Tree suckers are unwanted, fast-growing shoots that arise from the roots or the base of a tree. These growths are visually unappealing and divert energy and nutrients away from the main canopy, potentially compromising the tree’s health and stability. Understanding the origins of these persistent shoots is the first step toward effective management. This article provides practical methods for eliminating tree suckers and implementing preventative strategies to keep them from returning.
Identifying Tree Suckers and Their Cause
Tree suckers are distinct from water sprouts, though both are forms of adventitious growth from dormant buds. Suckers specifically emerge from the root system or the trunk below the graft union, often appearing in the soil some distance from the tree’s base. In contrast, water sprouts develop along the trunk and branches higher up in the tree’s structure. Both types of growth are typically a physiological response to stress or injury. Common causes include root damage from construction or lawnmower impact, environmental stress like drought, or excessive pruning. Grafted trees, such as many fruit varieties, produce suckers when the hardy rootstock attempts to grow its own foliage, which will not match the desired cultivar. These shoots can weaken the tree and ruin its intended structure.
Effective Mechanical Removal Techniques
Mechanical removal is the preferred method for controlling suckers because it avoids the risks associated with chemical use near the parent tree. The most effective technique involves removing the shoots when they are young and tender, ideally small enough to be rubbed or gently pulled off by hand in the spring. This action disrupts the growth point, which can be more successful than cutting alone in preventing immediate regrowth. For larger, more established suckers, use sharp pruning shears or loppers to make a clean cut as close to the source as possible. Trace the sucker back to the point where it emerges from the root or the trunk and cut it flush, without leaving a small stub. Leaving a stub prompts the dormant buds at the base to produce multiple new shoots, worsening the problem. If a sucker is emerging from a root below the soil line, carefully excavate soil to ensure the cut is made directly at the root, then cover the root back up.
Using Chemical Treatments Safely
Chemical treatments are generally reserved for persistent or widespread suckering problems, as they carry a risk of harming the main tree. The active ingredients most commonly used by homeowners are glyphosate and triclopyr, found in various brush killers. Glyphosate is a non-selective herbicide, meaning it can damage any green plant tissue it contacts. Triclopyr is selective for broadleaf plants and is often effective on woody growth. For the safest and most targeted application, paint an undiluted or highly concentrated herbicide solution directly onto the fresh cut surface of the sucker immediately after cutting it. This cut-stump method ensures the chemical is absorbed by the vascular system of the sucker before the wound seals over. Using a small foam paintbrush helps prevent dripping and accidental contact with the parent tree’s bark or surrounding desirable plants. Care must be taken to only treat the cut surface of the sucker, as the herbicide can translocate and cause injury or death to the entire plant.
Long-Term Prevention Strategies
The most effective long-term strategy for controlling tree suckers is to minimize the stress that triggers their growth. This involves maintaining the overall health of the tree through proper cultural practices. Adequate watering, especially during periods of drought, and appropriate fertilization help keep the tree vigorous and less likely to produce stress-related growth. Avoiding physical damage to the trunk and root zone is equally important, as injury stimulates the latent buds to sprout. Use a layer of mulch around the base of the tree, keeping it a few inches away from the trunk, to discourage mowing or string trimming near the root flare. Proper pruning techniques are also a preventative measure. Avoid excessive removal of live wood, limit pruning to no more than one-third of the tree’s canopy, and never “top” a tree, as these practices cause significant stress and a flush of new growth.