Asimina triloba, Pawpaw
Zone
5a (4b)
Pollination
self-sterile (monoecious)
Blooms
(overall) late
Ripens
4+ months
Chill Hours
400
pH
5.6 - 7.3
Yield
3 - 4 years (clone), 5 - 7 years ( seedling)
Tolerant
shade

Pawpaws are native to eastern United States, an area that receives 3" to 5" of rainfall per month throughout the year. They have been grown in mediterranean and semi-arid climates, but 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.

Pawpaws can bloom for up to 4 weeks, but without hand pollination, fruit set can be low because bees do not pollinate the flowers, flies and beetles do. The flowers are originally female and will have a sticky green center in this stage. This should last for at least a few days (not sure how long), but then they revert to male and start to produce pollen. Bloom may easily overlap in the north, but I have heard of some incompatibility between earlier and later blooming trees in the south.

Harvest season can last for up to 3 weeks, 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 lack of information, it is fairly difficult for me to give the many different cultivars a proper ripening label. Regardless, I still have enough information for it to be of some use.

Common descriptions of some pawpaw cultivars often imply they produce fruit that weigh 227g to 340g or more (1 pound = 16 ounces = 454 grams), but this appears to be incorrect. Many of these cultivars typically weighed 240g or less on average (sometimes much less) based on trials held at the University of Kentucky and Missouri. Also, 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 pawpaws, including those I give, to be a pretty rough estimate.

Acetogenins are potential neurotoxins with a possible link to atypical parkinsonism. They are present in the entire pawpaw tree, but at a much lower rate within ripe fruit. Some cultivars have lower concentrations within their fruit as well. 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 to pawpaw), and drinking 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.

Asimina triloba (pawpaw) is the only species within the entire Annonaceae family that can be grown in a cold continental climate. Almost all of the rest are either tropical or deeply subtropical. Some of its best known relatives are custard apple, cherimoya, soursop, and ylang-ylang, but they belong to another genus (family > genus > species). There are quite a few other Asimina species native to southeastern United States, one of which grows are far north as Virginia (Asimina parviflora), but there doesn't appear to be much interest in them at this time.




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Pawpaw
Asimina triloba

Allegheny

buy
Zone
:
5a
Ripens
:
early

Allegheny is known for producing an overabundance of small fruit which, although not required, can be avoided with fruit thinning (I imagine it's similar to Pennsylvania Golden). The fruit weighed an average of 125g at KSU with the seeds making up 8% of its weight.

Davis

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Selected from the wild in Michigan 1959.
Zone
:
5a
Ripens
:
mid?
Size
:
up to 5" fruit

The two Davis pawpaw trees at the Carandale Farm in Oregon, WI (Zone 5a) grew slowly for 5 years before taking off (they were reported to be over 10ft after 9 years). It took 6 years for them to bloom. This is substantially better than what their two Pennsylvania Golden trees had done at their test site. Not much else is known about Davis, it is rarely mentioned.

Halvin

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Found in southwestern Iowa near the city of Bedford.
Zone
:
5a
Ripens
:
mid-late?

Halvin produces large fruit with an average weight of 227g to 397g (probably much closer to the lower end).

Sometimes mentioned for ripening very early, but I have seen some highly contradicting information.

Kentucky Champion

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Zone
:
5a
Ripens
:
early-mid?

Kentucky Champion is supposedly a good choice for cool summer climates, but I have not seen anyone personally confirm this. It is mentioned for being self-fertile, but at this time, I really doubt it. Produces large pawpaws that "supposedly" weigh an average of 230g, although the seeds make up roughly 8% of its weight.

KSU-Atwood

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Seedling from Maryland, released in 2009 by the Kentucky State University.
Zone
:
5a
Ripens
:
early-mid?

KSU-Atwood weighed an average of 120g per fruit at KSU, 8% of which comes from the seeds. Atwood may be one of the most productive cultivars.

KSU-Benson

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Zone
:
5a
Ripens
:
early-mid?

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

Mango

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Selected from the wild in Tifton, Georgia 1970.
Zone
:
5a
Blooms
:
late
Ripens
:
mid

Mango has a mushier texture some people tend to not like, but the flavor is generally considered to be quite good. It currently appears to be the fastest growing cultivar, but I don't think it's precocious as well. 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 being one of them, but the "Mango" cultivar doesn't sound like it has much of a mango flavor, if at all, so its name is quite deceiving.

