A suckering plant produces vigorous shoots, known as “suckers,” from its root system or the base of its trunk. These shoots emerge from adventitious buds on the roots or lower stem, often appearing a distance away from the main plant. Suckering is common in grafted plants, such as fruit trees, roses, and lilacs. Grafting joins a desirable upper portion (scion) onto a hardier rootstock, and suckers frequently originate from this rootstock. These growths compete with the cultivated variety and require routine management to maintain the plant’s health and appearance.
How to Identify Suckers and Watersprouts
Distinguishing between a true sucker and a watersprout is important for effective plant care, as they originate from different parts of the plant structure. A sucker is defined by its point of origin, which is always from the root system or from the stem below the graft union, meaning it arises from the rootstock. These shoots often emerge from the soil near the base of the plant or even several feet away from the trunk. Watersprouts, conversely, are fast-growing, vertical shoots that arise from dormant buds on the trunk or branches above the graft union.
Visual inspection is frequently the most reliable method for identification, particularly on grafted plants. Since the rootstock is genetically different from the scion, the sucker’s foliage often looks noticeably distinct from the rest of the tree. Sucker leaves may be a different color, size, or texture, or they might even have thorns when the main plant does not. Watersprouts, because they grow from the scion, will have foliage identical to the rest of the tree, although they typically exhibit unusually vigorous, upright growth.
To confirm a sucker’s identity, you must trace the shoot back to its source, which often requires carefully scraping away a small amount of soil at the plant’s base. If the shoot is growing from the root or from below the noticeable graft line, it is a sucker and represents the genetics of the rootstock. Identifying the exact point of emergence is also an important step before attempting removal, as improper cutting can trigger the growth of even more shoots.
The Impact of Uncontrolled Sucker Growth
Allowing suckers to grow unchecked negatively affects the overall health and productivity of the parent plant primarily through resource competition. Suckers are aggressively fast-growing shoots that draw significant amounts of water and nutrients away from the desired growth of the main canopy. This diversion of resources can reduce the vigor of the scion, leading to diminished flowering, lower fruit yields, and a weakened structure. The plant’s energy is essentially being wasted on growth that does not contribute to the desired aesthetic or harvest.
For grafted plants, the most significant risk is the eventual dominance of the rootstock over the cultivated variety. The rootstock is often selected for its hardiness or disease resistance, making its suckers naturally more vigorous than the grafted portion. If these suckers are left to mature, they can quickly outgrow the scion, effectively taking over the tree. This process, known as reversion, results in the loss of the desirable fruit or flower characteristics, causing the plant to revert to the less-desirable traits of the wild-type rootstock.
Beyond resource depletion and genetic takeover, uncontrolled sucker growth creates architectural problems for the plant. The dense, vertical clusters of shoots at the base of the trunk or along the branches can ruin the plant’s intended shape and form. This thick, crowded growth can also impede air circulation through the lower canopy, creating an environment conducive to the development of fungal diseases and providing shelter for pests.
Practical Strategies for Sucker Management
The most effective method for managing suckers is to remove them completely and as early as possible, targeting the exact point of origin to prevent regrowth. When a sucker is still young, tender, and soft, it should be rubbed off with a gloved hand or torn away from the root or stem. This tearing action is preferable to cutting because it removes the dormant growth buds at the base of the shoot, which reduces the likelihood of multiple new shoots emerging from the wound site. Simply clipping a sucker with pruning shears often leaves a small stub containing these latent buds, which quickly causes the problem to multiply.
When dealing with older, woody suckers, specialized tools and a more deliberate technique are required to ensure complete removal. You must trace the sucker back to its source, which often means carefully digging away a small amount of soil to expose the root or the base of the trunk. Once the point of origin is visible, use sharp, clean bypass pruners to cut the sucker off flush with the main root or stem, taking care not to leave a stub or damage the surrounding bark. Failing to remove the entire shoot stimulates the plant’s natural defense mechanism, leading to a flush of even more vigorous growth.
Timing is also an important consideration in the successful management of suckers, as removal during the wrong season can lead to rapid regeneration. Prevention is the better long-term strategy and involves reducing stress on the parent plant. This includes ensuring correct planting depth, as burying the graft union can encourage rootstock sprouting, and avoiding overly aggressive pruning of the canopy, which can trigger a compensatory response in the roots.
Proper cultural care, such as consistent watering and appropriate fertilization, helps keep the plant healthy and less inclined to produce stress-induced growth. While chemical controls exist, they are not typically recommended for home gardeners because the herbicides or growth regulators intended to kill the sucker can inadvertently travel to the parent plant and cause damage. Therefore, consistent, physical removal at the source remains the most reliable and safest approach for maintaining the health and appearance of suckering plants.