Expedition consumed pawpaws during their travels. Thomas Jefferson planted it at Monticello, his plantation in Virginia. Legend has it that chilled pawpaw fruit was a favorite dessert of George Washington. Research Kentucky State University (KSU) has the only full-time pawpaw research program in the world; it was started in 1990 with the aim of developing pawpaw as a new tree-fruit crop for Kentucky. Pawpaw is the largest native fruit in North America and has very few diseases compared to other orchard crops. KSU is the site of the USDA National Clonal Germplasm Repository for Asimina species and the pawpaw orchards at KSU contain over 1,700 trees. Research activities include germplasm collection and variety trials, and efforts are directed towards improving propagation, understanding fruit ripening and storage, and developing orchard management practices. Cultivation is best in hardiness zones 5-9 and trees take 7–8 years from seedling to fruiting. KSU has created the three cultivars KSU-'Atwood', KSU-'Benson', and KSU-'Chappell', with foci on better flavors, higher yields, vigorous plants, and low seed-to-pulp ratios. Cultivation Cultivation is best in hardiness zones 5-9 and trees take 7–8 years from seedling to fruiting. Cross-pollination of at least two different genetic varieties of the plant is recommended. Scholarly research is insufficient for horticulturalists to adopt best methods for attracting insect pollinators, as effective pollinators have not yet been distinguished from casual insect visitors. Therefore, some growers resort to hand pollination or use pollinator attractants, such as spraying fish emulsion or hanging chicken necks or other meat near the open flowers to attract pollinators. While pawpaws are larval hosts for the zebra swallowtail butterfly, these caterpillars are usually present only at low density, and not detrimental to the foliage of the trees. Pawpaws have not been cultivated for their fruits on the scale of apples or peaches, primarily because pawpaw fruits ripen to the point of fermentation soon after they are picked, and only frozen fruit stores or ships well. Other methods of preservation include dehydration, production of jams or jellies, and pressure canning (using the numerical values for bananas). Methods of separating seeds from the pulp are still in the experimental phase. Mechanical methods are most efficient, but any splitting or injury of seeds can contaminate the remaining pulp with seed poisons. Cultivation of pawpaws for fruit production has attracted interest, particularly among organic growers, as a fruit with few to no pests that can successfully be