Most commercially grown peach trees are indeed grafted, a practice that joins two different plant parts to create a single, functioning tree. This technique combines a desired fruit variety with a specially selected root system, fundamentally optimizing the tree for production and survival. Grafting allows growers to bypass the genetic uncertainty that comes with planting a peach pit, ensuring the resulting tree yields a predictable, high-quality fruit. This horticultural fusion is a standard procedure in nurseries before the trees are sold to consumers or commercial orchards.
The Necessity of Grafting
Grafting allows for the preservation of desirable traits, directly addressing the issue of genetic consistency in fruit production. A peach grown from seed, even from a high-quality fruit, will produce a tree with genetically mixed characteristics, often resulting in fruit that is smaller, less flavorful, or otherwise different from the parent. By grafting, a cutting from a proven cultivar, such as ‘Elberta’ or ‘Redhaven’, is attached to a separate root system, guaranteeing the new tree will yield fruit identical to the source tree.
Grafting also provides control over the tree’s final size and time until harvest. Specific rootstocks manage the tree’s vigor, promoting faster development and earlier fruit bearing, sometimes within the third year after planting. Rootstocks influence the overall canopy size and structure, which helps growers manage the trees more efficiently with less labor.
Grafting is also used to adapt the tree to adverse local soil conditions and pathogens. Growers select rootstocks specifically for resistance to common soil-borne diseases, such as the root-knot nematode. Rootstocks like ‘Nemaguard’ are widely used in sandy soils where nematodes are prevalent, while others may offer better tolerance to cold temperatures or poorly draining soil.
Understanding the Components
The grafted peach tree is composed of two distinct botanical parts. The top section, known as the scion, is the portion of the stem or bud taken from the desired fruit variety. This scion determines all the above-ground characteristics, including the type and quality of the peach, the shape of the canopy, and the color of the flowers.
The lower section, called the rootstock, is the established root system onto which the scion is grafted. This part dictates the tree’s foundational characteristics, such as its tolerance to drought, its ability to anchor firmly in the soil, and its resistance to specific soil pathogens. Common rootstocks used in peach production include ‘Lovell’ and ‘Nemaguard’, which are chosen for their desirable root traits.
‘Lovell’ is generally favored for its tolerance of heavier, wetter soils and its cold hardiness, though it is susceptible to certain nematodes in sandy soil. ‘Nemaguard’ is highly valued for its strong resistance to the most destructive root-knot nematodes, though it can be sensitive to root waterlogging.
Practical Care and the Graft Union
The point where the scion and the rootstock meet is called the graft union, and it appears as a slight bulge, knob, or noticeable line on the trunk of the tree. This area is usually located a few inches above the soil line on a nursery-bought tree.
When planting, it is essential to keep this graft union well above the surrounding soil surface. If the scion wood is buried, it may develop its own roots, a process called scion rooting. This negates the specific benefits provided by the chosen rootstock, such as disease resistance or size control, potentially leading to a much larger or less resilient tree.
Another necessary care task involves managing suckers, which are vigorous shoots that can sprout from the rootstock below the graft union. These shoots must be promptly removed because they are genetically different from the desired fruit-producing scion. If allowed to grow, suckers will divert energy away from the upper, fruit-bearing part of the tree and may produce inferior or even non-peach fruit, depending on the rootstock used. Removing suckers by tearing them off close to the trunk directs the tree’s energy toward the high-quality peach variety above the union.