This document provides an overview of pawpaw production, including culture, pests, harvest, post-harvest handling, marketing, and research. It summarizes that pawpaws have potential for commercial development, are native to eastern North America, and thrive in zones 5-8. Major research efforts aim to identify best cultivars and management practices to support commercialization.

1. A project of the National Center for Appropriate Technology 1-800-346-9140 • www.attra.ncat.org
Pawpaw—A “Tropical” Fruit
for Temperate Climates
By Guy Ames and This publication is intended as
Lane Greer, NCAT Agri- a summary overview of paw-
culture Specialists paw (or paw paw) production,
Published 1999, including overall culture, pests,
Revised 2001 harvest, post-harvest, market-
ing, and research which seeks to
Revised 2010 by Guy develop the pawpaw’s potential
Ames, NCAT Horticul- for commercial development.
ture Specialist
© NCAT
Introduction
T
Contents he pawpaw (Asim-
Introduction ......................1 ina triloba) has great
Culture .................................1 potential for commer-
Harvest and cial development. Though the
Postharvest Handling ....3 pawpaw’s only near relatives are
Marketing ...........................3 tropical and the pawpaw looks
Plant Extracts as like a mango and tastes like a "KSU-AtwoodTM" photo courtesy of Kirk Pomper, Kentucky State University.
Anti-carcinogens banana, it is not tropical but is
and Insecticides ...............3
native to most of the eastern U.S. and even into Dr. Kirk Pomper at Kentucky State Univer-
Summary ............................4 Canada. The pawpaw grows best in areas with hot sity (KSU) announced in 2010 the first release,
References .........................4 summers and cold winters (USDA Zones 5-8). It ‘KSU-AtwoodTM’, from KSU’s pawpaw breed-
Websites .............................4 is hardy and relatively pest-free, and its tolerance ing program. With a flavor combining those of
Plant Sources ....................4 to shade makes it suitable for intercropping with banana, pineapple and mango, ‘KSU-AtwoodTM’
other trees. In addition, the pawpaw has genetic shows promise as a commercially available culti-
variability that can be used to improve the plant. var (Kentucky State University Pawpaw Project).
A major research effort centered at Kentucky
State University and involving a few other uni- Culture
versities (including Cornell, Clemson, Pur- Pawpaws thrive in moist, fertile, well-drained
due, Ohio State, Iowa State, and Oregon State) soils having a pH of 5.5−7.0. Although the paw-
should contribute significantly to the commer- paw tolerates shade, it produces best in full sun-
cial development of this crop (Pomper, et al., light, as long as it receives enough water and is
The National Sustainable 1999). These universities have established iden- protected from high winds. The trees will grow
Agriculture Information Service,
ATTRA (www.attra.ncat.org), tical plots of pawpaw cultivars, which they hope from 12 to 25 feet tall and should be spaced at
was developed and is managed
by the National Center for
will identify the best cultivars and best manage- least eight feet apart.
Appropriate Technology (NCAT). ment techniques. They are breeding for the fol-
The project is funded through
a cooperative agreement with lowing desirable traits: yellow to orange flesh; According to Dr. Pomper, weed control around
the United States Department fruit size 10 ounces or larger; seeds small and trees, with straw or woodchip mulch, is impor-
of Agriculture’s Rural Business-
Cooperative Service. Visit the few; fruit of uniform shape and free of exter- tant to increase tree survival rates. Pomper
NCAT website (www.ncat.org/
nal blemishes; and mild, sweet flesh with no notes that voles that might be attracted to these
sarc_current.php) for
more information on unpleasant aftertaste. mulches do not damage pawpaw trees as they
our other sustainable
agriculture and
would apple trees.
energy projects.

