With historical origins in China, the peach (Prunus persica) spread across the temperate climate regions of the world and developed into hundreds of varieties with delicious fruits. While the system of classifying peaches based on their genetic lines is scientifically useful, for horticultural purposes peaches generally are grouped by their fruit qualities. Grow peaches in full sun garden spots in a moist, well-draining fertile soil in USDA Hardiness Zones 4 through 8.
In 1887, a report by the pomologist Gilbert Onderdonk submitted to the American Commissioner of Agriculture laid out a natural system of classification of peach trees based on genetic origins of trees currently growing in the United States. According to H.P. Gould, author of "Peach-Growing," Onderdonk developed five races of peaches: Peen-to, South China, North China, Spanish and Persian. By examining tree characteristics and fruit qualities, he concluded that all peaches, whether grown from seed or cuttings, made it to the United States from genetic material originating in these five geographic locations. While these genetic lines remain a central classification system of peach trees at a scientific level, the rapid development of new varieties of peaches finds most horticulturists and home-gardeners utilizing a more practical but arbitrary system of classifying by fruit descriptors.
Peaches naturally develop fruits with a fuzzy skin. Some peaches possess branch mutations that produce fruits lacking the peach fuzz and remain smooth and glossy. These smooth peaches are known as nectarines. Botanically, the peach is known as Prunus persica var. persica, while the mutant nectarine is known as Prunus persica var. nucipersica.
The hard stone pit comprising the core of peaches and nectarines either firmly attaches into the nearby flesh or remains independent of the flesh tissue. Stones that tightly integrate into the fruit flesh are called clingstone, while those that readily pull from the core of the fruit without effort or tearing at the flesh are regarded as freestone. Intermediate of these two is the save-all moniker of semi-free.
Two flesh colors dominate discussion of peaches and nectarines. Yellow-flesh describes those fruits with the classic, orange-yellow or gold color flesh, while white-flesh peaches and nectarines produce creamy white to pale yellow flesh. Streaks of red and pink infiltrate the flesh of these fruits from both the skin and the stone pit.
Lastly, peaches and nectarines fall into a seasonal ripening group to help orchard growers and various transportation and marketing industries efficiently create sequential harvesting and sale schedules. Early-season, mid-season and late-season comprise the fruit varieties and varies by month in different climate regions. For example, an early-season ripening peach in Florida may ripen in late March, while the same variety in South Carolina may not ripen until early May.