Tree suckers are shoots that sprout from a tree’s roots or from the base of its trunk, drawing energy from the parent tree without contributing much in return. They look like small, fast-growing stems poking up from the ground near the tree or clustered around the trunk at soil level. Left alone, suckers divert water and nutrients away from the canopy, can crowd out the tree’s intended form, and in grafted fruit trees can eventually overtake the desirable variety altogether. Removing them is straightforward in most cases, but the method matters more than people expect.
What Exactly Is a Tree Sucker
A sucker is a vegetative shoot that grows from a tree’s root system or from dormant buds at the very base of the trunk, a zone sometimes called the root collar. Because suckers originate below or at ground level, they are genetically identical to whatever tissue they sprout from. On an ungrafted tree, that means the sucker is a clone of the parent. On a grafted tree, though, the sucker comes from the rootstock, not the grafted variety on top, and the two can be completely different species. That distinction is critical for fruit trees, ornamental grafts, and anything budded onto a different root system.
Suckers differ from water sprouts, which are the vigorous vertical shoots that erupt from branches higher up in the canopy. Water sprouts grow from latent buds on branches or the trunk well above ground. Both are unwanted in most situations, and both grow aggressively, but they arise from different places and for somewhat different reasons. If the shoot is coming from the ground or from below the graft union on a fruit tree, it is a sucker. If it is shooting straight up from an existing branch, it is a water sprout.
Why Trees Send Up Suckers
The underlying trigger is hormonal. In a healthy, intact tree, a plant hormone called auxin flows downward from the canopy through the trunk and into the roots. That steady supply of auxin suppresses the dormant buds along the root system, keeping them from activating. Research on aspen has shown that when auxin was applied directly to cut stumps, root suckering and basal sprouting were inhibited, while blocking auxin’s downward transport through the wood significantly increased suckering.
Anything that disrupts the flow of auxin from canopy to roots can unleash suckers. The most common triggers include:
- Heavy pruning: Removing a large portion of the canopy suddenly reduces the total auxin supply reaching the roots, and dormant root buds respond by sprouting.
- Root damage: Construction, trenching, soil compaction, or even aggressive lawn mowing over shallow roots can injure root tissue and trigger a suckering response. A study on black poplar found that root suckers appeared in control plants specifically after their root systems had been damaged.
- Trunk injury or disease: A tree under stress from storm damage, canker, or decay may lose its ability to transport auxin normally, prompting the root system to send up replacement shoots as a survival strategy.
- Tree removal: When a tree is cut down, the living root system loses its entire auxin source. The roots, still full of stored energy, push up suckers aggressively. This is why stumps of certain species can produce a thicket of new shoots for years.
Stress suckering is the tree’s way of hedging its bets. If the canopy is compromised, the root system tries to establish new above-ground growth to keep photosynthesis going. From the tree’s perspective, suckers are emergency backup plans.
Which Trees Sucker the Most
Some species are notorious for suckering, while others rarely produce a single root shoot. Aspens and poplars are among the most aggressive suckering trees in temperate climates. Entire aspen groves can be a single genetic individual connected by a shared root network, with each “tree” being a sucker that grew to full size. Research on black poplar confirmed that most clones in a clonal archive formed root suckers, and the number of suckers correlated positively with the above-ground size of the plants.
Other common suckering species include lilac, crabapple, plum, cherry, elm, black locust, sumac, tree of heaven, and silver maple. Fruit trees grafted onto vigorous rootstocks are especially prone. Micropropagated rootstocks, a modern propagation technique used widely in commercial orchards, have been observed to sucker even more heavily than traditionally propagated ones.
On the less troublesome end, most conifers rarely sucker from roots. Oaks, maples other than silver maple, and many tropical hardwoods are generally modest suckerers under normal conditions. But even a normally well-behaved tree can throw suckers if stressed badly enough by root damage, drought, or severe pruning.
Identifying Suckers on Grafted Fruit Trees
On a grafted apple, pear, cherry, or citrus tree, suckers represent a specific headache. The graft union, a visible bulge or scar usually a few inches above soil level, is where the desirable fruiting variety meets the rootstock. Any shoot emerging below that line is rootstock growth and will not produce the fruit you planted the tree for. If allowed to grow, rootstock suckers compete directly with the grafted canopy and can even dominate it over time, effectively turning your Honeycrisp apple back into whatever anonymous crabapple stock it was grafted onto.
