Difficulty
  pawpaws require minimal effort to manage.
∙ wet climate
Bloom
  mid-late
Ripens
  4+ months
Chill Hours
  400
Pollination
  self-sterile (monoecious)
pH
  5.6 - 7.3
Yield
  3 - 4 years (clone), 5 - 7 years (seedling)
Tolerant
  shade

Native Range and Climate



Pawpaws (Asimina triloba) are native to the United States, east of the prairies, and are generally found in the humid subtropical (Cfa) and hot-summer continental (Dfa) climate.  Only the earliest ripening pawpaws – such as Allegheny, Summer Delight, and Pennsylvania Golden – should be attempted in the warm-summer continental climate (Dfb) further to the north.

Within their native range, pawpaws tend to receive an average of 3" to 5" of rainfall per month throughout the year.  While they have been grown in mediterranean and semi-arid climates, they may require occasional irrigation during spring and summer if you wish to get them to fruit (or even survive).

Young trees (1 or 2 years of age) may require shade or filtered light, since exposure to full sun can damage or kill them.  Mature trees prefer full sun, but they are capable of producing some fruit in heavy shade.


Flowers



Pawpaws can bloom for up to 4 weeks, but each individual flower lasts for ~10 days.  Without hand pollination, fruit set can be low, since bees do not pollinate the flowers, flies and beetles do.  Male and female blossoms may easily overlap in the north, but I have heard of some incompatibility between earlier and later blooming trees in the south.  Unfortunately, there is very little information on varietal bloom times.

The flowers are originally female.  The petals will be partially green and burgundy in color when mature, and they will have a sticky pistil in the center with a bright green, plastic-like appearance behind it (the stamen) that shifts to a light tan color as it ages.  This should last for at least a few days (not sure how long), but then they revert to male and start to produce pollen.  At this stage, the stamen becomes a darker tan color and fluffs up like a lion's mane around the, now obsolete, pistil.


Harvest



Harvest season can last for up to 3 weeks (depending on the variety), and different people may prefer pawpaws in different ripening stages, since it can have a fairly dramatic affect on the flavor.  For the previous two reasons, as well as the available information being quite limited, it is fairly difficult for me to give the many different varieties a proper ripening label.  Regardless, I still have enough information for it to be of some use.


Weight



Common descriptions of some pawpaw varieties often imply that individual fruit generally weigh 227g to 340g+ (1 pound = 16 ounces = 454 grams), but this is somewhat misleading.  Many of these varieties typically produced fruit that weighed 240g or less (sometimes much less), on average, based on trials held at the University of Kentucky and Missouri.  Additionally, the average weight of a pawpaw appears to vary greatly based on the current, or even the previous year's weather, as well as the age of the tree.  Basically, consider the average weight of a variety, including those I give, to be a fairly rough estimate.


Pests and Disease



There are no serious pests or diseases that affect pawpaws, but out of those known to cause some damage, the pawpaw peduncle borer (Talponia plummeriana) is the most significant.  The adult moth is about 6mm in length[1], while the larva is 5mm.[2] Most years, they will thin out the flowers for you as they feed on them[3], but some years, they may destroy enough to ruin the crop.[2] The larva also feed on the roots, twigs, stems, and fruit (primarily around the seed).  Only 1-2 percent of the fruit have been observed to be affected, with no sign of it getting worse as the years progressed.[3] Of those that were affected, only 1-5% of the flesh was damaged.[1]

Pawpaw scionwood with dark channels through the pith might contain pupating larva, which may help spread the moth to other locations.[3]

The asimina webworm moth (Omphalocera munroei) can be a nuisance in some locations, but they aren't a serious threat to anything other than the seedlings.  Their larva primarily feed on leaves, but they may girdle stems as well.

This doesn't really belong in the "pest" category, but caterpillars of the aesthetic Zebra Swallowtail butterfly (Eurytides marcellus) feed exclusively on the leaves from the Asimina genus.  They may cause problems for seedlings as well, but not to the extent of the asimina webworm moth.


Acetogenins



Acetogenins are possible neurotoxins with a link to atypical parkinsonism.  They are present in the entire pawpaw tree, but at a much lower rate within ripe fruit.  Furthermore, some varieties – such as Potomac, Sunflower, and Wabash – have lower concentrations than the others.  There are, however, over 50 different types of acetogenins, and the first correlation made between acetogenins and those who suffered from the affliction were not eating pawpaw, they were eating soursop (a relative of the pawpaw) and drinking a tea made from their leaves.  Acetogenins, or at least some of them, may also have some benefits.  They were demonstrated to be pesticidal, anti-tumor, anti-malarial, anti-viral, and anti-microbial.


