How to grow Pawpaw (American)

Where to plant

Pawpaws grow wild across the eastern half of the country and are hardy in roughly zones 5 to 8. They suit the Mid-South, the Mid-Atlantic, the Midwest and the warmer Northeast, and also grow in the Southern Plains, the Pacific Northwest, the Gulf South, East Texas and North Florida. They need winter chill and a long warm summer, so they do not fruit in Central or South Florida, coastal Southern California, the low desert or Hawaii, and are too tender for the Northern Plains and Alaska. In the Mountain West, try them only in sheltered zone 5 and 6 valleys with regular water.

Choose deep, fertile, well drained, slightly acid soil and avoid heavy or waterlogged ground. Mature trees crop best in full sun. In a sunny spot the tree forms a neat pyramid; in shade it grows leggy and fruits less.

Choosing a variety

Fruit from grafted, named varieties is larger, has fewer seeds and lacks the bitter aftertaste of many wild pawpaws. In Kentucky State University trials, NC-1, Overleese, Potomac, Shenandoah, Sunflower, Susquehanna and Wabash all gave large fruit, and KSU-Atwood and KSU-Benson are newer releases from the same program. Most varieties cannot pollinate themselves, so plant at least two genetically different varieties that flower at the same time. Trees from a single wild patch are usually one clone and cannot pollinate each other.

How to plant

1. Buy container grown trees. Pawpaws have a long, brittle taproot, so bare root and wild dug trees often fail, while container trees transplant well.
2. Plant in early spring, or in late winter in the South. Space trees about 8 to 10 feet (2.5 to 3 m) apart so they can cross pollinate.
3. Dig a hole as deep as the pot and wider, and set the tree at the depth it grew in the pot without disturbing the root ball.
4. Shade young trees under about 2 feet (60 cm) tall for the first year, with a tree shelter or with 30 percent shade cloth held above the tree. Strong sun scorches young leaves.
5. Water in well, mulch and keep grass and weeds well back, as they compete strongly with young trees.

Watering and feeding

Water regularly through the growing season, especially in the first few years and while fruit is swelling in summer. Mulch helps keep the soil evenly moist.

Feed once a year in late winter or early spring with a balanced fertilizer at the label rate. A soil test is the best guide to how much is needed.

Pruning and care through the year

• Flies and beetles pollinate pawpaws, and they are not reliable. For a bigger crop in a small planting, hand pollinate: take pollen from a flower whose anthers are brown and loose and dab it with a small brush onto the sticky green center of a flower from the other variety.
• Do not overdo hand pollination. Too much fruit can break limbs and gives smaller fruit.
• Pawpaw leaves are the only food of zebra swallowtail caterpillars. A few chewed leaves are a sign of a beautiful butterfly, not a problem.

Harvesting

Pawpaws ripen from late August into October. A ripe fruit gives slightly when squeezed gently, like a ripe peach, and smells strongly fruity. Skin color is not a reliable sign, although some varieties turn from dark green to lighter green or yellow. Once a tree starts to ripen, check it every day or two for one to two weeks, and pick fruit as the flesh first softens. Underripe pawpaws can upset the stomach.

Ripe fruit lasts only about three to five days at room temperature, one to three weeks in the fridge, or up to a year as frozen pulp. The skin bruises easily, so handle the fruit gently.

Propagation and saving seed

Named varieties are grafted or chip budded onto seedling rootstocks in spring. Seed can be grown but needs 70 to 120 days of cold, moist stratification in the fridge and must never dry out. Seedlings take 5 to 8 years to fruit and the fruit varies in quality.