If you live in the southeastern United States up into New York, you might encounter trees that shed spiky balls. These woody balls litter the area around each tree, creating a nuisance for pedestrians, bicyclists and skaters. They can also damage lawnmowers if you fail to clear them away prior to mowing. The culprit that sheds these pods is Hamamelidaceae Liquidambar styraciflua L, or the sweet gum tree.
Sweet gum trees do not produce the spiky seed pods until they are at least 20 years of age, according to the USDA Forestry Service. When they do produce these spiky pods, the pods mature between the months of September to November. The pod first develops as a vibrant green ball with flexible spikes. As it matures, the colour turns brown, and the beaklike spikes become pronounced. The pods endure throughout the winter and fall in the early spring after new foliage sprouts. Each ball has two separate seed pods, and each ball contains 20 to 30 seeds. When the woody balls fall to the ground, they may clump together in yards and on sidewalks, creating a tripping hazard.
Sweet gum trees are considered a "pioneer" species because they are often the first trees to repopulate an area after logging or clear cutting. Sweet gum thrives in the moist soils of bottomland valleys and low, sloping locations. It is one of the most adaptable of the hardwood trees due to its ability to grow in a wide range of soil conditions. It thrives best, however, in the alluvial clay and loamy soils of river bottoms. Examples of regional growth performance show that in Maryland it performs poorly in nonalluvial clay or gravelly clay, while in the lower Mississippi Valley, it does well in medium-texture soils with moderate to good internal drainage. Mature trees require direct sunlight and do not tolerate shade well. Saplings, however, will grow in shady areas, but will falter as they get older if they can't access sufficient sunlight.
The sweet gum tree grows tall and straight. It has a distinctive trunk with grey bark that is deeply furrowed. Mature trees reach heights of 80 to 150 feet. The trunk may grow up to 3 feet wide. The dark green leaves have five points and, when crushed, emit a pleasant scent. This characteristic is what gives the sweet gum its name. The tree develops its root system according to soil conditions. If the soil is well-drained, the root system runs deep. In marshy areas, the roots run shallow and close to the surface.
Sweet gum is a durable hardwood. As such, it is particularly useful in a variety of ways that require longevity. Sleepers, lumber for housing, furniture and flooring are all products of the sweet gum tree. When clustered around the base of garden plants, the spiky balls make a good slug and pest deterrent. Save the empty balls until the next growing season, and use them as a dog and cat deterrent. The balls also help aerate the soil due to their long decomposition time. Use them in the bottom of planters, or mix them in with soil when you prepare it for planting.