tree contain highly toxic acetogenins, which repels most varmints except a leaf roller caterpillar and the Zebra Swallowtail caterpillar. These are benefiting from this toxicity by becoming inedible to their potential predators.
The Zebra Swallowtail caterpillars feed exclusively on young pawpaw foliage, mostly at night. They lay individual light green eggs usually on the underside of the leaves. The adult butterflies will put on their beautiful shows in mid-spring and again in July. They use the nectar of plants such as milkweed, zinnia, lantana, tithonia, dogbane, redbud, and blackberry.
As a result of the pawpaw trees being its only food source, the Zebra Swallowtail butterfly range is nearly the same as the native range of Asimina Triloba.
Asimina Triloba Growth Conditions
The very young specimens have to be kept away from full sunlight for the first year or two. It is ideal for them to receive full day of filtered sunlight during this period. Afterwards, they prefer full sun.
Pawpaws prefer moist, fertile, and slightly acidic soil. Adding compost to the soil will help improve their chances to grow in the Western US. They do not tolerate heavy, wet, alkaline soil.
Propagating Pawpaw Tree, Seed or Cuttings
Pawpaw seeds should never be allowed to dry out after collecting.
The seed must be cold stratified (in a closed up zip-lock bag containing a small amount of damp sphagnum moss) for 90-120 days at 32-40°F. When started in a greenhouse, germination should occur in about 7 weeks. If the seeds are field planted during autumn, they will come up around July or August the following year.
Young pawpaw trees’ roots are very fragile, therefore the seedlings should be moved with the roots and the soil undisturbed (plants started in pots make the best candidates). They also require good drainage and regular watering during the first year.
Asimina Triloba may be propagated from softwood cuttings if extra steps are taken (such as providing irregular misting, bottom heat of about 80°F and 14hrs. of light per day).
Grafting should be done in the spring (after the emerging of new growth). All grafting and budding methods should work with the exception of T-budding.
Why Buy Pawpaw Trees
Asimina Triloba is fairly small, with a tropical look to it. Its foliage can be very attractive during autumn when it turns a brilliant yellow. Once established, it is a low maintenance tree, resistant to disease and critters (unappetizing to deer, rabbits, goats, etc., though foxes, opossums, squirrels, and raccoons will eat the fruits).
The Zebra Swallowtail caterpillars and butterflies are interesting and beautiful and this tree is the only invitation to bring them in your garden!