Part 3
WILD PLANTING EXPERIMENTS
BASELINE DOCUMENTATION
Pawpaw Patch along the Saline River of southern Michigan
PURPOSE: Photos and text of the SALINE RIVER wild patch are intended for learning pawpaw habitat preferences.
Later sections of this page will explore possibilities for wild planting in locations where pawpaw could thrive but are missing.

ABOVE: Pawpaw has a taproot, so it cannot grow in the lowest flood zone of a river. Connie Barlow is touching stems of the portion of the pawpaw patch closest to the Saline River, which is growing on the first rise. (December 2020)

ABOVE: A bit downstream from the previous photo, these two pawpaw stems are on the first rise barely above this very high flood stage. All green leaves in the foreground are pawpaw leaves. Pawpaw stems can grow very close together because, technically, they are the same individual tree. The photo below shows why. (September 2021)
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ABOVE: Pawpaw "patches" are formed primarily from vegetative stems (not roots) that grow horizontally just below the surface, and then send up a new vertical stem some small or moderate distance away. Apparently, the horizontal stems cannot grow through even small depressions that periodically flood. (December 2020)

ABOVE and BELOW: The vertical stems themselves live for no more than about 50 or 60 years and usually lean quite a bit out of the vertical. Even so, the patch as a whole can be centuries old (May 2021).


ABOVE and BELOW: Pawpaw annually regrows its large leaves, such that spring ephemerals find excellent and long-lasting habitat. (May 2021)


ABOVE: By the beginning of autumn, when the fruits begin to ripen, late-season ephemerals, such as nettles, have taken the place of the spring ephemerals. (24 September 2021)

ABOVE: Because this family of plants (Annonaceae) evolved many of its species long ago, pawpaw forged a relationship primarily with mammals large enough to swallow the big seeds whole along with the pulp. Passage through the animal's digestive system was not only a great way to achieve potentially long-distance seed dispersal, but a lump of fertilizer was an additional gift wherever the seeds were deposited. For the past 10,000 years bears and humans have become the primary seed dispersers.
In order to ensure safe passage through an animal, the seeds must fully mature and harden before the pulp does. Even if an unripe fruit falls early, animals tend to leave it alone: the skin and pulp remain unpalatable until fully ripe. Even insects avoid unripe fruit. As well, the seeds are and remain exceedingly poisonous to all mammals thus ensuring that rodents will not disturb them.
Poisonous seeds and thin, fragile skin easily bruised, as well as brown signifying a well-ripened fruit, means that this fruit still hasn't been turned into a commercial food. People do plant pawpaw orchards, but more for their own consumption and as a U-pick seasonal endeavor. (24 September 2021)

ABOVE: Experiencing an old-growth pawpaw patch (an ongoing mixture of old and new stems) is like nothing else in this region. Annonaceae is a huge family of tropical and subtropical plants, often with very large fruits (e.g., Cherimoya). No other species in that family extends as far poleward beyond the tropics as does Asimen on Turtle Island.

ABOVE: Connie Barlow filmed and posted a 36-minute video that shows this patch (in great detail) along the Saline River primarily during the fruiting season.
VIDEO: Helping Forests Walk 04 B - Is this an Old Growth Pawpaw Patch? (Michigan, 2021)
Learning about Germination
BASIC INFORMATION BY KENTUCKY STATE UNIVERSITY:
Another way is to stratify the seed in the refrigerator (32 to 40 degrees F). In this case the cleaned seed should be stored in a plastic ziplock bag with a little moist sphagnum moss to keep the seed moist and suppress fungal and bacterial growth. After stratification the seed should be sown 1 inch (2.5 cm) deep in a well-aerated soil mix, pH 5.5 to 7, with an optimum temperature of 75 to 85 degrees F. Use tall containers, such as tree pots or root trainers, to accommodate the long taproot. The seed will normally germinate in 2 to 3 weeks, and the shoot will emerge in about 2 months. Germination is hypogeal: the shoot emerges without any cotyledons. For the first two years, growth is slow as the root system establishes itself, but thereafter it accelerates. Trees normally begin to bear fruit when the saplings reach 6 feet, which usually requires five to eight years.

ABOVE: Connie's husband, MICHAEL DOWD, assisted with digging winter stratification pits in November 2021 and 2022 in the same area along the Huron River (Ypsilanti) where germinated seeds would be planted in later years. This photo was taken in 2022, as he pours seeds collected at Marc Boone's orchard into a winter stratification pit. (Eleven months later, he died suddenly two days after attending his father's hospice death in upstate New York.)
IMPORTANT DISCOVERIES: In late May 2023, after digging up the 2022 seeds from winter stratification, Connie put some in the refrigerator and removed them at monthly intervals to watch for germination success and timing. Overall, I learned:
• Germination can be delayed by refrigeration, without reducing germination success.
• Seeds put into room temperature soil conditions will begin to germinate in about 7 days at the earliest. All viable seeds will have germinated within just 4 weeks. I kept some ungerminated seeds continuing in the kitchen for the whole summer, and just 1 germinated after 2 months.

ABOVE LEFT: Rarely, a seed that did not germinate felt squeezable. I opened one and found worms of some type inside.
ABOVE RIGHT: I laid the seeds horizontally on top of soil in several containers in the kitchen, covered them with paper towel, and kept the top moist. This way I could see germination without having to dig. And that is why in this photo the roots all orient in the same way.
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