Pawpaw

by Andrew Moore

  Our hike is through the western edge of the Allegheny Plateau. A shaggy carpet of green ramps (Allium triccocum) covers the rolling hills, while canopies of beech, ash, tulip poplar, and stands of hemlock filter the spring sun. Mayapple emerges from beds of last year’s fallen leaves like miniature woodland umbrellas, and in a few months it too will produce a unique edible fruit, whose flavor Steve likens to starfruit. In 1818, William P. C. Barton—surgeon in the US Navy and University of Pennsylvania professor of botany—wrote that mayapple was “one of the most important medicinal vegetables indigenous to our country.”1 Farther on, spicebush grows up to six feet tall, its leaves like pawpaws’ but miniature. Spicebush too holds potential—its leaves for tea, and its berries for spice. Chris Chmiel has even launched a Spicebush Summer Solstice Festival, hoping to raise the profile of the “Appalachian Allspice.” We’ve hiked only a short distance, but already there is ample evidence that the potential of the eastern forest is vast.

  We push on. Steve is looking for familiar landmarks, including an equestrian trail that will lead us to the first pawpaw patch. Although he earned a master’s degree at the University of Michigan in 1996, and published a study describing a new genus of woody vines found in Mexico and Central America, Steve hasn’t done too much scientific work since. I ask him what made him want to do this work, and why now? The question seems to catch him off guard, and he turns it around. “Why are you writing this book?” He then gives an honest and straightforward answer. “Basically it’s an excuse to get permits to go anywhere I want, and look for pawpaws,” he says, laughing. “Hunt pawpaws, hunt mushrooms.” It’s a good answer; in many ways, it’s my own.

  In 1995, Steve traveled to Suriname, on the Caribbean coast of South America, and fell in love with the diversity of fruit there. But as he continued to travel he developed a love–hate relationship with the region. When he arrived in the tropics, he wanted to be home; when home, he longed to be away. “When I finally realized I was not going to move to the tropics, I think a pawpaw orchard became the perfect substitute,” he wrote to me in an email. “The Eastern US is basically the tropics during summer and pawpaw would have fit perfectly among those fruits I first experienced on my visits to the tropics.” Tropical Appalachia. In the summer we share the heat and humidity, the dense green forests, cicadas, mosquitoes; they have passionfruit, we have passion flower; they have allspice, we have spicebush; there, guanabana, here, pawpaw. Indeed, the pawpaw’s exotic appearance has long been noted. In 1897, Wisconsin journalist Reuben Gold Thwaites floated a skiff down the length of the Ohio River; of one stretch, he wrote, “For the most part, these stony slopes are well wooded with elm, buckeye, maple, ash, oak, locust, hickory, sycamore, cotton-wood, a few cedars, and here and there a catalpa and a pawpaw giving a touch of tropical luxuriance to the hillside forest.”2 Occasionally such tropical-temperate analogies were made of the southern regions themselves. A 1913 Amazon River adventure novel finds several Americans in South American jungles, and among their new experiences they encounter the region’s fresh fruit. “The natives call ’em chrimoya . . . See, it is a pie, already made . . . Inside was a delicious soft pulp, thickly sown with black seeds. It reminded the boys of the Indiana pawpaw.”3

  Growers and enthusiasts, or anyone who gets excited about the fruit, will often say, “It’s a tropical fruit that grows right here,” right here meaning some temperate place far from the Caribbean, or from south Florida. The farther north you go, the greater the annual snowfall and percentage of days with below-freezing temperatures, the greater the excitement. For those who travel, dream of traveling, or have moved to the United States from tropical regions, the pawpaw is a way to make the world a bit smaller, to bring faraway places to a backyard in Ohio, Indiana, or Michigan. And understanding the history of Asimina triloba, its evolution and relationship to other Annonaceae, does make the world seem more connected—and is a reminder of how much there is yet to know about the plants that surround us; the million-year journeys these plants have taken to get where they are, and to appear as they do. The pawpaw—flowering here in Stebbins Forest—is in fact a tropical plant that willed itself, over millennia, to thrive where it shouldn’t.

