Q. When do pawpaw trees bloom? Four years ago, I started five trees with seeds from a fruit I bought at a market in Lancaster, PA. The trees are about six feet tall and healthy, but no flowers yet. This year I also purchased two different varieties of professionally started trees, as it appears cross-pollination is necessary to get fruit. How old do these trees need to be before they bloom? And will my trees from seed ever produce flowers?
- ---Diane in West Chester, PA.
- ---Doug in Douglassville, PA (near Reading)
Anyway, the pawpaw, though little known to most gardeners, is greatly treasured by both native plant and weird fruit enthusiasts—including our resident expert on all fruits weird and/or wonderful, Dr. Lee Reich, who points out that the pawpaw is the largest of the native American fruits.
Often called "The Banana of the North", pawpaws behave very much like their tropical namesakes; they grow in clusters, develop little black 'sugar spots' as they approach full ripeness and will continue to ripen off the plant if picked when nearly ripe. In his most recent book, "Grow Fruit Naturally" (The Taunton Press; 2012), Lee describes their flavor as "a pleasing mix of banana, vanilla custard, avocado, mango and pineapple."
But despite all that tropicality, pawpaws grow best in decidedly non-tropical areas—specifically USDA Zones 4 through 8. And although universally described as 'easy to grow', they are somewhat quirky plants in terms of growth and pollination.
For instance, Lee explains that those trees started from the seeds of a single fruit will grow into diverse adults that will flower and provide the necessary cross-pollination. But he adds that the seed to fruiting process takes about eight years, and thus recommends starting with named varieties of grafted trees, which will flower in two or three years. Just be sure to start with two different named varieties.
And look for potted plants. Pawpaws have a deep and sensitive taproot that doesn't transplant well, a tendency that even makes the planting of bare root stock difficult, warns Lee, as that root is extremely brittle.
Being native to forested areas, young trees started from seed require a bit of shade to survive their first few years; at least half a day without sun, warns Lee. But he adds that mature plants produce the most fruits in full sun, so an area where they'll outgrow their shade in a few years would be ideal for plants started from seed. (You don't have to worry about started trees; they can take full sun right away.)
Still, getting lots of fruit from young plants can be a chore no matter what the conditions, he adds, as the flowers (described by my pawpaw growing friend Rob Hammil as purple-ish and orchid-like) are pollinated by flies and beetles as opposed to bees. Some people hang meat in their pawpaw orchard to attract those flies; Lee recommends hand-pollination while the trees are young, which he describes in great detail in his earlier book, "Uncommon Fruits for Every Garden" (Timber Press; 2004). Mature trees, he adds, "bear plenty of fruit without any sexual intervention; in fact they can bear so heavily they sometimes break some of the branches."
Although they can be trained to appear in a managed landscape as impressive looking single trunked trees, pawpaws send up lots of suckering shoots and become thickets in the wild. Everyone agrees that these shoots are easily controlled with a lawn mower, and Hamill found them to be a valuable advantage when his wife commandeered the spot where his best tree was growing. He dutifully cut the big tree, and is now tending a number of shoots that had moseyed about 30 feet away as replacements. No matter what, keep your bearing trees close, he advises, noting that he gets the most fruit on trees that are within 25 feet of each other.
The flowers open late in the Spring, and the fruits mature towards the beginning of fall. And if you don't pick them promptly, they WILL fall. Because they are thin-skinned and delicate, having a cushioning mulch of shredded leaves or pine straw underneath becomes a necessity. (It also keeps the roots cool, which the plants like.)
You'll rarely see pawpaws for sale in markets as the fragile fruits don't travel or store well; they bruise easily and a fully ripe pawpaw is best eaten within a day or two. The proper way to enjoy this tropical treat, feels Lee, is to cut the fruit in half and scoop out the custardy insides with a spoon. Don't eat the skin, and be sure to spit out the toxic seeds—which you can then give to another potential grower of Northern bananas….