Plant suckers are vigorous vegetative shoots that sprout from a plant’s roots, base, or lower trunk rather than from its main branches. They grow rapidly, drawing water and nutrients away from the parts of the plant you actually want to thrive, whether that’s fruit, flowers, or a well-shaped canopy. Gardeners encounter them on everything from tomato vines to grafted fruit trees to rose bushes, and the reason they appear, along with the best way to deal with them, varies quite a bit depending on the plant.
What Counts as a Sucker
The term “sucker” gets used loosely in gardening, which causes some confusion. In the strictest botanical sense, a sucker is a shoot that originates from the root system or the underground portion of a stem. These are true root suckers, and they can pop up some distance from the parent plant because they emerge along lateral roots spreading through the soil. Aspens are a classic example: a single aspen can send up dozens of root suckers, forming what looks like a grove of separate trees but is actually one connected organism. Research on aspen has shown that these vegetative recruits stay physiologically connected to the parent, sharing water and nutrients through the root network for decades.
In everyday garden talk, though, “sucker” also refers to shoots that sprout from the base of a trunk (called basal shoots), from below a graft union on fruit trees and roses, or from the leaf axils on tomato plants. These aren’t all the same thing biologically, but the gardener’s concern is the same in each case: an unwanted shoot is diverting energy from the plant’s productive growth. Understanding which type you’re dealing with matters, because the removal technique and urgency differ.
Why Suckers Form
Sucker growth is controlled primarily by plant hormones, especially auxin. In an intact, healthy plant, auxin produced in the shoot tips and young leaves travels downward through the stem, suppressing dormant buds along the roots and lower trunk. When something disrupts that flow of auxin, those buds wake up and push out new shoots. Research on trembling aspen found that the greatest number of root suckers emerged after complete removal of the shoot, averaging roughly 68 per plant. Defoliated and debudded stems were the main source of inhibitory signals, and when researchers applied synthetic auxin directly to cut stumps, it suppressed suckering and basal sprouting.1Oxford Academic (Tree Physiology). Signals controlling root suckering and adventitious shoot formation in aspen (Populus tremuloides)
This explains why you often see a flush of suckers after heavy pruning, storm damage, or the death of a major limb. The plant’s normal hormonal “keep dormant” signal has been disrupted, and latent buds take their chance. Stress from drought, root damage during construction, disease, or insect attack can trigger the same response. The plant is essentially hedging its bets: if the main canopy is in trouble, sending up new shoots from the base or roots is a survival strategy.
External factors play a role too. In bananas, sucker production is influenced by planting depth, spacing, and even the season of planting, alongside internal genetic factors like ploidy level and genomic makeup.2Journal of Tropical Agriculture. Sucker production in banana Crowded or shallowly planted specimens tend to produce more suckers, giving gardeners at least some control through how they manage planting conditions.
How Suckers Steal Resources
The core problem with suckers is simple: they compete with the parts of the plant you care about. A sucker is a new growing point that needs water, minerals, and sugars. Every calorie of energy the plant routes to a sucker is a calorie that doesn’t go to fruit, flowers, or healthy canopy growth. In banana cultivation, this trade-off is well documented. After flowering, the developing bunch and any suckers become competing sinks for the plant’s photosynthetic output. Removing all suckers during bunch development can increase fruit size and overall bunch weight, while also reducing light competition that changes the plant’s shape and size.3Elsevier / Field Crops Research. Parent plant vs sucker − how can competition for photoassimilate allocation and light acquisition be managed in new banana hybrids?
On ornamental plants like lilacs, crepe myrtles, or roses, suckers create a bushy, cluttered look at the base that detracts from the plant’s form. They also crowd airflow around the base, which encourages fungal disease. And on any plant, suckers that are allowed to grow unchecked eventually become thick, woody stems that are harder to remove cleanly and leave bigger wounds when you finally cut them.
The Special Problem with Grafted Plants
Suckers are a particular headache on grafted plants, and this is where misidentifying them can cause real trouble. Many fruit trees, roses, and ornamental trees are sold as grafted specimens, meaning the top portion (the scion, chosen for its fruit or flowers) is joined to a rootstock chosen for vigor, disease resistance, or size control. The graft union is usually visible as a slight bulge or scar near the base of the trunk.
Any shoot that emerges below the graft union comes from the rootstock, not the desirable scion variety. If you let rootstock suckers grow, they will have different characteristics from the top of the plant, often producing inferior fruit, different leaves, or thorny wild-type growth in the case of roses. Worse, because rootstocks are selected for vigor, their suckers tend to be aggressive growers. Left unchecked, rootstock suckers can outcompete the grafted top entirely, effectively taking over the plant. Research on greenhouse rose propagation confirmed that removing or preventing buds on the rootstock is essential to minimize wild suckering.4Elsevier. Cutting-grafts as a means to propagate greenhouse roses
For grafted fruit trees, the telltale signs of a rootstock sucker include leaves that look different from the rest of the tree and shoots emerging from below the soil line or below the visible graft union. On roses, rootstock suckers often have seven leaflets per leaf instead of the five typical of most garden rose varieties, and the thorns may look different. These suckers should always be removed promptly and completely.
