Paw Paw Trees

 
 
 Pawpaw (Asimina triloba) 
 
Canada’s only native representative of a tropical plant family.
The Pawpaw (Asimina triloba) is a deciduous, clonal understory tree belonging to the Annonaceae — a family otherwise composed almost entirely of tropical and subtropical genera such as Annona (custard apple, cherimoya, sweetsop) and Cananga (ylang-ylang).
Asimina is the sole temperate genus in this lineage, with A. triloba representing its most northern distribution, extending into southern Ontario.
 
 Morphology & Identification
 
Leaves: Simple, alternate, and obovate to elliptic, ranging 20–30 cm in length. The large leaves create a distinct, tropical appearance, turning golden-yellow in autumn.
Flowers: Perfect, maroon to brownish-purple, 3–5 cm wide, and protogynous (female phase precedes male), reducing self-pollination. They are fly- and beetle-pollinated, emitting a faint, yeasty odor attractive to carrion insects.
Fruit: (5–15 cm long), typically containing several large brown seeds embedded in a soft, custard-like mesocarp. Fruits ripen from late August to October and are the largest edible fruit indigenous to Canada and the United States.
Bark: Smooth and gray-brown with distinct lenticels; inner bark fibrous.
Root System: Pawpaw exhibits clonal growth via root suckering, often forming small colonies genetically identical to the parent tree.
 
 Ecology & Habitat
Native to rich bottomlands, floodplains, and well-drained lower slopes, Pawpaw occurs naturally in deciduous forest understories. It prefers deep, fertile, slightly acidic soils with consistent moisture and partial shade. In more open conditions, it can develop into a small, multi-stemmed tree up to 8 m tall.
Range: Southern Ontario (notably along Lake Erie and Lake Ontario shorelines), extending through the eastern and midwestern United States.
Associations: Often found with Juglans nigra (Black Walnut), Liriodendron tulipifera (Tulip Tree), Carya ovata (Shagbark Hickory), and Acer saccharum (Sugar Maple).
 
Pollination Biology
Asimina triloba requires cross-pollination between genetically distinct individuals to produce viable fruit.
Pollinators are primarily nitidulid beetles and calliphorid flies, which are drawn to the flower’s dark color and faint scent of fermentation.
For successful fruit set, two or more trees should be planted within 3–9 m (10–30 ft) of each other.
Flowers exhibit self-incompatibility, and isolated clones will not bear fruit.
 
 Chemical Ecology
Pawpaw tissues — particularly bark, leaves, and seeds — contain annonaceous acetogenins, including annonacin, which act as natural insecticides and deterrents to herbivory.
While toxic to many insect larvae, these compounds may contribute to Pawpaw’s resistance to pest damage and deer browsing.
 
 Fruit Characteristics & Human Use
The fruit’s custard-like pulp is rich in sugars, protein, and vitamins, with flavor notes resembling banana, mango, and pineapple.
It has long been valued as a traditional food by Indigenous peoples and early settlers.
Due to its soft texture and short shelf life, Pawpaw is best consumed fresh or processed into frozen pulp, preserves, or baked goods.
 
Species Details
Scientific Name: Asimina triloba
Family: Annonaceae
Common Name: Pawpaw
Growth Form: Clonal understory tree
Mature Height: 4–8 m
Zones: 5–8
Light: Full sun to partial shade
Soil: Deep, well-drained loam or sandy loam; rich in organic matter
Moisture: Medium to moist
Bloom Time: April–May
Pollination: Cross-pollinated by beetles and flies
Fruit Ripening: Late August–October
 
Ecological Value
Pollinator Interactions: Early resource for carrion-feeding beetles and flies.
Wildlife Use: Fruits consumed by raccoons, opossums, foxes, and occasionally wild turkeys.
Genetic Note: Naturally clonal, but sexual reproduction is essential for long-term population resilience.
Deer Resistance: Moderate; foliage and bark are unpalatable due to acetogenin compounds.
 Planting Companions
 
Trees: Carya ovata, Juglans nigra, Acer saccharum, Cercis canadensis
Shrubs: Lindera benzoin, Viburnum acerifolium, Hamamelis virginiana
Herbaceous Associates: Asarum canadense, Polygonatum biflorum, Phlox divaricata, Maianthemum racemosum, Woodland Classics Combo
Root Type: Deep, fibrous root system — handle carefully when transplanting
Best Planting Time: Spring through early fall
Maintenance: Minimal; protect young trees from full sun and wind until established
 
Grown from verified Local Guelph seed sources to preserve genetic integrity.
Available for shipping or pickup.
 
 Plant to Protect . Cultivate the Ancient Lineages of the Land.
 
Origin Native Plants — Advancing restoration through native flora.