Pawpaws

Most of us are unfamiliar with pawpaws. Even my computer didn’t recognize the word. This is a shame because pawpaws (Asimina triloba) are North America’s biggest edible tree fruits. We don’t see them in stores because they bruise easily and start fermenting as soon as they ripen.

Pawpaw fruit and leaves (Scott Bauer, USDA) Public Domain

Tagged with a variety of common names such as Indian custard, Hoosier banana, custard apple, and Quaker delight, the word pawpaw is believed to be from the Spanish word for papaya. They are said to taste like a combination of banana, citrus, mango, and pineapple, with a consistency similar to Hachiya persimmon. These North American natives are commonly found from the Great Lakes region south to the Florida panhandle. More often than not, pawpaw trees are completely overlooked, their bounty left for bears, gray foxes, and other wildlife.

I think that it’s time we all knew a little more about these cousins of cherimoya.

Pawpaw tree description

Pawpaws are large shrubs or deciduous trees that can reach 35 feet in height but are commonly much smaller. They tend to form thin-trunked colonies in shady bottomlands, but will not thrive in full shade. They spread using root suckers. Seed reproduction only rarely results in viable trees in the wild. They have large, simple leaves that grow in clusters at the ends of branches. When bruised, the leaves are said to smell similar to green bell peppers.

Pawpaw flowers are reddish-purple and can be 2” across. Because these flowers smell more like carrion than fruit, blowflies and carrion beetles do most of the pollinating

Pawpaw flower (DickClarkMises) Public Domain

​The fruits, which are berries, are large yellowish-green to brown ovals, similar to mango or papaya. They have pale to bright yellow flesh and can be up to 6” long and weigh more than one pound. Each fruit contains several large seeds. Ripe fruits fall from the tree, but you can pick them just before that happens.

Pawpaw fruit (Manuel.conde) Public Domain

The bark, fruit, and leaves of pawpaw trees contain a naturally occurring insecticidal neurotoxin, called annonacin, which has been linked to palsy and Parkinson’s disease, but you’d have to eat an awful lot of pawpaws to have any problems. Zebra swallowtail (Protographium marcellus) larvae feed exclusively on pawpaw and its cousins. The toxins contained in the leaves provide these butterflies with protection from predators throughout their lives. Even though the swallowtail caterpillars eat the leaves, they do not generally cause problems.

How to grow pawpaw trees

Zebra swallowtail (Meganmccarty) Public Domain

Pawpaws can be grown in USDA Hardiness Zones 5—9. While it is easiest to start your tree from root suckers or bare rootstock, you can use seeds that have been kept moist and stratified in cold storage for 2 or 3 months. The problem with seeds is that each seed is genetically different from its parent and siblings, so there’s no way to know for sure what you’ll be getting. On the flip side, root suckers have very few roots, while seedlings started from seeds have substantial taproots that help them get established.

Pawpaws can be grown in containers at first, but will eventually need to be put in the ground to stay healthy and productive. Since fruit is produced on new growth, annual pruning is important. Being deciduous, it is easy to prune pawpaw trees in winter. Pawpaws should be fed in early spring and again in early summer.

Pawpaws prefer slightly acidic, moist soil with good drainage. These trees grow best in sites with strong morning sun and afternoon protection.

Problems with pawpaws

Pawpaws suffer from surprisingly few diseases or pest problems when compared to other orchard fruits. The most common problem faced by pawpaw growers is insufficient pollination. While pawpaw trees have both male and female flowers, they cannot pollinate themselves, so you will need more than one tree. You can improve pollination rates by hand-pollinating. Commercial growers have been known to spray their trees with fish emulsion or hang chicken necks in their trees to attract the appropriate pollinators. I don’t see myself hanging chicken necks in trees. Ever.

But a cluster of low-maintenance pawpaw trees along a back fence sure sounds appealing.