Family: Annonaceae



Asimina triloba (pawpaw) is the only species within the entire Annonaceae family that can be grown within the warm-summer humid continental climate (Dfb).  Almost all of the others are either tropical or deeply subtropical.  Some of the pawpaw's best known relatives are the custard apple, cherimoya, soursop, and ylang-ylang, but they belong to another genus.  There are quite a few other Asimina species native to the southeast, one of which grows as far north as Virginia (Asimina parviflora), but there doesn't appear to be much interest in them, at this time.
1. The Pawpaw Peduncle Borer, Talponia plummeriana Busck (Lepidoptera: Tortricidae): A Pest of Pawpaw Fruit, .
2.
3.




Read More

Pawpaw: Asimina triloba

varieties in this section generally share these traits (unless stated otherwise)
The pawpaw peduncle borer is the only pest that is occasionally an issue, but most years, the damage is light.  As for disease, there are none of any significance.  Pawpaws are often said to be hardy down to zone 5a, but there is some evidence that many of them can handle temperatures down to zone 4a, at least when they are established.  Regardless, they require a fairly long grow season to ripen the fruit (at least 4 months from bloom), and only the earliest ripening varieties should be attempted near their northern limit.  Pawpaws require minimal effort to manage, but they are best grown in a climate that is relatively wet.  They also bloom quite late, which helps them avoid frost damage.

Allegheny

🔍
Zone
• 4
Ripens
🥑
• early
Fruit
• 125g at KSU, 8% seed

Allegheny can produce an overabundance of small fruit, which can be avoided with fruit thinning (thinning is unnecessary for most pawpaw varieties).

Cantaloupe

🔍
Discovered in Richmond, Kentucky.
Zone
• 5a (4)
Ripens
🥑
• early-mid?     ◦ later than Honey Dew and Marshmallow.
Fruit
• ~300g, freestone

Halvin

🔍
Discovered in southwestern Iowa near the city of Bedford.
Zone
• 5a (4)
Ripens
🥑
• mid     ◦ 2 to 3 weeks after Shenandoah
Fruit
• large, 227g+

The description of one nursery claims that Halvin ripens very early, but the only report I have seen on it was quite contradicting.

Honey Dew

🔍
Discovered in Richmond, Kentucky.
Zone
• 5a (4)
Ripens
🥑
• early-mid?     ◦ somewhere between Marshmallow and Cantaloupe.
Fruit
• ~275g, freestone

Kentucky Champion

🔍
Zone
• 5a (4)
Blooms
💮
•    ◦ may benefit from having another early ripening variety for pollination
Ripens
🥑
• early?
Color
• yellow-orange flesh
Growth
• vigorous
Fruit
• large, possibly an average of 230g with 8% being seed
Yield
• moderately productive

KSU Atwood

🔍
Originated in Maryland, introduced in Kentucky (2009).
Zone
• 5a (4)
Ripens
🥑
• early-mid?
Fruit
• 120g at KSU, 8% seed
Yield
• highly productive

Atwood may be one of the most productive varieties.

KSU Benson

🔍
Zone
• 5a (4)
Ripens
🥑
• early-mid?
Fruit
• fairly round in shape
Yield
• highly productive

KSU-Benson is mentioned for being an "early season ripening variety", but it gives me no details for a proper comparison.

Mango

🔍
Selected from the wild in Tifton, Georgia (1970).
Zone
• 5a (4)
Blooms
💮
• late
Ripens
🥑
• early-mid     ◦ 1 to 1.5 weeks after Shenandoah
Fruit
• mushy

Mango has a relatively mushy texture some people tend to not like, but the flavor is generally considered to be good.  It currently appears to be the fastest growing tree out of all the named varieties (Potomac and Nyomi's Delicious may rival it).  There is not much out there about the average weight of its fruit or the productivity of the tree, but based on what I have seen, I'd say that it's around 150g with at least average productivity. 

Pawpaws are considered to have tropical-like flavors, with mango occasionally being one of them (according to others), but the 'Mango' variety doesn't appear to have much of a mango flavor, if it does at all, so its name is quite deceiving.

Maria's Joy

🔍
Davis x Prolific.  Developed in Indiana.
Zone
• 5a (4)
Fruit
• large, 227g+

Marshmallow

🔍
Discovered in Richmond, Kentucky.
Zone
• 5a (4)
Ripens
🥑
• early-mid?     ◦ earlier than Cantaloupe and Honey Dew.
Fruit
• ~250g, seeds may be around 7% of the weight, freestone
Yield
• highly productive

Marshmallow is the sweetest of the three freestone varieties (the others being Cantaloupe and Honey Dew).

