As the largest native fruit to our region, Pawpaws are a favorite for edible landscaping. They can handle cold Winter temperatures and shady lighting and they have few pests. In fact, their leaves contain toxic acetogenins that can be digested by very few insects. One of those however is the Zebra Swallowtail butterfly larvae. As caterpillars, Zebra Swallowtails only feed on the leaves of Pawpaws, so keeping the Pawpaw population strong is vital to their survival.
But we wanted to talk about Pawpaws today because of another interesting relationship they have with insects! If you have a Pawpaw tree in your yard, you may have begun to see their unusual reddish-brown, downward facing flowers appear. They begin to bloom around the same time that the tree leafs out. But these flowers won’t be touched by butterflies and bees; Pawpaws rely on carrion beetles and flies to pollinate their flowers. These species, like many pollinators and plants, have co-evolved so that the Pawpaw flower actually smells faintly of rancid meat to attract the right bugs. One old-timey pollinating trick is to hang roadkill from your Pawpaw trees to attract more pollinators -- but we don’t necessarily recommend it!
As the owner of a Pawpaw tree eager for fruit, there are a few important things to keep in mind. Although Pawpaws have “perfect” flowers (containing both the male and female reproductive parts in each flower) their flowers are also protogynous, which means the male and female parts of the flower mature at different times during the season. Plants evolve to become protogynous in order to prevent self-pollination and to increase gene diversity. Therefore, to have fruiting Pawpaws you not only need two trees near each other, you need two trees that are genetically different from one another!
The Pawpaw is a beautiful tree with silver bark and large deciduous leaves. If you haven’t ever tried the fruit make sure to get some this fall when they come into season- try your local farmer’s market in late August and be on the look-out for fun pawpaw festivals happening from Ohio to Kentucky to Maryland!