The Sweet Gum tree, Liquidambar styraciflua, is prized for its stately pyramidal form and spectacular autumn foliage, ranging from gold to deep burgundy. This desirable tree presents a challenge with its prolific production of spiky seed pods, commonly called sweet gum balls. These woody, capsule-like fruits, typically one to one-and-a-half inches in diameter, drop throughout the fall and winter, creating a persistent litter problem. The sharp, hard nature of the balls makes them difficult to rake or vacuum, turning lawns and walkways into hazardous surfaces that can cause slips and falls. Managing the annual drop requires immediate cleanup, proactive prevention, and cultural adjustments.
Immediate Cleanup Strategies
Dealing with existing sweet gum balls requires specialized tools that can handle the volume and rigid structure. Standard leaf rakes and brooms often prove ineffective, scattering them rather than gathering them efficiently. Homeowners find success with specialized rolling harvesters, sometimes called nut gatherers, which use flexible tines to scoop the balls off the ground and into a collection basket as the tool is pushed. These devices eliminate the need for constant bending and manual collection, significantly reducing labor.
Another mechanical option is a powerful lawn vacuum, although the balls can sometimes clog the intake and collection tubes. Using a leaf blower to corral the balls into manageable piles before collection can make the process more efficient, particularly across large turf areas. Cleanup is easiest when the ground is slightly damp, such as after a light rain, as this prevents the balls from bouncing away when disturbed. Consistent removal is necessary since the drop period lasts from late summer through early spring.
Chemical Treatments for Fruit Reduction
A long-term, proactive approach involves using plant growth regulators (PGRs) to prevent fruit formation. These hormonal solutions disrupt the tree’s natural cycle by sterilizing the flowers before pollination occurs. The chemical ethephon, sold under brand names like Florel, is a common regulator that releases ethylene gas when applied to the flowers. This gas prompts the tree to abort the flowers, preventing fruit set.
The application of these products is time-sensitive, requiring application during a narrow window, typically one to two weeks in early spring when the tree is in full bloom. Applying the chemical too early or too late will diminish its effectiveness, which usually ranges between 50 and 90 percent reduction in fruit production. For mature, tall trees, complete coverage often necessitates high-volume spraying equipment, making it a task best left to a certified arborist. Arborists may also use trunk injections of other regulators, such as those containing indole butyric acid (IBA), which moves through the tree’s vascular system to kill the developing flowers.
Physical and Cultural Management Techniques
Beyond chemical intervention, several physical and cultural practices can reduce the nuisance. Installing a thick layer of organic mulch, such as wood chips, beneath the tree’s drip line can help cushion the impact and absorb the balls. This ground cover hides the balls from view and makes them less of a tripping hazard. For high-traffic areas, laying down landscape fabric or fine-mesh netting during the primary drop season allows for easier, centralized collection of the pods.
Strategic pruning can also play a role, although it does not stop fruit production. Removing lower branches makes cleanup easier by improving access underneath the canopy for mechanical sweepers and vacuums. Regular mowing of the area, even when the grass is dormant, helps to break down the balls over time, preventing accumulation.
Considering Tree Removal and Replacement
When the annual maintenance burden becomes too great, or if the tree is improperly sited near a walkway or driveway, tree removal is the only permanent solution. The decision to remove a mature sweet gum is significant, involving costs based on the tree’s size and location, often requiring professional services. Before cutting down a large, healthy tree, the long-term benefits of shade and fall color should be weighed against the annual aggravation.
If removal is necessary, several fruitless or nearly fruitless cultivars of Liquidambar styraciflua are available as replacements that offer the same aesthetic benefits without the mess. Cultivars like ‘Rotundiloba’ are known to be entirely fruitless and feature distinctively rounded leaf lobes. ‘Happidaze’ is another popular seedless selection. For landscapes with limited space, the ‘Slender Silhouette’ cultivar provides a narrow, columnar form that is also considered largely fruitless.