Maria's Joy

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Davis X Prolific. Originated in Indiana.
Zone
:
5a

Maria's Joy has one of the best reputations when it comes to flavor. The fruits are large, supposedly averaging around 227g to 397g (probably near the lower range).

Middletown

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Selected from the wild in Middletown, Ohio 1915.
Zone
:
5a
Blooms
:
mid-late? (late)
Ripens
:
mid-late?

Middletown produces very small pawpaws that weighed an average of 75g per fruit at KSU. Productivity by total weight per tree is very low.

Mitchell

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Selected from the wild in Jefferson County, Illinois 1979.
Zone
:
5a
Ripens
:
early? (possibly much later)

Mitchell is one of the least productive cultivars. The fruit weighed an average of 115g at KSU, and the seeds consisted of 13% of the weight. In one trial, Mitchell had an average of 1.9 fruit per cluster, making it the lowest out of all 28 that were tested (the mean was 2.6 and the highest named cultivar was Wilson with 3.1 fruit per cluster).

high acetogenin content

NC-1

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Davis x Overleese. Ontario, Canada 1976.
Zone
:
5a
Ripens
:
early-mid? (early)

NC-1 ripens during the 3rd week of September in Ontario and the 4th week of September in Northern Illinois, right next to Lake Michigan (where summers are much cooler), making it a promising cultivar for northern growers, but it is one of the less productive cultivars (with fruit weighing an average of 180g at KSU), although, I have seen a couple of people praise it for having good flavor.

high acetogenin content

Overleese

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Selected from the wild in Rushville, Indiana 1950.
Zone
:
5a
Ripens
:
mid?

Overleese has a milder flavor than most other pawpaws. This attribute is often desirable since some people do not care for the strong flavor offered by the others. It is one of the parent trees of other popular cultivars like Shenandoah and NC-1. The fruit weighed an average of 170g at KSU, and the tree appears to be a light producer most years.

high acetogenin content

Pennsylvania Golden

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The seed originated from a tree in Amherst, New York.
Zone
:
5a
Ripens
:
early

PA Golden is often recommended for cool summer climates due to its early ripening habit.

Appears to be one of the most productive cultivars, even when considering the low weight of its fruit (an average of 110g at KSU with 8% being seed). This essentially means the fruit count is very high - roughly 2 to 4 times more than the other 7 cultivars tested - according to one trial. The same trial also indicated that its pulp percentage is much lower than most of the other 7 cultivars, and if correct (based on only 1 year of research), its true productivity is actually quite average.

The most negative thing I have seen about PA Golden is that after 9 years at the Carandale Farm in Oregon, WI (Zone 5a), their 2 PA Goldens were only 6ft tall and still hadn't bloomed. Davis was the only other cultivar tested there, and they were doing much better at the time, although, it still took them longer than usual to bloom (6 years). Keep in mind, this is only at one test site and the sample size was quite small.

Potomac

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A seedling from the Blandy Experimental Farm in Boyce, Virginia. 4-2
Zone
:
5a
Afflictions
:
Somewhat susceptible to cracking

The fruit of Potomac weighed an average of 235g at KSU, and the seeds made up only 4% of its weight. The tree is more upright, less spreading, and (supposedly) grows faster than most others.

low acetogenin content, possibly precocious

Prolific

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

Prolific currently has the worst reputation when it comes to having a bitter aftertaste (a problem that sometimes plague the pawpaw). The details on this are lacking, so I am not implying all of the fruit will have a bitter aftertaste or that some of its fruit will have it every year. Prolific is often used as a parent tree and has helped produce a few great cultivars, such as Maria's Joy. Overall, no one seems to recommend this cultivar, but some do imply that you should avoid it.

Rappahannock

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A seedling from the Blandy Experimental Farm in Boyce, Virginia. Patented in 2004. 8-58
Zone
:
5a
Ripens
:
early-mid?

Rappahannock is unique in that its leaves are held in a horizontal fashion and its fruit may display a more yellowish color when they start to turn ripe. The fruit weighed an average of 95g at KSU with the seeds making up 6% of the weight. This makes it one of the smallest, but overall productivity by total weight is probably around average. The flavor of Rappahannock is somewhat mysterious since the cultivar isn't mentioned very often, and those that I have seen are somewhat inconsistent. I'd say that at worst, it has an average pawpaw flavor for an improved cultivar (better than most seedlings), so it's a fairly safe tree to get.

