Tree suckers are a type of adventitious growth emerging directly from the base of a tree trunk or from the root system. This growth is often undesirable because it can detract from the tree’s intended shape and divert resources away from the main canopy. Suckers represent a common maintenance challenge for anyone managing fruit trees, ornamental plants, or landscape shrubs. Understanding the nature of these shoots and their biological triggers is the first step in effective landscape management.
Distinguishing Suckers from Watersprouts
While often confused, tree suckers and watersprouts originate from different parts of the tree. Suckers specifically arise from the root system, sometimes appearing several feet away from the main trunk, or emerge from below the graft union on grafted trees. These shoots are usually genetically identical to the rootstock, which may be a less desirable variety than the upper canopy. Watersprouts, by contrast, emerge from dormant or latent buds located on the trunk or older scaffold branches higher up in the canopy. Identifying the origin point—root system versus main branch—is necessary for choosing the appropriate removal strategy, as both types of growth are generally undesirable due to their rapid, non-structural nature.
Common Causes of Sucker Formation
Sucker growth is often a biological response to environmental stress or physical damage that disrupts the tree’s internal growth regulation. When the main canopy or trunk suffers injury—such as from severe pruning, frost damage, or root cutting—the resulting hormonal disruption signals the root system to activate dormant buds and produce new shoots as a survival mechanism. This process is common in grafted trees, where a desirable variety (scion) is joined to a vigorous root system (rootstock). If the scion is damaged or stressed, the rootstock may rapidly produce suckers that have different characteristics, such as different foliage or fruit, than the intended upper tree. Certain tree species, including lilacs, cherries, plums, and some poplar varieties, also possess a natural genetic tendency to sucker aggressively, making consistent removal a necessity.
How Suckers Affect Tree Health
The primary detrimental effect of suckers is the siphoning of energy, water, and nutrients away from the main canopy and fruit production. Because these shoots are programmed for rapid growth, they compete directly with the desirable parts of the tree for resources, which reduces the vigor of the main tree and limits the size or quality of fruit yields. Dense sucker growth at the base of the tree compromises aesthetics and structural integrity by obscuring the trunk and ruining the tree’s intended form. This growth also impedes air circulation near the base, creating a humid, shaded microclimate favorable for the development of fungal diseases or insect infestations.
Methods for Managing and Removing Suckers
Effective removal requires proper technique to avoid stimulating further regrowth from the remaining stub. The best method is to remove young, succulent shoots by tearing them downward and away from the trunk or root flare; this action removes the dormant buds at the base of the sucker, which is more effective than a simple cut. If the sucker has matured, use sharp pruning shears to cut the shoot as close as possible to its point of origin, ensuring no stub remains. Leaving a short stub encourages the development of multiple new shoots, so consistent, early removal is necessary to starve the root buds of energy. Prevention focuses on minimizing the stress that triggers growth, such as avoiding root disturbance from tilling or mowing too close to the trunk. While chemical inhibitors are available, mechanical removal is the preferred method for long-term management, as incorrect application can damage the healthy tissue of the parent tree.