Pawpaw

(Asimina triloba)

Pawpaw
‘Davis’ pawpaw

Cultivars tested

‘Davis’, ‘Pennsylvania Golden’

Description and site preference

Type and size – small pyramidal tree 10-25 feet, spreading by root suckers
Hardiness zone – 5-8
Exposure – full sun in northern areas, shaded during establishment years
Soil – most soils with pH 5.0-7.0
Drainage – well-drained

Economic factors

Years to harvest – about 3 years with grafted material
Maintenance – plant establishment takes special care
Life of planting – 30+ years
Machine harvest potential – not an option
Suitable markets – fresh, some processing but heat reduces flavor

Pawpaw with flowers and emerging leaves
Pawpaw with flowers and emerging leaves

Notable features

Nutritional highlights – higher in some vitamins, minerals and amino acids than apple, grape and peach
Adaptability – good once established
Pest issues – few in most locations, none observed in test plot
Invasive potential – native, suckering easily controlled
Environmental benefits – deep taproot, should make it a good dynamic accumulator of minerals

Integration characteristics

Shared management – low, specialized
Shared equipment – intermediate
Shared processing – low, probably specialized
Co-marketing – intermediate, special handling for fresh fruit

Integration potential – good ecologically

This plant has a deep taproot that could salvage minerals for shallow rooted companion crops, which in turn could attract beetles and flies required for pollination. Economic sustainability will depend on site-specific conditions, cultivar selection and local/regional marketing options.

Dormant Pawpaw
Dormant ‘Pennsylvania Golden’

History and background

Pawpaw is the largest native North American fruit. Its current range is south of New England, north of Florida and as far west as Nebraska. It is a small, pyramidal tree with long, drooping, tropical-looking leaves. Pawpaw is probably too soft and perishable as a fresh fruit for the conventional food chain, but might work well in a local/regional marketing system, as well as direct marketing.

It is thought to have been a favorite fruit of Native Americans who are credited with spreading it across the eastern U.S. Some people apparently have an allergic reaction (see this article by Kathy Bilton) — stomach and intestinal pain — when eating pawpaw. Its twigs and small branches contain a natural pesticide, which also seems to serve as a repellant to browsing animals, including deer.

Pawpaw has a strong appealing aroma and a flavor similar to a blend of mango, pineapple and banana. In fact, it is often call “banana of the north” for its texture and flavor. It is best eaten fresh or frozen and dried for later use, as heat reduces flavor.

Observations at Carandale Farm

Two plants each of ‘Davis’ and ‘Pennsylvania Golden’ were ordered from One Green World in 2003.

  • Pawpaw have long brittle taproots, making them difficult to transplant. One of each variety survived for cross pollination.
  • Both cultivars were slow to establish and languished for about five years. The clay loam soil is probably too heavy for them.
  • ‘Davis’ has taken off and grown well in the last five years. It is now more than 10 feet high and has blossomed for the past three years.
  • ‘Pennsylvania Golden’ is only about six feet tall and hasn’t yet bloomed, so there has not been any pollen to fertilize ‘Davis’.
  • Foliage looks healthy with no pest damage.

Discussion

Historically, Pawpaw has had little professional breeding attention, but Kentucky State University now has a full-time pawpaw research program. There are more than 40 pawpaw cultivars commercially available, either having been selected in the wild or the result of breeding efforts of hobbyist. Very little scientific research has been done on commercial pawpaw production.

Pawpaws do not thrive on heavy or waterlogged soil. They need cross pollination, and since the usual pollinators are not attracted to the flowers, this can be a problem. Their co-evolved pollinators may no longer exist, and the various species of flies and beetles that are attracted to the flowers are not efficient or dependable pollinators.

Pawpaw is said to be cold hardy to -25 degrees F (Zone 4), but it requires at least 160 frost-free days and warm temperatures to ripen the fruit. The Carandale test site is probably on the northern fringe for commercial production, but as the climate continues to warm, the range will probably move north. The economic potential of this uncommon fruit has yet to be determined, but with breeding and selection of regionally adapted cultivars and development of self-fruitful types there is a bright future for pawpaws. Observations of the cultivars in the test plot will be continued.

References

Uncommon Fruits for Every Garden, by Lee Reich
Kentucky State University
California Rare Fruit Growers

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