  We arrive at the first patch, and after I clumsily slide down a steep bank to the creekbed, we start to collect data. The pawpaw flowers look like hundreds of cut red roses, nodding downward from leafless twigs. In addition to studying fungi, Steve is attempting to define what constitutes a patch—where one stops and another begins. In some places the divide is clear; in other forests, the “patch” never ends, continuing on and on. In his study, a patch “is defined as a group of pawpaw stems separated from other stems by at least three meters.” According to one study, pawpaws have been able to increase in some forests by as much 724 percent in just a few decades.4 That number is astounding, but, anecdotally at least, I’ve seen evidence of patch prowess. The previous summer I traveled to Lancaster County, Pennsylvania, to see a pawpaw grove described by locals as the “largest pawpaw patch north of the Mason-Dixon.” It delivered. A walking trail, hugging a steep bluff overlooking the Susquehanna River, wound through a seemingly endless grove of pawpaws. But was it one massive patch, clonally replicated, or were there many unique trees among the thousands? Here in Stebbins, the patches are more manageable. We’re able to identify one large thirty-foot tree, with smaller trees radiating out from its center. We record the diameter of flowering trees, collect soil samples, and march on.

  How patches spread is still poorly understood. Recently, Kentucky State University researchers conducted a study to determine whether various patches of pawpaws were established by suckering, or water transport of seed. The difference would mean that a patch was either a group of clones, or made up of genetically distinct trees. Researchers selected three wild patches and determined through DNA fingerprinting that each was genetically distinct. One patch was entirely clonal; a single tree had multiplied itself through its root suckers. Another patch, however, contained greater genetic variation, and its location along a stream suggested the involvement of water transport, or animal transport of seed. The takeaway from the study was that pawpaw patches are predominantly made up of clones, but most do have genetically distinct seedlings interspersed throughout.5

  In late winter, pawpaw flower buds begin to swell. Alabama grower Dale Brooks calls these buds “little fuzzy BBs,” a description I find fairly apt. Both leaf and flower buds are covered in a dark-brown, thick pubescence, which creates the fuzzy appearance. Then, in April or May, pawpaw flowers emerge. Desmond Layne observed that in the Ohio Valley and mid-Atlantic states flowers come on immediately after the peak of dogwood blooms. Once they have matured in size, the flowers will have outer and inner layers of three maroon-colored petals.6

  It’s often said that pawpaw flowers smell like rotting meat, and that this is in order to attract pollinators, the various blowflies and carrion beetles attracted to decomposition. But beyond being grotesque, that description might not be altogether accurate. Besides, we pawpaw lovers need a more pleasant analogy for the flower of our favorite fruit. Enter scent scientist Katherine Goodrich. “Until recently, the scientific study of scent was . . . relatively confined to the perfume or wine industries,” Goodrich writes. But advances in scent sampling and analysis techniques have broadened the scope of scent study, and scientists “are increasingly interested in the role that plant scent compounds play in plant-animal interactions.” In her research, Goodrich has found that the maroon-pigmented Asimina species “all share yeasty ‘fermentation’ floral odors,” specifically compounds that give the flowers “a scent similar to red wine or rising bread dough.” But flesh persists as well. Goodrich goes on to say, “The small maroon flowers with yeasty scents may represent mimics of food substrates or brood sites for pollinating beetles and/or flies. It is possible . . . that the odors produced generate a learned response from pollinating insects.”7

  The pawpaw flower is not alone in nat
ure as a mimic of fermentation. The largest flower in the world belongs to a species known as Rafflesia arnoldii, or corpse flower, and is found in the rain forests of Indonesia. Measuring up to three feet long and weighing up to twenty-four pounds, this maroon-colored bloom emits an odor said to be horrible and repulsive, “similar to that of rotting meat.” Another enormous tropical flower, Amorphophallus titanum—also colored burgundy red on the inside—is similarly scented, and is also known as the corpse or cadaver flower.8 And in North America, among the deciduous forests’ spring ephemerals is Trillium erectum, a small, nodding woodland wildflower that looks strikingly like the blooms of pawpaw. Its maroon flowers are, you guessed it, commonly described as smelling like a wet dog or rotting meat. Furthermore, each of the above examples is pollinated by flies and beetles.9 But again, let’s use red wine and rising bread dough when describing pawpaws, please.

