Late summer and early fall might not seem like a very tropical time in Missouri, but it is the best season to find one of the last remaining pieces of the state’s tropical past. I’m talking about the largest edible native fruit in North America – the elusive paw paw. Despite the fruit’s uniquely exotic flavor, and the fact that it grows throughout the Midwest, you won’t find the paw paw in most groceries, which means if you want to taste it, you have to set off into the woods, which is exactly what I did on a recent afternoon.
I made my way out to Rock Bridge State Park where I knew there was a large paw paw patch along the Spring Brook trail. The paw paw trees sit on the banks of Little Bonne Femme Creek, in what's known as the riparian zone - the interface between water and woodland. The patch consists of dozens of paw paw trees, ranging all the way from three to 20 feet in height. The fruits come directly off the branches, but looking up into the canopy, I wasn't able to find a single one.
Paw paw trees form colonies, with the original tree producing genetically identical clones that grow outwards. To produce their fruits, they have to be cross-pollinated with other, genetically distinct trees, which can be kind of a crap-shoot in the wild. But if you want a more reliable source of paw paw, you can always grow your own.
Lesa Beamer, a professor of biochemistry at the University of Missouri planted a handful of paw paw trees in her back yard. She ordered her seedlings from the Missouri Department of Conservation, which grows paw paw and other native trees to sell from its nursery near Licking.
"I’ve had blooms on the plants for a number of years but never got any fruit, and so when I was online someone suggested doing hand pollination and so that is what I did back in April," Beamer explained.
To pollinate her plants by hand, Beamer used a paintbrush to collect pollen from the male flowers of one group and painted them onto the female flowers.
"At first it was disappointing because nothing happened, and then like a month later I saw these little tiny green things starting to come out and then I was excited."
The paw paw fruit itself is pale green and vaguely avocado-shaped. As it ripens, towards the end of August and into early September, it yellows. But, as Patrick Byers explained to me, that's not the best indicator of ripeness.
"The best way to tell if a paw paw fruit is ripe is not so much by looking as it is by touching," Byers said. "When you hold the paw paw fruit in your hand and gently squeeze it, it should yield under the pressure of your fingers."
Byers is a regional horticultural specialist with the University of Missouri Extension. He’s been researching different paw paw cultivars for years, trying to solve some of the issues that have kept paw paws out of grocery stores.
"First of all, it is a very perishable fruit," he explained. "It’s somewhat analogous to a banana in that aspect, in that it has a short shelf-life and would have to be handled very carefully at harvest, because it is softening at that point."
The cultivars the extension has been testing aim to produce faster growing trees that produce the tasty fruit more reliably. The actual taste of the paw paw can be hard to describe.
For Byers, "It combines a number of tropical fruits and flavor." He added, "When I eat a paw paw I think of a combination of banana, mango, perhaps a little bit of papaya mixed in, but it is definitely a tropical flavor."
If you want to experience the taste of the fruit for yourself, there is still time – paw paw season typically lasts through the end of September.