Tomato Suckers and Pruning for Better Harvests
Tomato “suckers” are a slightly different beast from the root suckers on trees, but the name has stuck. These are side shoots that sprout in the angle (the axil) between a leaf branch and the main stem. On indeterminate tomato varieties, which keep growing taller all season, every leaf axil can produce a sucker that grows into a full secondary stem with its own flowers and fruit. The result is a sprawling, dense plant that produces many small fruit.
Pruning these suckers is one of the most debated topics in vegetable gardening, but the research is fairly clear on what happens when you do it. Trials comparing pruned and unpruned indeterminate tomato lines found that plants pruned to two stems produced the highest number of marketable fruits per plant, while unpruned plants produced the most unmarketable fruit.5ISHS Acta Horticulturae. Assessment of the Effect of Pruning Systems on Plant Developmental Cycle – Yield and Quality of Selected Indeterminate Tomato Lines A study in Ghana’s Guinea Savanna zone found even more dramatic results: two-stem pruning combined with wire trellising increased marketable fruit weight by about 69% and total fruit yield by roughly 76% compared to unpruned, unstaked controls.6Advances in Agriculture. The Role of Staking and Pruning Methods on Yield and Profitability of Tomato (Solanum lycopersicum L.) Production in the Guinea Savanna Zone of Ghana
The practical takeaway for home gardeners: if you grow indeterminate tomatoes, letting one or two suckers develop into secondary stems and removing the rest gives you the best balance of fruit quantity and quality. Pinch or snap off unwanted suckers when they’re small, ideally under a few inches long, which the plant heals from quickly. Determinate tomatoes, the bush-type varieties that set all their fruit at once and then stop growing, generally shouldn’t be suckered aggressively because you’ll reduce total yield with little benefit to fruit size.
How to Remove Suckers on Trees and Shrubs
The method for removing suckers depends on where they’re coming from and how large they’ve gotten. Here are the common scenarios:
- Root suckers: These emerge from lateral roots, sometimes several feet from the trunk. The best approach is to dig down to where the sucker connects to the root and tear or cut it off flush with the root surface. Simply cutting a root sucker at ground level tends to stimulate more suckers from the same spot, because you’ve left the dormant buds intact. Pulling or tearing removes more of the bud tissue at the base.
- Basal suckers: Shoots sprouting from the base of the trunk should be cut as close to the trunk as possible. On grafted plants, trace the sucker down to its point of origin below the graft union and remove it there. Don’t just clip it at soil level.
- Tomato suckers: Pinch these off with your fingers when they’re small. For larger suckers, use clean pruners to make a neat cut. Avoid tearing, which can open the stem to disease.
- Water sprouts: These are the vigorous, straight vertical shoots that erupt from the upper branches of trees, often after heavy pruning. Though not technically root suckers, they’re managed the same way: cut them off at their base where they meet the branch. Leaving a stub invites regrowth.
Timing matters. The best time to remove suckers on most trees and shrubs is during the growing season when you can spot them easily and the plant is actively healing wounds. Removing suckers during dormancy is less ideal because you can’t always distinguish them from desirable growth, and some species respond to dormant-season cuts with an even bigger flush of new suckers in spring.
For persistent suckering species like certain plum rootstocks, poplar, or sumac, you may need to repeat sucker removal several times a season. Some commercial growers use growth regulators (synthetic auxins applied to cut surfaces) to suppress regrowth, echoing the mechanism researchers demonstrated in aspen.1Oxford Academic (Tree Physiology). Signals controlling root suckering and adventitious shoot formation in aspen (Populus tremuloides) Home gardeners rarely need to go that far, but consistent removal before suckers become woody is the single most effective habit.
Pruning Shrubs to Prevent Suckering Problems
For shrubby plants like blueberries, the line between “sucker” and “desirable new cane” gets blurry. Blueberry bushes naturally produce new canes from the base, and you actually want some of them to replace aging, less productive wood. The goal isn’t to eliminate all basal growth but to manage it so the plant stays productive and open. Pruning in blueberries serves multiple purposes: promoting postharvest growth of new foliage and fruiting wood, balancing the ratio between vegetative and reproductive growth, reducing disease and certain insect pressure, and encouraging new cane growth that extends the plant’s productive life.7EDIS. Pruning Southern Highbush Blueberry in Florida
The same principle applies to many other fruiting shrubs. You’re not fighting sucker growth so much as curating it: keeping the strongest, best-positioned new canes and removing the weak, crowded, or poorly placed ones. This is a different mindset from the “remove all suckers” approach used on grafted trees, and confusing the two can lead to over-pruning shrubs that actually benefit from renewal growth.
