Most modern orchard and backyard apple trees appear smooth and thornless. However, the common commercial varieties, such as ‘Gala’ or ‘Fuji,’ generally do not possess these sharp defenses, but their wild ancestors and certain root systems do. Many ancestral species of the domesticated apple (Malus domestica) naturally develop these protective structures. The absence of thorns on the trees you typically see is a direct result of centuries of selective cultivation and breeding practices.
The Biological Nature of Apple Tree Thorns
The sharp, woody points found on wild apple trees are classified as true thorns. Botanically, a true thorn is a modified branch or shoot. This means the thorn contains vascular tissue, connecting it directly to the tree’s internal water and nutrient transport system. A thorn develops when a bud that would normally produce a leafy branch hardens into a sharp, durable point.
These structures serve as a natural defense mechanism for wild apple species, protecting young trees from browsing herbivores like deer. This differs from prickles, such as those on roses, which are merely sharp outgrowths of the outer skin layer. Because the apple tree’s thorn is an integral part of the stem structure, it is a robust deterrent.
Why Modern Cultivation Removed the Thorns
The shift from thorny wild apples to smooth-stemmed cultivated varieties was driven by horticulture and commercial efficiency. Handling thorny branches complicates orchard management, including annual pruning and harvesting the fruit. Laborers picking apples would experience injuries, slowing down the process and increasing costs.
To solve this practical problem, growers systematically favored and propagated trees with a reduced tendency to form thorns. This selective breeding, combined with grafting, led to the dominance of thornless varieties in commercial orchards. Grafting involves joining a desirable thornless variety (the scion) to a separate root system, ensuring the fruit-producing portion remains smooth.
Developing thornless scion wood has made pruning safer and faster. It also allows for the implementation of high-density orchard systems. Modern systems pack trees closely together and train them to narrow, manageable forms, which would be impractical if the branches were covered in sharp points.
Distinguishing Thorny Look-Alikes
If you encounter a thorny tree that appears to be an apple tree, it is likely one of two common scenarios. The first source of confusion is often the crabapple (Malus species). Crabapples are closely related to domesticated apples but frequently retain their natural, defensive thorns. They are widely used as ornamental trees.
The second common reason for a thorny apple tree is the presence of suckers growing from the rootstock. Almost all commercial apple trees are grafted, meaning the thornless top part is joined to a different root system. If the rootstock naturally produces thorns, any shoots or suckers that sprout below the graft union will display these thorny characteristics. These suckers must be pruned off to prevent them from sapping energy from the main tree.