Vigorously growing stems arising from the roots of ornamental trees are a commonly observed phenomenon in the landscape. Otherwise known as suckers, the emergence of these subsurface stems indicate that the plant is under some sort of stress. Environmental conditions, poor planting practices, excessive pruning, and very commonly, mechanical damage can induce suckering.

One of the most common culprits of suckering involves using equipment too closely to the trunk. Haphazard string trimming or mowing around the trunk/exposed roots of a tree presents wounding opportunities which may enhance pest and disease entry as well as spur sucker development. These suckers sap the plant’s resources, supporting its own growth rather than the overall tree. Indeed, the plant’s energy that could be spent supporting healthy canopy growth is now redirected to support the sucker. If left unaddressed, the overall character and form of the tree may suffer.

Removing suckers as soon as they appear is a best management practice. Oftentimes, suckers shoot up in springtime as the landscape reawakens. Pruning suckers as close to the point of emergence by making a clean cut at the trunk/sucker interface is recommended; however, if addressed early, newly emerged suckers may be ripped off the plant by hand. In some cases, light hand excavation may be necessary to reach the point of origin, especially below ground. Using simple hand tools, such as bypass or anvil pruners, is a solution for small suckers. If left unchecked, suckers may reach a size where saws and loppers may be necessary. Simply severing suckers once seldom suffices. Regrowth is to be expected, requiring repeated removal throughout the season. The importance of a clean, flush cut is not just for temporary relief, it reduces regrowth in the future. Poor pruning practices (i.e., not cutting the sucker far back enough) leaves a stub that may yield several more suckering shoots than before.

While pruning juvenile suckers can be easily executed, preventative practices to reduce future issues should also be integrated into landscape management plans. In the case of mechanical wounding, efforts to avoid equipment getting too close to the trunk should be employed. Mulching provides many benefits in the landscape such as moisture retention, temperature moderation and of course, aesthetics; however, the delineation between turf and mulched planting beds provides a visual guide for starting/stopping mechanical maintenance. The presence of mulch also can help suppress weed and turf growth around the trunk reducing the need to string-trim around it in the first place. For larger, mature trees, it is wise to scout the area and observe roots emerging from the ground surface, which can easily be several feet away from the trunk. Expanding the mulch ring diameter or incorporating groundcover plantings can provide a buffer zone so tools or equipment do not get too close for comfort. Near newly planted tree trunks, metal caging or a plastic tree guard can provide protection from wildlife or string trimmer damage. For new trees that are staked, a built-in buffer from mowers is already provided; however, careful string trimming is still necessary.

Maintaining a sucker-free tree may not always be an achievable goal; however, problems can be minimized by following best management practices. It starts with proper planting practices, continues with long-term care, and is maintained through proper maintenance practices. Avoid string trimming or mowing too close to tree trunks, as this can cause wounds that spur suckers and invite other issues. Mulching, groundcovers or protective fixtures represent a functional, aesthetic action you can take in your landscape to protect your trees from suckers induced by mechanical damage. While preventive practices help, maintain a clean look in the landscape by removing suckers as they appear.

For more information on maintaining trees in the landscape, contact your local LSU AgCenter Extension office or visit www.LSUAgCenter.com

P4057
6/3/26
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