NC-1

🔍
Davis x Overleese.  Ontario, Canada (1976).
Zone
• 5a (4)
Ripens
🥑
• early-mid?
Fruit
• 180g at KSU
Yield
• below average production

NC-1 ripens during the 3rd week of September in Ontario and the 4th week of September in Northern Illinois. 

high acetogenin content

Overleese

🔍
Selected from the wild in Rushville, Indiana (1950).
Zone
• 5a (4)
Ripens
🥑
• early-mid? (mid)
Fruit
• 170g at KSU
Yield
• appears to be a light producer most years

Overleese has a milder flavor than most other varieties.  This attribute is often desired since some people do not care for the strong flavor offered by the others. 

high acetogenin content

Pennsylvania Golden

🔍
Seed originated in Amherst, New York.
Zone
• 4
Ripens
🥑
• early
Fruit
• 110g at KSU, 8% seed

While PA Golden appears to be quite productive due to the exceedingly large number of fruit it produces, it may have a low pulp to skin ratio, meaning its true productivity (total flesh weight) could be quite average. 

Fruit thinning may greatly benefit PA Golden.

Potomac

🔍
Developed in Boyce, Virginia.
Alias
• 4-2
Zone
• 5a (4)
Ripens
🥑
• mid? (mid-late)     ◦ slightly later than Susquehanna?
• precocious?
Fruit
• 235g at KSU, 4% seed
Afflictions
• Somewhat susceptible to cracking.

Potomac is more upright, less spreading, and supposedly grows faster than most others. 

low acetogenin content

Prolific

🔍
Selected (from the wild?) in Bellevue, Michigan (mid 1980's).
Zone
• 5a (4)

Some pawpaw varieties can have a bitter aftertaste, and Prolific appears to be one of the worst offenders.

Rappahannock

🔍
Developed in Boyce, Virginia.  Patented in 2004.
Alias
• 8-58
Zone
• 5a (4)
Ripens
🥑
• mid
Color
• green-yellow skin
Fruit
• 95g at KSU, 6% seed
Yield
• moderately productive

Rappahannock is fairly unique in that its leaves are held in a horizontal fashion and its fruit may display a more yellowish color when they start to ripen.

Rebecca's Gold

🔍
Originated in Bellevue, Michigan (1974).
Zone
• 5a (4)
Ripens
🥑
• very late

Rebecca's Gold has a fairly poor reputation when it comes to flavor.  The term "watered down" is sometimes used.

Shenandoah

🔍
A seedling of Overleese.  Originated in Maryland.
Alias
• 1-7-1
Zone
• 4
Ripens
🥑
• early-mid?     ◦ roughly 0 to 1.5 weeks before Overleese
• precocious
Fruit
• 150g at KSU, 7% seed
Yield
• at least moderately productive

Shenandoah is considered to have a mild flavor for a pawpaw, much like its parent "Overleese", which some people seem to prefer.  Shenandoah is more productive than Overleese.

Summer Delight

🔍
Overleese x Sunflower?
Zone
• 5a (4)
Ripens
🥑
• very early     ◦ late July to early August in Kentucky.
• around 3.5 to 4 months to ripen after bloom.

Summer Delight may be the earliest ripening Pawpaw variety, but the tree could take 4-5 years to fruit.  3-4 years is about average within its native range.  Some take 6+ years in colder or drier climates.

Sunflower

🔍
Selected from the wild in Chanute, Kansas (1970).
Zone
• 5a (4)
Ripens
🥑
• mid-late?
Fruit
• 155g at KSU
Yield
• at least moderately productive

Sunflower is somewhat prone to having a bitter aftertaste, but it may only be detectable in some fruit and vary in significance by year.  In spite of this, it is still considered to have good flavor. 

Nurseries often mention Sunflower for being self-fertile, but I have not seen anyone personally confirm this, which makes me quite suspicious considering how common it is. 

low acetogenin content

Susquehanna

🔍
Developed in Boyce, Virginia.  Patented 2004.
Alias
• 11-5
Zone
• 5a (4)
Blooms
💮
• mid-late?
Ripens
🥑
• mid? (mid-late)     ◦ roughly 3 weeks after Shenandoah?
• after Wabash
Fruit
• 185g at KSU (200g+ elsewhere), 4% seed
• firmer than a ripe avocado
• firmer than most varieties (if not all)
Yield
• lightly productive

high acetogenin content

Tropical Treat

🔍
Selected from the wild in Kentucky (2010).
Zone
• 5a (4)
Color
• green-yellow skin
Fruit
• 180g+, up to 6" long
Yield
• at least moderately productive

Wabash

🔍
Developed in Boyce, Virginia.
Alias
• 1-7-2
Zone
• 5a (4)
Ripens
🥑
• mid     ◦ before Susquehanna
Color
• yellow-orange flesh
Fruit
• 185g at KSU
Yield
• at least moderately productive
Afflictions
• Somewhat susceptible to cracking.

low acetogenin content

Wells

🔍
Selected from the wild in Salem, Indiana (1990).
Zone
• 5a (4)
Blooms
💮
• mid-late? (late)
Ripens
🥑
• mid-late?
Fruit
• 105g at KSU, 128g elsewhere
Yield
• low to moderate production, possibly depending on location

low acetogenin content