Rebecca's Gold

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Originated in Bellevue, Michigan 1974.
Zone
:
5a
Ripens
:
very late

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

Shenandoah

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A seedling of Overleese. Maryland. 1-7-1
Zone
:
5a
Ripens
:
early-mid? (mid)

Shenandoah is considered to have a mild flavor for a pawpaw, much like its parent "Overleese", yet it is still highly recommended. Shenandoah is more productive than Overleese (and many other cultivars) with fruit weighing an average of 150g at KSU, 7% of which is seed. Shenandoah ripens roughly 0 to 1.5 weeks earlier than Overleese.

Fruits over a long period of time, and can produce flowers during the 2nd year.

Summer Delight

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Zone
:
5a
Ripens
:
very early

Summer Delight is probably the earliest ripening Pawpaw cultivar, but the tree may take 4-5 years to fruit (3-4 years is about average).

Sunflower

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Selected from the wild in Chanute, Kansas 1970.
Zone
:
5a
Ripens
:
mid-late?

Sunflower is more prone to having a bitter aftertaste, but those who talk about it do imply only some of the fruit have this problem and that some years are better than others. In spite of the occasional issue with bitterness, 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 popular it is. The fruit weighed an average of 155g at KSU, and the tree leans on the more productive side.

long harvest season, low acetogenin content

Susquehanna

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A seedling from the Blandy Experimental Farm in Boyce, Virginia. Patented 2004. 11-5
Zone
:
5a
Blooms
:
mid-late?
Ripens
:
late

Susquehanna produces fairly large fruit, weighing an average of 185g at KSU, but based on other trials, it can easily obtain over 200 grams. In addition, only a small amount of its weight consists of seed (4%). On the negative side, its overall productivity by weight may be one of the lowest.

high acetogenin content

Tropical Treat

buy
Selected from the wild in Kentucky 2010.
Zone
:
5a
Ripens
:
early-mid?
Size
:
up to 6" fruit

The weight of the fruit may be on the larger side, but there is no real estimated average.

Wabash

buy
A seedling from the Blandy Experimental Farm in Boyce, Virginia. 1-7-2
Zone
:
5a
Ripens
:
mid-late?
Color
:
yellow-orange flesh
Afflictions
:
Somewhat susceptible to cracking

Wabash weighed an average of 185g per fruit at KSU, and is one of the more productive cultivars.

low acetogenin content

Wells

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Selected from the wild in Salem, Indiana 1990.
Zone
:
5a
Blooms
:
mid-late? (late)
Ripens
:
mid-late?

Wells weighed an average of 105g per fruit at KSU; other trials have it around 128g per fruit. Productivity ranges from very low to average, probably depending on location and year.

low acetogenin content

Wilson

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Selected from the wild in Harlan County, Kentucky 1985.
Zone
:
5a

Wilson weighed an average of 90g per fruit at KSU and is at least moderately productive. In one trial, Wilson had and average of 3.1 fruit per cluster, making it the 2nd highest. Out of the 28 that were tested, the mean was 2.6 fruit per cluster. The highest was achieved by "11-13", an unreleased cultivar, with an average of 3.7 fruit per cluster. The lowest was achieved by Mitchell and Wabash with an average of 1.9 and 2.0 fruit per cluster, respectively.

Wilson was the only cultivar to have a survival rate of 100% at the Corvallis, Oregon Regional Trials after the first 6 years had passed. Some unknown affliction, referred to as the blue stain disease, ravaged most other grafted cultivars, killing 25% of them after 4 years and 50% after 6 years. 76 seedlings were also planted, but only 7.9% were dead after 5 years and 18.4% after 6 years. Excluding unreleased cultivars with no commercial name (that I am aware of), Mitchell, Taylor, and Wabash (1-7-2) were the 2nd most resistant with a survival rate of 75%. PA Golden and Rappahannock (8-58) had a survival rate of 62.5%, and NC-1, Sunflower, Susquehanna (11-5), and Potomac (4-2) had 50% remaining. Middletown, Wells, Overleese, Taytwo, and Shenandoah (1-7-1) performed even worse. Wilson could be used to develop resistant cultivars against the affliction, whether it is environmental or some kind of infectious disease, however, this event happened over a decade ago, and I have not heard of any significant complaints since then. One nursery in Oregon does mention that it's likely the result of trauma or stress unrelated to micro-organisms. Considering that the Pacific Northwest has very dry summers, and pawpaws are adapted to high rainfall, this implies that it's probably environmental.