Tree shoots, commonly known as suckers, are undesirable growths that emerge from the base of a tree’s trunk or directly from its roots, often appearing in the surrounding lawn or garden bed. These vigorous, upright stems are distinct from the main tree structure and can be a persistent nuisance for homeowners. When left unchecked, suckers detract from the tree’s appearance and divert energy away from the main canopy. Understanding how to correctly identify and address these unwanted shoots is the first step toward maintaining a healthy and aesthetically pleasing landscape. This guide covers physical removal techniques, chemical applications, and long-term preventative care.
Why Trees Produce Suckers and Shoots
The emergence of suckers is a tree’s natural physiological response, often triggered by an imbalance in its internal systems. These shoots grow from dormant or latent buds suppressed beneath the bark of the trunk or along the root system. When the main tree is under stress or experiences a major injury, growth hormone production shifts, stimulating these dormant buds into rapid growth.
Common stressors include drought, soil compaction, disease, or mechanical damage from lawnmowers or string trimmers. Improper or excessive pruning, such as topping a tree, also disrupts the hormonal balance. This leads to a flush of new, vertical growth as the tree attempts to restore its canopy. Suckering is a survival mechanism, allowing the tree to produce more foliage for photosynthesis to generate energy needed for recovery.
In many cultivated trees, particularly fruit and ornamental varieties, suckers indicate rootstock dominance. These trees are often grafted, meaning the desirable top portion (scion) is attached to a hardy root system (rootstock). If the graft union is compromised or the scion is weakened, the vigorous rootstock sends up shoots that display the characteristics of the original, often inferior, root variety. If these rootstock shoots are not removed, they can eventually outcompete the grafted portion, effectively taking over the entire tree. Simply cutting the shoots without addressing the root problem will lead to rapid and repeated regrowth.
Proper Mechanical Removal Methods
Mechanical removal is the most direct method for eliminating suckers, but it must be executed correctly to slow regrowth. Simply clipping the shoots at ground level is counterproductive because the remaining stub stimulates latent buds to sprout multiple new shoots, worsening the problem. The goal is to remove the growth as close to its point of origin as possible, eliminating the basal buds.
For shoots emerging from the base of the trunk or the root collar, gently scrape away the surrounding soil or mulch to expose the exact point where the sucker meets the parent tree. Use sharp, clean bypass hand pruners to make a flush cut immediately next to the root or trunk. Removing the shoot flush with the source prevents leaving a protruding stub that acts as a platform for multiple new sprouts.
When suckers are young and soft, often less than pencil-sized, they can sometimes be removed by rubbing or tearing them off by hand. Tearing the sucker away from the parent root is thought to remove more dormant basal buds, which can reduce the likelihood of immediate regrowth. For larger, woodier suckers, loppers may be necessary, but the principle remains the same: cut back to the main structure without leaving a protruding stub. Avoid damaging the bark of the main trunk during this process, as new wounds can trigger further suckering.
Chemical Treatment Options
Chemical solutions are reserved for widespread suckering issues, particularly in fruit orchards, and require careful, targeted application. The most common chemical agents used are plant growth regulators (PGRs) and certain herbicides. PGRs often contain the synthetic auxin Naphthalene Acetic Acid (NAA), which is formulated to suppress bud break and slow the growth of new shoots.
NAA products are applied directly to the base of young, green suckers or to the freshly cut surface of the removed sucker. This localized application prevents the chemical from translocating into the main tree’s vascular system, which could cause canopy damage. Herbicides, such as those containing glyphosate or glufosinate, can also be used, but they carry a greater risk of unintentionally harming the parent tree.
When using a herbicide, a “cut-stump” treatment is the safer application method. This involves cutting the shoot and immediately painting or drizzling a concentrated solution onto the freshly exposed cut surface, especially the cambium layer beneath the bark. Systemic herbicides like glyphosate can travel through connected root systems, posing a significant risk in trees that exhibit root grafting, such as avocados or certain forest species. Always follow the product label directions precisely, use low-pressure sprayers to minimize drift, and remember that NAA only provides temporary suppression, typically lasting three to five weeks.
Reducing Regrowth Through Cultural Practices
Long-term suppression of suckers depends on addressing the underlying stress factors that caused the growth. A healthy tree with a balanced hormonal system is less prone to developing unwanted shoots.
Proper watering mitigates drought stress, a major trigger for suckering. During dry periods, deep, infrequent watering encourages deeper roots, making the tree more resilient. Proper mulching is also beneficial; an organic layer of wood chips three to four inches deep helps retain soil moisture and regulate temperature, reducing root stress.
Crucially, the mulch must be kept several inches away from the tree’s trunk to prevent bark decay, avoiding “volcano mulching.” Avoiding physical injury to the trunk and roots is another step. Damage from lawn equipment, such as mowers or string trimmers, creates wounds that stimulate suckers. Finally, employing correct pruning techniques, such as making cuts just outside the branch collar and avoiding excessive canopy removal, helps maintain the tree’s natural hormonal balance and prevents the emergence of new shoots.