Pawpaws add garden interest
Looking to add a touch of the tropics to your yard or garden? Though not a palm tree or other iconic plant species of the tropics, the pawpaw (Asimina triloba) is a small, native tree belonging to a family of tropical and sub-tropical fruiting species including the guana, banana, or soursop.
It is the only species in the group that grows in a temperate climate with a range over most of Eastern North America from Ontario and Michigan and south to Florida and Texas, including Pennsylvania.
The tree provides edible landscaping in the form of unusual greenish-yellow fruit comparable to bananas, mangos, or pineapple in flavor.
Pawpaws are understory trees or shrubs growing to 10 to 12 feet in height but can attain heights of 25 feet in areas where optimal conditions are found. They acquire a more open structure if planted under tall, open trees such as oaks, maple, or hickory or in partial shade, but the fruit can develop best in sunny sited locations.
Pawpaws will also spread through suckering creating a “pawpaw patch.”
To maintain the tree form, clip suckers as they form.
Pawpaws prefer moist, slightly acidic soils and require regular watering as seedlings. They do not perform well in poorly drained soils. Seedlings may be transplanted but older, larger plants do not like to be transplanted due to the development of a large tap root as they grow. After the first two years, the trees require little care or maintenance.
The large elliptical leaves are aromatic, with a smell reminiscent of bell pepper.
They retain their green color well into the fall when they turn a bright yellow.
Chemicals in the twigs and branches have insecticidal properties. As a result, they are relatively pest free and deer do not browse on the twigs, foliage or fruit, though birds and other wildlife (raccoons, opossums, squirrels) will eagerly feed on the ripe fruit.
Flowers bloom in April or May before the leaves appear. Each flower is cup-shaped and green when they open but become dark red-purple as they mature. At least two plants are needed for cross-pollination.
Natural pollinators of pawpaw are flies and beetles. While pawpaw is the host plant for the zebra swallowtail butterfly (Eurytides marcellus), the range for this butterfly does not include Butler County.
Large, yellow-green mango-shaped fruits appear after five to seven years. Fruits ripen between August and September. Each fruit can weigh from five to 16 ounces.
Fruits have a thin skin and consist of a creamy yellow flesh that is smooth like custard, giving it another common name: custard apple.
Once ripe, pawpaws only last a few days. They can be refrigerated for a week if not quite ripe. The fruit may develop dark spots that are indicative of a fungus. However, the spots do not affect the fruit edibility. The fruit are easy to eat as well, simply cut in half and scoop out the flesh with a spoon. The large seeds are easy to remove.
Pawpaws can be used as a substitute for bananas in banana bread or made into pies, ice cream, or sorbet.
Pawpaws are available from nurseries as bare-root and container-grown trees.
Seeds can be sown in the fall to over-winter or can be stratified by exposing to cold temperature (32 degrees to 40 degrees) for 90 to 120 days. Seeds should be kept moist throughout stratification. If sowing seeds into containers, use deep pots or tubes to allow for healthy roots. Several cultivars are available including a dwarf variety.
Festivals celebrating this forgotten native fruit have become annual events in York County, Pa., Ohio and West Virginia. Look for these festivals in 2022. Invest in a pawpaw tree and give your garden a touch of the tropics.
Penn State Extension has additional information about growing pawpaws https://extension.psu.edu/the-native-pawpaw-tree) and cooking with pawpaws, or https://extension.psu.edu/pawpaw-fruit-in-the-garden-and-the-kitchen. If you have questions about pawpaws, call the Butler County Master Gardener Garden Hotline at 724-287 4761, ext. 7 or email the Master Gardeners at butlermg@psu.edu.
Mary Alice Koeneke is a Penn State Extension Master Gardeners of Butler County.