Sucker

sucker [ SUK-er ] noun: a shoot originating underground from the root or stem of a plant. verb: to form shoots or sprouts from the root or stem of a plant; to remove suckers from a plant

A sucker is a sprout or slim branch of new growth at the root or base of the plant. Suckers are often able to put out their own roots and become new plants that are clones, genetically identical to the parent plants. The MGNV Tried & True native plant fact sheet uses the verb form to say the shrub Itea virginica (Virginia sweetspire) “suckers to form thickets.” Suckering can be a positive quality if one wants more of a given plant, though in some plants suckering is regarded as a negative or aggressive factor. For example, suckers that form beneath a graft union will resemble the root stock, not the scion, and should be removed promptly so that they do not replace the variety of the main stem.

Native *Itea virginica* (Virginia sweetspire) suckers in November.
Photo © Elaine Mills

The suckers of fast-growing native *Alnus serrulata* (smooth alder) can form thickets and are often used in wetlands restoration.
Photo © Mary Free

*Corylus avellana* ‘Contorta’ (corkscrew hazel) suckers in October. Photo © Christa Watters

Suckering *Populus tremuloides* (quaking aspen) at the Regional Parks Botanic Garden in Berkeley, California. One stem can produce a grove of hundreds of clones. Photo courtesy Daderot

Suckering is the primary way that some aspen trees, particularly Populus tremuloides (quaking aspen) propagate; seeding out is very rare. Suckering from a single tree can create a whole grove, a phenomenon common in the American West. Cutting off the suckers stimulates more of them to grow.

Suckering can also be a sign of age, insect or weather damage, disease, or other weakening factor. Fraxinus (ash) trees in Virginia, currently susceptible to emerald ash borer (EAB) damage, often show suckering as a symptom, although it is not always an indicator of EAB, and certainly not diagnostic for it. Stressed trees may also produce upright shoots off of their trunk or branches, although these so called water sprouts naturally occur in species like dogwood, maple, and oaks.

Suckers should be removed as needed to preserve the look and form of the tree and to prevent crowding. Photo © Joyce Hylton

When removing water sprouts with a loppers or saw, care should be taken not to damage the adjacent trunk. Photo © Joyce Hylton

Gardeners who do not wish a particular tree or shrub to form more plants or create thickets, groves, or hedges, can remove the suckers, demonstrating the other use of the verb “to sucker.” For information on pruning, see North Carolina State Extension’s General Pruning Techniques.

References

Erler E. February 26,2021. Can water sprouts and suckers be prevented on trees? University of New Hampshire Extension.

Frequently Asked Questions About Emerald Ash Borer. Nebraska Forest Service. (accessed October 8, 2021).