  Flies and beetles are listed as the primary pollinators of pawpaws, but they’re not the only insects conducting business inside the flowers. The pawpaw peduncle borer (Talponia plummeriana), a moth larva, lays eggs within the flower and then consumes it. Although much scientific research remains to be done, Neal Peterson has closely observed these relationships for decades. “There seems to be a whole ecology in the flowers,” he says, “between the insects coming in and the spiders that are there waiting to eat the insects.” Occasionally, human beings are part of that ecology.

  Botanically speaking, pawpaws are perfect, which means they have both male and female reproductive parts. Being protogynous, the female parts (the pistil) come to maturity before the male parts (the stamen). Yet despite having all the necessary equipment, pawpaws don’t enjoy reproducing alone: They’re self-incompatible and require a genetically different tree/flower for cross-pollination (however, the Sunflower cultivar is widely reported to be self-fertile). So for various reasons, pawpaw growers occasionally choose to get involved. “It’s all very easy,” Neal Peterson writes, “but—like human sex—it isn’t necessarily obvious how to do it the first time.”

  Pawpaw flowers begin as females, and later become male, a fact that actually discourages self-pollination, since pollen is produced last, after the flower’s receptive female parts have transitioned. In the first stage, petals are held tightly together, forcing flies and beetles visiting for nectar to brush against the stigmas. During this time, the petals turn from green to maroon, and once the flower has darkened, the fetid aroma—of red wine, rising dough, flesh—intensifies. The flower is now male. Anthers turn from green to brown and release their yellow pollen. An insect pollinator must then travel to a female flower of a different tree to create fruit. As human pollinators, we have a certain advantage: We can collect pollen one day and return another. Once pollen has been collected, the orchardist can use these visual cues to then pollinate the female flowers. “I find that I get the best results on a perfect spring day, when the sun is bright, the air is warm, the breezes gentle or not at all,” Neal Peterson writes. “I don’t do it in the early morning or late in the day. When in doubt about how to do it, think like a flower, think like a beetle.”10

  Steve and I are lost. It’s okay, he tells me, it happens every time. We have GPS, but after a few minutes we conclude that for whatever reason the maps Steve downloaded won’t merge with the placemarks, so we’re looking at free-floating pinpoints with no context. Steve discovered the patch we’re looking for a year ago. It produced a good amount of fruit, even when other patches didn’t during last year’s hot, dry summer. The fruit wasn’t too bitter either, he says, and neither vibrant orange nor stark white.

  One theory that Steve is contemplating is that the pawpaw may affect surrounding forest composition chemically via its Annonaceous acetogenins. Another factor might be leaf size: A dense patch of broad-leafed pawpaws could shade the forest floor to the exclusion of other species. In his Geauga County tramping, Steve notices that pawpaws overwhelmingly occur in the understory of beech, sugar maple, and black cherry. Kirk Pomper also suggests pawpaw might inhibit the spread of invasive exotics, such as Japanese honeysuckle. However, his research shows that only the largest, densest pawpaw colonies stand much of a chance in this fight.

  We’re now following blue blazes because at least we know they will lead us to some destination, though Steve isn’t sure what that will be. We cross TRAIL CLOSED signs, ominous clouds hover above us (it has been raining for days), and a cool breeze blows, signaling more precipitation. Steve isn’t worried. After about a mile we stumble upon the next pawpaw patch. I’m getting hungry and have already eaten my apple, so I munch on the greens of as many ramps as I can pick, though it seems I could pick for days without doing much harm. In this forest, I can anecdotally confirm that ramps grow quite well at the roots of pawpaws. We collect the last of the day’s data and manage to beat the rain back to the stream and to the car.

