Gumballs are one of several types of nuisance fruit that grow on trees and can make a mess of your yard and hardscape. The most common are the spike covered, round and brown fruits dropped from the sweetgum tree in the fall and winter. Using pruning to prevent the formation of gumballs would destroy the canopy of the tree and be extremely time consuming. The practical solution is a yearly application of a chemical spray that mimics growth hormones in the plant and can prevent fruit formation from occurring in the first place while preserving foliage and bloom.
Schedule prevention spraying for gumballs in the spring just as the green buds swell on the branches and small leaves begin to unfurl.
Fill a horticultural sprayer with the Ethephon product if not using a product prepackaged in a sprayer. Prepackaged products will be more efficient for small trees but for very large sweetgum trees that can reach 150-feet in height buying Ethepon in bulk and refilling a horticultural sprayer may be more efficient.
Don your respirator face mask to prevent inhalation of the spray and eye goggles or glasses to prevent the mist or overspray from getting into your eyes.
Spray the Ethepon product to cover all or as many of the leaves as possible using a ladder or a cherry picker to reach into the canopy in large gum trees. Apply according to the product label dosing directions making the leaves moist on both sides with the product but not so wet that the product is dripping off of the foliage. The more leaves that are coated the better the control of gumball formation you will have.