2. Planting: Seedlings vs. Pollination
Grafted Trees The slightly foulsmelling flowers are fly polli-
There are a number of cultivars that produce nated, and that may be one of the reasons that
superior fruit. An unbiased description of most fruit set is so inconsistent in the wild. An old
of these cultivars is available at Kentucky State recommendation to hang road kill in your trees
University’s pawpaw website: www.pawpaw. to attract fly pollinators (Black, 2009) might
kysu.edu/reports.htm. Grafted trees of these actually be helpful if you have only a few trees,
named cultivars can be relatively expensive (up but Sheri Crabtree at Kentucky State Uni-
to $35 for a single potted tree; wholesale quan- versity says that hand pollination is probably
tities would presumably cost less per tree), so more effective…and less objectionable. She also
prospective growers might be tempted to plant offered that at Kentucky State’s relatively large
ungrafted seedlings. While seedlings are much research orchards, pollination has not been a
cheaper than grafted trees, there is so much major issue, probably because the presence of
genetic variability in the pawpaw that commer- so many trees is simply that much more attrac-
cial-scale growers will be taking a significant tive to pollinators. More detail about hand pol-
gamble if they plant ungrafted seedlings, and lination of pawpaw is available at a Virginia
they will not know the outcome of their bet for Cooperative Extension website http://pubs.ext.
around 5-7 years since it can take that long for vt.edu/438/438-105/438-105.html.
seedlings to begin bearing (grafted trees usually
start bearing in 3-4 years). Pests and Diseases
Propagation by seed is quite slow but not diffi- Pawpaws have very few pest problems. There are
cult. Either plant the whole fruit after collection, a few lepidopteran pests (caterpillars), the prin-
or separate the seeds from the fruit and sow about cipal one being the pawpaw peduncle borer. The
an inch deep. Fresh pawpaw seed must be strati- peduncle borer (Talponia plummeriana) burrows
fied (given a cold period). This can be done by into the pawpaw flower and causes it to drop.
holding the seed in refrigerated storage in plastic Usually, however, so little damage is done that
bags with moist peatmoss for at least four months this is not a serious problem.
and then sowing the following spring. If the seed Other reported pests include earwigs, slugs, San
is directly sown outdoors, it may take two cold Jose scale, and tent caterpillars. To discourage
periods before germination is initiated. Never dry earwigs and slugs, Ray Jones, a California paw-
the seed or freeze it; this will kill the seed. paw grower, ties a three-inch band of aluminum
If you live in an area where pawpaws grow foil around each trunk and paints the middle
wild, you might be tempted to transplant from two inches of the foil with Tanglefoot® (Pyle,
the wild, but wild pawpaws have long taproots 1992). San Jose scale can be controlled with dor-
which are very easily damaged. Often pawpaw mant oils. Tent caterpillars can be physically
trees in wild patches are actually rootsuckers removed from the tree by cutting out the “tent”
from the original tree with poorly developed or the branches holding the tent.
root systems; these rootsuckers do not transplant Phyllosticta and flyspeck or greasy blotch (Zygo-
well. Even nursery-grown pawpaws are ordinar- phiala jamaicensis) can be problems of pawpaw.
ily quite difficult to transplant. They have fleshy, This occurs only during periods of high humid-
brittle roots with very few fine hairs, which ity and frequent rainfall. Dense foliage and lack
inevitably get damaged when transplanting. of proper ventilation contribute to this condi-
Experimentation has shown that, to be success- tion, so proper spacing and pruning can reduce
ful, transplantation should be done in the spring it. Phyllosticta can infect the leaves and the sur-
at the time that new growth commences or soon face of the fruit; it can cause the fruit to crack
after. If many roots are lost, it may be desirable when it expands and destroy it.
to prune the top to bring it into balance with
the remaining roots.
Page 2 ATTRA Pawpaw—A “Tropical” Fruit for Temperate Climates