  We come out of the woods and return to Steve’s orchard. In addition to the trees he has ordered, he is raising trees from seed. KSU recommends sowing seeds to a three-centimeter depth (about an inch and a quarter) in a “moist, well-drained soil or other medium that has good aeration.” California grower Ray Jones observed that planting seeds one inch deep, with the small end up, and after a warm-water soak, worked best.11 And experiments have shown that germination is hastened by ten days if the soil is heated to 29 to 32 degrees Celsius (or 84.2 to 89.6 degrees Fahrenheit) after sowing.12 At least one OPGA member starts his seeds in containers in his basement, which are placed on heating pads. Taking things a step farther, Arkansas’s Blossom Nursery pre-germinates all seeds before planting its nursery stock in containers (and offers excess germinated seed for sale online). Because of its long taproot, pawpaws should be grown in tree pots—four-by-fourteen-inch containers are commonly used. Other less orthodox methods include PVC pipe and, my own method, ten-and-a-half-inch repurposed milk and juice cartons.

  According to pawpaw grower Barb Ernst, there are two rules basic rules to follow for the successful germination of pawpaw seeds. Rule number one: “NEVER LET THE SEED DRY OUT.” And rule number two: “NEVER LET THE SEED DRY OUT.”13

  They are good rules to follow. Once it has been cleaned, pawpaw can be stored in a moist medium, such as peat or sphagnum moss, and then sealed in a ziplock bag. Before they will germinate, pawpaw seeds need to overwinter. Luther Burbank once wrote that pawpaw “has a habit of ‘thinking it over’ six months in the greenhouse before it begins to sprout.”14 This overwintering process, called stratification, occurs naturally in the wild, but can be replicated with even more reliability in your refrigerator at around forty-one degrees Fahrenheit (but not your freezer—the deep freeze can kill the seeds) for approximately one hundred days. At his home, Steve stores seeds in old yogurt containers with a damp cellulose sponge that has been “soaked and wrung out mostly.” “Another method is to plant them in the fall,” Corwin Davis once advised. “Mice and squirrels will not bother them. If fall planted, mulch with leaves to prevent heaving.”15

  Traveling and farming don’t always go hand in hand, especially when you have vulnerable young pawpaw treelings planted in full sun. Last summer, Steve and family spent a couple of weeks in Russia, Tatiana’s native country. Since he had young pawpaw trees to worry about, he installed a drip irrigation system, which was a good thing since northeast Ohio was hit with drought. It saved most of the trees from dying, but this spring they’re hardly thriving, and many look miserable. Still, as the season progresses, only a few prove dead. Steve will plant fifty additional pawpaw trees later this year. When these mature, they won’t require much upkeep, so once the orchard is established, trips to Russia, Suriname, or wherever the family wants to visit will be much easier.

  Steve must wait several more years before he gets even one fruit from his young orchard. In the meantime, he sells vegetables and berries at local farmers markets. He has even sold foraged pawpaws to a local ice cream maker. He’s making sales, which is obviously the farmer’s goa
l, but he’s also trying to get a head start on the marketing work he’ll eventually be faced with when the cultivated fruit is ready. “What’s a pawpaw?” customers will ask. “They grow here?”

  PART III

  WAY DOWN YONDER: TRAVELS IN THE PAWPAW BELT

  — CHAPTER THIRTEEN —

  ST. LOUIS

  In September 1806, Captain Meriwether Lewis and Lieutenant William Clark were six months along their return trip from the Pacific Ocean. President Thomas Jefferson had ordered the expedition to find “the most direct & practicable water communication across this continent for the purposes of commerce.”1 It had been more than two years since the Corps of Discovery set out, and back in Washington it was feared that Lewis and Clark and the others were long dead. Though far from it, mortality surely crossed their minds when food supplies started running low. The crew was eager to reach home, but they suddenly began anticipating something else as well, as evidenced by the last sentence of a journal entry dated September 11: “The papaws nearly ripe.”

  A few days later, near the entrance of the Kansas River along the Missouri, Lewis and Clark went ashore to gather “pappaws or the custard apple of which this country abounds, and the men are very fond of.” The crew then shot an Elk, and “secured and divided” its flesh. They went forty-nine miles that day and encamped “a short distance Above Hay cabin creek.” The weather was disagreeably warm, but steady winds broke the suffocating humidity. And they were now well fed on a feast of native foods, including elk meat and pawpaws. It must have been a good year to have such abundance.