If you've ever seen a tree that was so colorfully decked out in fall colors that it made you stop and say, "wow," then you've probably seen a sweetgum tree.
Sweetgum, Iquidambar styraciflua, is a deciduous species native to North America and most well-known for its star-shaped leaves that put on truly spectacular displays in the fall. Growing up to 50 feet tall, these trees make an impressive addition to gardens with a lot of space to fill.
Like all trees, sweetgum is slow-growing and best bought already started, from a garden center. Nurseries sell trees based on size or age; larger, older trees are more expensive but will require less care to thrive.
Trees will come in either a gallon garden center pot or with a root wall wrapped in cloth and will need to be supported on the ride home to ensure no branches are damaged.
After you're selected a location for your sweetgum tree, dig a hole slightly wider than the pot or root ball that came with your tree. Place the tree in the hole and ensure the root ball is level with the top before backfilling it with enough soil to cover the roots, but not so much that it becomes compacted.
Water the tree and use a tree stake to support your sweetgum and protect it from wind damage.
Sweetgum prefers areas of full sun; however, that doesn't mean they need wide open spaces. In fact, a young sweetgum tree will benefit from a little bit of a windbreak, as strong winds can snap tender branches. A snapped branch won't faze a mature tree, but a newly planted tree might not be able to cope with the damage.
Choose a location that's far away enough from other trees and buildings to avoid shade but close enough to blunt some of the strongest winds.
After planting and for the first year or two after, your sweetgum tree will need to be watered regularly during dry periods or in extreme heat.
Regular rainfall will be sufficient to keep it healthy once established. Of course, if you have some extra time on your watering rounds, giving your sweetgum tree a drink every once in a while will not harm it.
If you're looking for a type of tree that is largely set-it-and-forget-it, sweetgum fits the bill. It prefers planting in rich, acidic soil, and care should be taken to ensure a proper environment when first planting.
After that, yearly fertilizing is not needed, but treating your sweetgum to good general-purpose fertilizer or compost mix every other year may help encourage growth.
As a North American native, sweetgum thrives in many parts of the continental U.S. The trees grow best between zones five to nine, which means that Midwestern gardeners will need to sit this one out, but gardeners in plenty of other regions can enjoy sweetgum's many aesthetic benefits.
Sweetgum does not require regular pruning to maintain its health. Removing dead leaves and branches can be done without damaging the tree, but it's not required.
If you want to shape your tree or control its growth to keep it more compact, cut off suckers and unwanted branches in the spring to shape the tree as desired.
A mature sweetgum tree requires no winter prep, but young trees will need a little help to survive frigid winters. In late fall, spread a layer of mulch 2 feet around the tree's base, careful to keep a 2-inch gap between the mulch line and the trunk to promote air circulation. If you live in an area with abundant wildlife, add tree guards to prevent hungry critters from bark stripping.
If you want to grow more trees without another trip to the garden center, you'll need to plant from sweetgum seeds, as cutting and splitting is not an option with this plant.
In the fall, gather and dry the fruits until they split and spill their seeds. Stratify the seeds in the refrigerator for at least a month before planting in an acidic seedling mix. Seedlings will be strong enough to plant in the garden the following fall.
Cercospora is the disease most likely to infect sweetgum trees. This fungal disease produces dark brown spots on both sides of the leaves. It can cause leaf drop, but it's not usually deadly to sweetgum and is easily treated with an antifungal spray and the regular removal and destruction of infected leaves.
Several pests can infest a sweetgum tree, ranging from bothersome to deadly. Scale and fall webworms are unsightly but not dangerous and can be easily handled with commercially available pest sprays.
A more serious threat to your sweetgum's health is the plum borer, a moth larvae that burrows into the tree and can destroy branches on young trees. Apply an insecticidal spray two to three times a year to remove plum borer larva if the infestation threatens your tree's health.
With its exuberant fall colors and imposing stature, Sweetgum begs to be shown off. These trees can grow up to 8 feet around, so make sure not to plant them too close to structures or other plants. The impressive tree makes a great addition to the tree line but really shines as a stand-alone feature in the front yard.
If you can't find a sweetgum tree near you, there are a few other options that might be a good substitute. The sycamore tree grows to great heights and puts on a beautiful show in the fall, similar to the look and size of sweetgum.
The autumn blaze maple, named for the fiery red color of its leaves in the fall, is a bit more compact than sweetgum but can be grown in much colder temperatures.
The sweetgum tree is safe for children and pets, but all that beautiful fall foliage comes at a price. The bountiful leaves eventually fall and, if not raked regularly, can be a breeding ground for fungus and bacteria that could damage your tree.
So before you commit to putting sweetgum in your yard, make sure you have a strong rake or are prepared to shell out a couple of bucks to the neighborhood kids regularly.
Sweetgum comes in a whole host of varieties to suit any gardener's needs. The Andrew Hewson has uniquely shaped leaves that run the entire gamut of fall colors, from bright yellow to deep purple.
If you have a smaller space to work with, the golden treasure variety grows slowly and matures to a lesser height than the common sweetgum. The Lane Roberts varietal's leaves skew darker and are said to look like the embers of a fire in the fall.