The pawpaw, Asimina triloba, is a tree of temperate humid zones, requiring warm to hot summers, mild to cold winters, and minimum of 32 inches (80 cm) of rainfall spread rather evenly throughout the year, with the majority falling in spring and summer. It is hardy to zone 5 (-15F/-25C). Pawpaws are native over a wide range of latitude, from the Gulf Coastal plain to southern Michigan.
One of our customers in Northfield MN, has been growing our pawpaws for several years now. (Zone 4) His advise start with a good strong specimen.
Site, Soils & Habitat
Although the pawpaw is capable of fruiting in the shade, optimum yields are obtained in open exposure, with some protection from wind (on account of the large leaves). The soil should be slightly acid (pH 5.5-7), deep, fertile, and well-drained. In habit it is a small tree, seldom taller than 25'. In the shade it has a more open branching habit with few lower limbs and horizontally held leaves.
Pollination, Natural & Artificial
Pollination is the major limitation to pawpaw fruit set. The flowers are protogynous, meaning that the stigma (the female receptive organ) ripens before the pollen, and is no longer receptive when the pollen is shed. Thus the flower is designed not to be self-pollinated. In addition pawpaw trees are self-incompatible, requiring pollen from a genetically different tree in order to be fertilized. Finally, the natural pollinators of the pawpaw (various species of flies and beetles) are not efficient or dependable. Although it requires a little extra labor, hand pollination can be well worth the effort and can be done as follows: Using a small, flexible artist's brush, transfer a quantity of fresh pollen from the anthers of the flower of one clone to the ripe stigma of the flower of another clone. Pollen is ripe when the little ball of anthers is brown in color, loose and friable; pollen grains appear as yellow dust on the brush hairs. The stigma is ripe when the tips of the pistils are green and glossy, and the anther ball is still hard and green. Do not overburden the tree with fruit, as this will stress the tree, resulting in smaller than normal fruit, and may cause limbs to break under excessive weight.
Eurytides marcellus, (Zebra Swallowtail), whose larvae feed exclusively on young pawpaw foliage, but is never in great numbers. The adult butterfly is of such great beauty that this should be thought of as a blessing. Deer will not eat the leaves, twigs, or fruit. USES: The primary use of pawpaws is for fresh eating. The easiest way to eat them is to cut them in half and scoop the flesh out with a spoon; the large seeds, scattered throughout the flesh, are then simply spit out. On a hike or picnic, you can tear an opening into one end and squeeze the flesh into your mouth. In cooking, the pawpaw is best suited to recipes that require little or no heat. Because the pawpaw's flavor compounds are very volatile, prolonged heating or high temperatures destroy their characteristic flavor. Pawpaw works well in ice cream, sorbet, chiffon pie, and mousse, and combines well with mint. On account of its flavor resemblance to banana, it may be substituted in recipes such as banana bread.
Ripe pawpaws are best on the tree just about ready to drop from the tree. The skin will turn to a lighter tint of green. The flavor is like custard. If the skin is yellow and brown, (brown like an overripe banana) the pawpaw although still good to eat is not as good in my opinion. Allegheny and Rappahannock are early ripening. Shenandoah is early - mid season to late ripening. Wabash, Susquehanna and Potomac are late ripening.
Quality pawpaws compare favorably to the best pears, peaches, and mangoes of the world. They can vary considerably in size, depending on the cultivar and the number of seeds in each fruit, but should ordinarily weigh between 5 ounces and 1 pound. They should appear plump and round in shape--the largest, plumpest pawpaws often resemble mangoes. the flesh should be neither too soft or too firm: it should have a custard texture that is smooth, melting, and luscious. The flavor should be sweet, fragrant, and complex, with a satisfying and lingering aftertaste.
Pawpaw sorbet made by Chef Dan Nolan in Philadelphia. the pawpaw texture is naturally creamy, so it can be easily made into sorbet without the addition of any cream. It was absolutely delicious!