Q: I saw what looked like an orange tree with thorns growing in my woods. Are there hardy orange trees that will survive here?
Answer: The trifoliate orange (Poncirus trifoliata) has naturalized as far north as Cape Cod and as far west as St. Louis, Mo. Native to China, the trifoliate orange, also referred to as the hardy orange, was brought to the United States before the 1860s. It is one of the first plants that was widely planted by William Saunders, the first landscape gardener hired by the U.S. Dept. of Agriculture. In the 1890s trifoliate orange was used in the USDA breeding program in search of hardier oranges, grapefruits, mandarins and kumquats. As a result, there are hundreds of hybrids between trifoliate orange and every kind of citrus. Unfortunately, the bitter and off-flavors found in trifoliate orange overpower most of the fruit from resulting hybrids. The tree will survive to 0 degrees Fahrenheit and is deciduous, which means it loses its leaves in the winter. The fragrant blossoms open in the spring. The tree will reach a height of 8 to 20 feet and spread from 6 to 15 feet wide. It has long sharp thorns up and down the stems. For this reason, it can be used as a living fence and impenetrable hedge.
It produces small orange fruits with many seeds. The fruit is edible, although bitter with off-flavors that linger. Birds and other animals will eat the fruit and spread the seeds across the landscape. Two interesting cultivars are English Large, which has larger blossoms; and Flying Dragon, which is a showy contorted tree. There are enthusiasts across the Southeast who gather each year to learn about hardy citrus. The Southeastern Citrus Expo is coming up later this month in Bolivia, N.C. For more information. visit the Facebook page for Southeastern Citrus Expo.
Q: When is the best time to plant fruit trees?
Answer: The best planting time in North Carolina is late fall or early winter. The roots will then be able to grow through the winter, resulting in greater tree growth during the first season, which ultimately leads to larger trees. Young fruit trees are commonly shipped “bare root” with the exposed roots wrapped in moist sawdust. Plant the trees as soon as possible after purchase.