Foraging Fun: Asimina triloba

Pawpaws: one of the most curious and extraordinary of foraged autumn delights. These fruits can weigh in at a 1/2 pound or more and are produced individually or in groups of up to 5 or 6 from small, thicket forming trees found wild in only a few sites in southern Ontario. They have a wonderfully sweet aroma when ripe that easily fills the whole room with a tropical fragrance. The flesh has a soft, creamy texture and a succulent custard/banana flavor. The ripe fruit won’t last for long and is difficult to adequately preserve (save for attempting to scoop out all of the flesh and freeze it before it oxidizes). They are truly unlike anything else that one can encounter either in the wild or being cultivated as a food tree in the whole of Canada.

A typical cluster of pawapw frut. The leaves are rather large, long and elliptical, gently tapering to a pointed tip with entire margins and a short, distinctly grooved petiole.

Lucky, for both myself and the pawpaw, each fruit contains anywhere from 2 to 8 large dark colored bean-like seeds. These seeds, if kept moist by storing them in a zip-lock bag with a lightly moistened paper towel in the refridgerator or in a bucket/pail of moistened sand in the cellar or garage will be ready for planting come spring. Pawpaw seeds, like the seeds of many plants which grow in regions that experience freeze and thaw cycles, require a period of cold stratification in order to break down growth inhibitors which prevent the seeds from germinating right after being sown and then immediately being killed off by frost. Be patient though, as the seeds often take 1-3 months to germinate once the temperature of the soil warms up sufficiently. Make sure to keep the containers/soil from dying out, as germination can drop quite steeply if the seeds dry out too much.

Why would you want to go through all this trouble? To grow your very own pawpaw tree(s) of course (it’s recommended that you have at least 2 trees to ensure adequate cross-pollination). That way, you won’t have to know where to find this illusive species in the wild, which is few and far between at best considering that pawpaws are restricted to the Niagara peninsula and scattered localities throughout southwestern Ontario. Unfortunately for those of us who live in other regions of Canada, pawpaw trees are quite sensitive to the cold and therefore cannot be reliably grown much further north than hardiness zone 5a or 5b in Canada.

Ripe pawpaws are yellow-green in color, yield to gentle pressure and are wonderfully aromatic. They are best peeled or cut in half and eaten with a spoon like an avocado. The seeds are easily separated from the flesh and can be stored for germinating until spring.

There are one of only a handful of species belonging to the predominately tropical Annonaceae family of plants which includes the custard apple (Annona reticulata), soursop (A. muricata) and cheyimoya (A. cherimola). None of these species can tolerate prolonged exposure to subzero temperatures except A. triloba, which diverged from it’s heat-loving brethren and ventured northward to colonize the eastern seaboard of North America. Confusingly, Asimina triloba is sometimes also referred to as ‘custard apple’, as well as other interesting folk names such as ‘poor man’s banana’ or simply ‘wild banana.’

The trees, once established, flourish in full sun or partial shade and can even grow in the shade of a mature forest although they will flower and fruit less than those trees which have unhindered sunlight exposure. Naturally occurring in rich sheltered valley bottoms pawpaws appreciate fertile and free-draining soil and dislike strong winds or exposure, so are best planted behind a screen of other trees or near buildings or other structures and not on open hillsides.  Mature pawpaws have a tendency to sucker, although these shoots are slow growing and easily kept in check with regular pruning or if you have the space, encouraged to grow into more trees. Other than that pawpaws are nearly maintenance free after their first year and assuming they are happy with their situation are even drought-tolerant and usually begin bearing fruit at around 4-8 years of age.