When Suckers Are Worth Keeping
Not every sucker is an enemy. In some situations, sucker growth is exactly what you want. Propagation is the most obvious case. Many plants can be propagated by digging up a root sucker with a section of root attached and transplanting it. Raspberries, blackberries, and many ornamental shrubs spread naturally this way, and gardeners can take advantage of it to start new plants for free.
In banana production, suckers are the primary means of propagation. Growers select the healthiest “sword sucker” (one with narrow, upright leaves indicating strong growth) and allow it to develop while removing weaker ones. The chosen sucker becomes the next fruiting plant in a continuous cycle. Managing which suckers to keep and which to remove is central to banana farming rather than a side chore.2Journal of Tropical Agriculture. Sucker production in banana
Suckers also play an ecological role in forest systems. Vegetative recruits that stay connected to the parent plant benefit from shared resources through the root network, which gives them much higher survival rates during establishment than seedlings that have to fend for themselves. Research on the Chilean tree Eucryphia cordifolia found that this resource sharing allows vegetative recruits to thrive in conditions where seedlings from seeds would struggle, effectively widening the range of environments where the species can regenerate.8Oxford Academic. Physiological differences between root suckers and saplings enlarge the regeneration niche in Eucryphia cordifolia Cav In aspen forests, suckering is the dominant form of reproduction, and a clonal aspen grove can persist for thousands of years through successive waves of root suckers replacing aging trunks.
How Long Suckers Stay Dependent on the Parent
If you plan to dig up a sucker and transplant it, timing matters more than most gardening guides let on. A common assumption is that once a sucker has its own leaves and looks like an independent plant, it can survive on its own. But research on aspen tells a more nuanced story. When researchers severed various portions of the root systems connecting suckers to parent trees, they found that aspen suckers remain heavily dependent on the parent root system for at least 25 years after initial suckering. The distal portion of the parent root, the part extending away from the trunk, contributed more to the sucker’s growth than the proximal portion closer to the parent tree. New roots that formed at the sucker’s own base contributed little during the first six years, then became progressively more important, accounting for roughly half of annual stem growth by age 25.9CrossRef API / Ecology. Effect of Pruning the Parent Root on Growth of Aspen Suckers
Aspen is an extreme case of prolonged dependency, and most garden plants aren’t nearly as clingy. But the underlying point is worth keeping in mind: a sucker that looks self-sufficient above ground may still be drawing heavily on the parent’s root system below ground. When transplanting suckers from trees or shrubs, taking a generous section of root with the sucker and giving it extra attention during establishment improves the odds considerably.
Common Mistakes When Dealing with Suckers
A few errors come up repeatedly among gardeners dealing with sucker problems. The first is mowing or cutting root suckers at ground level and calling it done. This removes the visible growth but leaves the buds at the base intact and often stimulates even more suckers in response. It’s the plant-care equivalent of pulling a weed off at the stem: temporarily tidy, ultimately counterproductive.
The second is aggressive pruning of a tree and then being surprised by a wave of suckers. Heavy pruning removes the auxin-producing shoot tips and leaves that normally keep dormant buds suppressed. If you need to do major corrective pruning on a tree, spread it over two or three years rather than taking everything off at once. This keeps enough canopy intact to maintain hormonal suppression of sucker buds.
The third is suckering determinate tomatoes the same way you’d sucker indeterminate ones. Determinate tomatoes have a built-in stop point for growth. Removing their side shoots doesn’t redirect energy into bigger fruit the way it does with indeterminate varieties; it just reduces the total number of fruiting branches, and you end up with a smaller harvest.
Finally, on grafted plants, some gardeners mistake rootstock suckers for normal low branches and leave them alone, or even train them as part of the tree. Over years, the rootstock growth can dominate the grafted top, and you end up with a tree producing wild-type fruit or a rose bush that’s reverted to a thorny, single-petaled understock. Checking below the graft union periodically and removing any growth there catches the problem early.
Chemical Sucker Control in Commercial Settings
Home gardeners rarely need to reach for chemicals to manage suckers, but in commercial orchards and plantations, the economics of hand-removing suckers from hundreds or thousands of trees can make chemical control attractive. Products containing naphthaleneacetic acid (NAA), a synthetic auxin, are sometimes applied to the trunk or cut sucker stubs to suppress regrowth. The logic tracks directly with the hormonal mechanism: providing auxin externally mimics the signal the intact canopy would normally produce, telling dormant buds to stay dormant. The aspen research demonstrated this principle directly, showing that applying indole-3-acetic acid to excised stumps inhibited both root suckering and basal stem sprouting.1Oxford Academic (Tree Physiology). Signals controlling root suckering and adventitious shoot formation in aspen (Populus tremuloides)
In practice, these treatments work best as a supplement to physical removal, not a replacement. They reduce the number of regrowth cycles you have to deal with but rarely eliminate suckering entirely, especially on species with an aggressive suckering habit. For the home gardener, the simpler and more reliable approach remains consistent physical removal during the growing season, catching suckers when they’re young and easy to pull or snip off cleanly.