3. Harvest and with the fruit and its uses. If
you have a cultivar that
Postharvest Handling tastes like banana or
Pawpaws ripen very quickly and bruise easily, mango or cus-
which limits shipping time. Though the fruit tard, tout that
of some cultivars will exhibit a slight color shift in a very visible
from green to yellow, Dr. Pomper’s research way since most
shows that skin color is a poor indicator of ripe- consumers won’t
ness. Pomper claims that the best indicators are have any idea what a
a slight softness when gently squeezed and the good pawpaw tastes like.
ease with which the fruit releases from its stem Because it is so nutri-
when gently pulled. Fruits picked just before tious, nutrition informa-
they are fully ripe, but have begun to soften, will tion might be a good sales
ripen indoors at room temperature or slowly in tool, and can make good poster or black-
a refrigerator. Already ripe fruit will last only 2 board text as long as you don’t overwhelm the
to 4 days at room temperature, but refrigerated reader with too much (shoppers are at stores or NCAT photo by
fruit will last up to 3 weeks. Research is being farmers markets to shop, not read; emphasize the Robyn Metzger.
conducted to determine the effectiveness of using high points: one of the highest protein content
modified-atmosphere shipping and ethylene con- of any fruit; high in potassium, vitamin C, ribo-
trol sachets to extend shelf life (Galli, 2007). flavin, etc.; see www.pawpaw.kysu.edu/pawpaw
/cooking.htm#Nutritional%20Information for
Pawpaws are not suited for certain value-added more detailed nutrition information). Lastly,
products like jams and jellies. Heating pawpaws recipes to take home can be another inducement
changes their flavor, so pawpaws would be best for the consumer to make that first purchase of
used in foods such as ice cream. Recipes using a new food. Go to www.pawpaw.kysu.edu/Recipes
pawpaws are available from several sources, .htm for recipes. The Ohio Pawpaw Growers
including the Kentucky State University website Association (www.ohiopawpaw.com/AboutUs.
(www.pawpaw.kysu.edu/Recipes.htm). html) has many members from around the coun-
Iowa State scientists are researching mechanical try. This organization can also help individuals
pulp extraction and freezing techniques. Because in pawpaw marketing efforts.
cooking destroys important flavor components,
and shelf-life of fresh pawpaws is so limited, such Plant Extracts as
research could be crucial to the commercializa-
tion of the pawpaw (O’Malley, 2010). Anti-carcinogens
and Insecticides
Marketing Dr. Jerry McLaughlin, now retired, of Purdue
University found that pawpaw was a source
Given the fragility and short shelf-life of the
of phytochemicals called acetogenins with
fruit, the uncertain status of processing pawpaw
powerful anti-carcinogenic properties (“Paw-
pulp, as well as the simple novelty of the fruit
paw shows promise in fighting drug resistant
itself, the enterprising pawpaw marketer should
tumors,” 1999). An herbal extract made from
have a good sales plan before hitting stores, res-
pawpaw is on the market. For more information
taurants, or farmers markets. Careful handling,
on pawpaw as an anti-carcinogen go to www.
of course, is a must because the fruit is so eas-
pawpawresearch.com
ily bruised. There are a few commercial-scale
growers in Kentucky and Ohio leading the way, Dr. McLaughlin also isolated a botanical insec-
including one who successfully processed and ticide, asimicin, from pawpaw twigs and bark
sold 1,000 pounds of pulp in 2009 (Ohio Paw- (“Pawpaw those pests,” 1999); however, without
paw Growers Newsletter, 2009). financial backing to shepherd it through the reg-
ulatory process, it is unlikely to be on the mar-
Beyond that, the pawpaw marketer would be
ket anytime soon (Bratsch, 2009).
well-advised to have some printed material
(posters or hand-outs) to acquaint the consumer
www.attra.ncat.org ATTRA Page 3

