Gardeners in Wisconsin and in all of the colder northern areas of the United States can grow many of the tree fruits that can be grown in warmer zones further south, but they must choose varieties carefully. Not all tree fruits will grow in Wisconsin, but a few types have varieties which will grow and thrive in these cold, northern areas. Winter hardiness is the most important factor to consider when choosing which varieties of fruit trees to grow in the north.
Apples (Malus spp.)
The most widely grown fruit tree in the United States, apples are also one of the hardiest types of tree fruit. Varieties exist that are hardy through USDA zone 3, which is in the northernmost part of Wisconsin. The apple varieties Duchess, Lobo and Wealthy are all hardy through USDA zone 3 and can be successfully grown throughout Wisconsin.
Pears (Pyrus spp.)
Pears can be grown in the USDA zone 4 areas in southern Wisconsin, but are not hardy enough to be grown in USDA zone 3 in the north. Choose pear varieties such as Golden Spice, Harrow Delight and Patten. Although the trees themselves are winter hardy, late spring frosts and freezes often kill the buds or flowers, thereby wiping out the current year's crop.
Asian-American Hybrid Plums (Prunus hybrids)
Hybridizers have crossed the hardy American plum species with less hardy Asian species and have developed varieties that resemble Asian plums with winter hardiness. Unlike the elongated American plums, Asian plums are round with a slightly tart flavor. Try the varieties Pipestone, South Dakota or Toka for reliable hardiness through USDA zone 4 in southern Wisconsin.
Sour Cherries (Prunus cerasus var.)
Sour or “pie” cherries can be reliably grown in southern Wisconsin's zone 4 areas. Most pie cherries are not reliably hardy in zone 4, but the varieties North Star, Mesabi and Meteor have shown hardiness there. Sour cherries bloom early in the season and their buds and flowers are susceptible to late spring frosts. Plant against a south-facing wall or another protected location to help protect them from these late season frosts.