Rootstock suckers often look slightly different from the grafted variety. Leaf shape, color, and texture may differ. On apple trees, rootstock suckers frequently have smaller, more pointed leaves than the named variety above the graft. On citrus, rootstock suckers tend to have thornier stems and trifoliate leaves compared to the smooth, thornless growth of the grafted top. These visual cues are your first hint. If a shoot is growing from below the graft union and its foliage looks different from the rest of the tree, remove it.
Distinguishing between a sucker and a seedling growing near the base can sometimes be tricky. Research on aspen found that field methods for telling seedlings from suckers achieved about 99 percent accuracy with young growth, but accuracy dropped to around 90 percent after one summer of growth as the two became more similar in appearance.
How to Remove Suckers Properly
The removal method affects whether the sucker comes back. Simply cutting a sucker at ground level with pruners or a mower often makes the problem worse, because the cut stimulates the dormant buds at the base of the sucker to push out even more shoots. You can turn one sucker into three or four this way.
The most effective physical removal technique is to tear or pull the sucker away from the root rather than cutting it cleanly. This removes the bud cluster at the sucker’s origin point, reducing the chance of regrowth. For trunk-base suckers, scrape away a little soil to expose where the sucker connects to the root or trunk, then pull it off with a firm downward-and-outward motion. The goal is to rip the sucker away at its base, taking the basal buds with it. It is messier than a clean pruning cut, and that is the point.
For suckers emerging from roots away from the trunk, you may need to dig down to the root and either pull or cut the sucker flush with the root surface. Some gardeners use a sharp spade to sever the sucker just below the soil line. Timing matters: suckers are easiest to pull when they are young, green, and flexible. Once they woody up and develop their own root system, removal becomes harder and regrowth more likely.
Trunk-Base Suckers
Suckers growing right at the base of the trunk, especially on grafted trees, should be removed as soon as they appear. Expose the base, pull or cut them as close to the trunk tissue as possible, and avoid leaving a stub. On fruit trees, check the base two or three times during the growing season, since rootstock suckers can appear repeatedly throughout spring and summer. Consistent removal eventually weakens the dormant buds in that area, and the suckering slows over successive years.
Root Suckers in the Lawn or Garden
Suckers popping up in the lawn or garden bed several feet from the parent tree are connected underground by a lateral root. Mowing them down repeatedly will weaken them over time, but it is a slow process and they keep coming back for a while. A better approach is to dig down to the connecting root and sever it, then pull the sucker. If the root is shallow, this takes only a few minutes per sucker. If you are dealing with a prolific suckering species like tree of heaven or black locust and the suckers cover a wide area, you may need to combine digging with targeted herbicide treatment.
Chemical Options for Sucker Control
When physical removal is not keeping up with the problem, targeted herbicide application can help. The most commonly used product is a glyphosate-based herbicide, applied carefully to the sucker foliage or cut surface. Research on apple orchards found that spraying suckers with glyphosate to the point of runoff in midsummer caused no damage to the parent trees, either in the year of treatment or the following year, and no detectable glyphosate residues appeared in the leaves of the parent apple trees.
The key word in that research is “careful.” Glyphosate is non-selective, meaning it kills whatever green tissue it contacts. Spraying it on suckers that are physically connected to a living tree you want to keep requires precision. Use a small brush or sponge applicator rather than a pump sprayer to avoid drift onto the trunk or canopy. Some orchardists use a wipe-on application, literally painting the herbicide onto the sucker’s leaves or freshly cut surface with a cloth or foam brush.
Growth regulators containing naphthaleneacetic acid (NAA), a synthetic auxin, are sometimes used commercially to suppress sucker regrowth on fruit trees. The logic tracks with the biology: since natural auxin from the canopy suppresses suckering, applying synthetic auxin directly to the sucker origin can mimic that signal. NAA-based products are available from horticultural suppliers, though they are more common in commercial orchards than in backyard settings. Effectiveness varies with species, concentration, and timing of application.
What Not to Do
A few common approaches either do not work or make things worse:
- Mowing repeatedly as your only strategy: This keeps suckers short but stimulates the root system to produce more of them. You end up in an arms race you cannot win without also addressing the root connection.