4. Summary Pawpaw shows promise in fighting drug-resistant tumors.
1997. Purdue News. www.purdue.edu/UNS/html4ever/9709.
Pawpaws may be a viable enterprise for small-scale farmers McLaughlin.pawpaw.html
who can develop a local clientele. However, the amount of
time that must be invested before the first fruit crop (five years Pawpaw those pests. 1999. Organic Gardening. October.
or longer) is a deterrent to many would-be producers. The p. 16
ongoing university research should answer many of these ques-
tions regarding cultivars, culture and processing/marketing. Websites
Kentucky State University Pawpaw Research Project
References www.pawpaw.kysu.edu
Bratsch, Anthony. 2009. Specialty Crop Profile: Paw- Provides information on pawpaw research, guide to growing
paw. Virginia Cooperative Extension. http://pubs.ext. pawpaws, cultivars, suppliers, PawPaw Foundation, and
vt.edu/438/438-105/438-105.html links to other pawpaw Web sites.
Pomper, K.W., D.R. Layne, and R.N. Peterson. 1999. The Purdue University’s facts sheet on pawpaws
pawpaw regional variety trial, p.353-357. In J. Janick (ed). www.hort.purdue.edu/newcrop/cropfactsheets/pawpaw.html
Perspectives on New Crops and New Uses. ASHS Press,
Includes production information and suppliers
Alexandria, VA. www.pawpaw.kysu.edu/PDF/pomper99.pdf
California Rare Fruit Growers’ information on pawpaw
Kentucky State University’s Pawpaw Project
www.crfg.org/pubs/ff/pawpaw.html
147 Atwood Research Facility
Kentucky State University Virginia Cooperative Extension
Frankfort, KY 40601-2355 http://pubs.ext.vt.edu/438/438-105/438-105.html
www.pawpaw.kysu.edu
Ohio Pawpaw Growers’ Association
Callaway, M. B. 1990. The pawpaw (Asimina triloba). Ken- www.ohiopawpaw.com/AboutUs.html
tucky State University Publication CRS-HORTI-90IT. 22 p.
Finneseth, C., S. Kester, R. Geneve, K. Pomper, and D. Plant Sources
Layne. 2000. Propagation of pawpaw (Asimina triloba). Blossom Nursery
Combined Proceedings International Plant Propagator’s Mark and Kathleen Blossom
Society 50:413-416. 216 CR 326
Black, Craig Summers. 2009. America’s Forgotten Fruit. Eureka Springs, AR 72632
The Christian Science Monitor. February 4, 2009. (479) 253-7895
BlossomNursery@gmail.com
Pyle, Katherine. 1992. Picking up pawpaws...and growing www.blossomnursery.com
them, too. California Rare Fruit Growers, Inc. December. p.
Cultivars: Marla, Mitchell, Overleese, Prolific, Sunflower,
24–25, 35–36.
Sweet Alice, Taytwo, Seedlings, Seed. Container and bar-
Galli, F., D.D. Archbold, and K. Pomper. 2007. Pawpaw: eroot (quart or gallon, 8”-18”)
An Old Fruit for New Needs. Acta Horticulturae, 744:641- Nolin River Nut Tree Nursery
666. www.pawpaw.kysu.edu/ppf/Galli2007.pdf John & Lisa Brittain
O’Malley, Patrick. 2010. Pawpaws for the Upper Midwest. 797 Port Wooden Road
www.leopold.iastate.edu/research/marketing_files/ Upton, KY 42784
workshop10/omalley_pawpaw2.pdf (270) 369-8551
john.brittain@windstream.net
Ohio Pawpaw Growers Association Newsletter. 2009. Mar- www.nolinnursery.com
keting pawpaws. Spring. p. 1.
Cultivars: KSU-AtwoodTM, Allegheny, Potomac, Rappahan-
nock, Shenandoah, Susquehanna, Wabash, Davis, Green-
river Belle, IXL, Mitchell, NC-1, Overleese, PA Golden,
Prolific, SAA-Zimmerman, Sue, Sunflower, Taylor, Wells.
Bareroot (1’ – 6’)
Page 4 ATTRA Pawpaw—A “Tropical” Fruit for Temperate Climates

5. Hartmann’s Plant Company J.H. Gordon Nursery
Daniel Hartmann 1385 Campbell Blvd
PO Box 100 Amherst, NY 14228-1403
Lacota, MI 49063-0100 (716) 691-9371
(269) 253-4281 nuttreegordon@hotmail.com
(269) 253-4457 nuttreegordon@att.net
info@hartmannsplantcompany.com www.geocities.com/nuttreegordon/0Kgordon.htm
www.hartmannsplantcompany.com/contact.htm
Cultivars: NC-1, Overleese, PA Golden #1, PA Golden #2,
Seedling. Container (1 gal), and KSU-Atwood TM
PA Golden #3, PA Golden #4, SAA Overleese, SAA Zim-
merman, SAB Overleese, Taytwo, scionwood
Trees of Antiquity (former Sonoma Antique Apple Nursery)
Neil Collins & Thomas Linden One Green World (Formerly Northwoods Retail Nursery)
20 Wellsona Rd. Jim Gilbert, Owner
Paso Robles, CA 93446 28696 South Cramer Rd
(805) 467-9909 Mollala, OR 97038
(805) 467-2509 (877) 353-4028
sales@treesofantiquity.com www.onegreenworld.com
www.treesofantiquity.com
Cultivars: KSU-AtwoodTM, Davis, Mango, Mitchell, NC-1,
Cultivars: Rebecca’s Gold, Sunflower, Wells. Container Overleese, PA Golden, Prolific, Sunflower, Sweet Alice, Tay-
(plastic sleeve, 8-12”) lor, Taytwo, Wells, Wilson, seedlings
"KSU-AtwoodTM" photo courtesy of Kirk Pomper, Ken-
tucky State University.
www.attra.ncat.org ATTRA Page 5

6. Notes
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7. Notes
www.attra.ncat.org ATTRA Page 7

8. Pawpaw—A “Tropical” Fruit for Temperate Climates
By Guy Ames and Lane Greer, NCAT Agriculture Specialists
Published 1999; Revised 2001
Revised 2010 by Guy Ames, NCAT Horticulture Specialist
© NCAT
Tracy Mumma, Editor
Robyn Metzger, Production
This publication is available on the Web at:
www.attra.ncat.org/attra-pub/pawpaw.html
or
www.attra.ncat.org/attra-pub/PDF/pawpaw.pdf
IP373
Slot 34
Version 100410
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