- Pouring salt, bleach, or diesel on suckers: These home remedies can damage soil, kill nearby plants, contaminate groundwater, and harm the parent tree’s root system. They are not effective sucker control and create bigger problems than they solve.
- Ignoring suckers on grafted trees: Rootstock suckers left to grow on a grafted fruit tree can outcompete the desirable variety within a few seasons. The rootstock is typically chosen for vigor, which means its suckers grow faster than the grafted top. Procrastination costs you the tree you paid for.
- Applying broadleaf herbicide near the parent tree’s root zone: Systemic herbicides absorbed by sucker foliage can travel through the shared root connection back to the parent tree. Be cautious about which product you use and how close the sucker is to the trunk.
Preventing Suckers in the First Place
Complete prevention is not realistic for naturally suckering species, but you can reduce the frequency and severity of the problem. The single most effective preventive step is to avoid stressing the tree’s root system. That means:
- Minimize root disturbance: Keep construction, trenching, and digging away from the root zone, which extends well beyond the canopy drip line for most trees.
- Prune moderately: Avoid removing more than about a quarter of the living canopy in a single season. Severe topping or over-pruning triggers both suckers and water sprouts as the tree tries to replace lost leaf area.
- Maintain tree health: Adequate watering during drought, proper mulching, and treating diseases promptly all reduce the stress signals that trigger suckering.
- Choose rootstocks wisely: When planting grafted fruit trees, ask about the rootstock’s suckering tendency. Some rootstocks are known for heavy suckering; others are bred to produce fewer root shoots.
For trees already in the ground, a thick layer of mulch over the root zone can suppress weak suckers by blocking light. Mulch alone will not stop a determined sucker from a vigorous root system, but it reduces the number of small ones that make it to the surface and keeps you from accidentally damaging roots with a mower.
When Suckers Are Actually Useful
Not every sucker is a nuisance. For some species, root suckering is a primary means of natural reproduction and ecological resilience. Aspen forests regenerate almost entirely through root suckers after fire or logging. The existing root network, packed with stored carbohydrates, sends up dense clusters of new shoots that grow rapidly. Without this suckering ability, aspen would recover far more slowly from disturbance.
Gardeners and restoration ecologists sometimes exploit suckering intentionally. A sucker can be severed from the parent root, dug up with some root attached, and transplanted as a new plant. This is essentially free clonal propagation. Lilac, plum, raspberry, and various ornamental shrubs are commonly propagated this way. The new plant is genetically identical to the parent, which is useful when you want to reproduce a specific variety without grafting.
That said, not all species cooperate equally with this approach. Some dry forest species that resprout vigorously from roots after disturbance do not root successfully when their root cuttings are taken and planted under controlled conditions, even with auxin treatment applied.
Dealing with Suckers from Removed Trees
One of the most frustrating suckering scenarios happens after a tree has been cut down. The stump and root system remain alive, sometimes for years, and the stored energy in the roots drives wave after wave of suckers. Species like tree of heaven, black locust, aspen, and ailanthus are legendary for this. You can cut down a 40-foot tree and spend the next five years fighting its offspring.
The most effective approach for a removed tree is to treat the freshly cut stump immediately with a concentrated glyphosate or triclopyr herbicide, painted or sprayed onto the cut surface within minutes of felling. The living tissue absorbs the herbicide and translocates it into the root system, killing the roots before they can send up suckers. If the stump is not treated at the time of cutting, the window for effective chemical treatment narrows over the following days as the cut surface dries and seals.
If you missed the window and suckers are already appearing, the two-pronged strategy is to let the suckers grow enough foliage to be metabolically active (usually 12 to 18 inches tall), then treat them with a foliar herbicide application. The suckers’ leaves absorb the product and transport it back through the root system. Multiple treatments over one or two growing seasons are usually needed to exhaust the root reserves. Stump grinding alone, without herbicide, often fails because it leaves living root fragments throughout the soil that continue to produce suckers.
For people who prefer to avoid herbicides entirely, persistent physical removal is the alternative. Cut or pull every sucker as soon as it appears, repeatedly, over multiple growing seasons. Each time the roots spend energy producing a sucker that gets removed before it can photosynthesize and feed the root system, the roots lose a little more of their stored reserves. Eventually the roots starve, but “eventually” can mean two to five years for aggressive species. Consistency is everything with this approach: letting even a few suckers grow unchecked for a month recharges the root system and resets your progress.