At a glance
| Botanical name | Liquidambar styraciflua |
|---|---|
| Family | Altingiaceae (formerly Hamamelidaceae) |
| Native range | Connecticut south to central Florida and eastern Texas, west to Missouri, Arkansas and Oklahoma, north to southern Illinois; scattered in Mexico and Central America |
| USDA zones | 5–9 (NC State Extension, Virginia Cooperative Extension) |
| Mature height/spread | 60–75 ft tall, 35–50 ft wide (UF/IFAS); NC State lists up to 100 ft |
| Growth rate | Moderate to rapid |
| Light | Full sun to partial shade |
| Soil | Moist, acidic to neutral; tolerates wet soil; chlorosis on alkaline soil |
| Wildlife value | Seeds eaten by goldfinches and many other birds, squirrels and chipmunks; luna moth host |
| Deer resistance | Resistant (Penn State Extension) |
| Drawbacks | Spiky gumball litter, surface roots that can lift paving, large size, chlorosis at high pH |
What a sweet gum tree is
Sweet gum (also written sweetgum, and called American sweetgum or red gum) is Liquidambar styraciflua, a large deciduous tree native to the eastern United States. It belongs to the small family Altingiaceae; older references place it in the witch-hazel family, Hamamelidaceae. Per NC State Extension, the common name refers to the aromatic gum that oozes from wounds, and the name redgum may come from the reddish-brown heartwood of large logs.
Sweet gum is known for three things: glossy, star-shaped leaves; some of the most varied fall color of any native tree, with yellow, orange, red and deep purple often on the same tree; and the spiny seed balls ("gumballs") that drop by the thousands. The USDA Forest Service's Silvics of North America describes it as a moderate- to rapid-growing tree that is intolerant of shade, often pioneers in old fields and logged areas, and ranks as one of the most important commercial hardwoods in the Southeast.
How to identify a sweet gum tree
- Leaves: alternate, star-shaped, usually with five (sometimes seven) long, pointed lobes, glossy dark green with toothed edges, about 3 to 6 inches wide, per the Missouri Department of Conservation. Bruised leaves are slightly aromatic.
- Fruit: a hard, woody, spiky ball 1 to 1.5 inches across, hanging on a long stalk. Each ball is made of numerous tiny capsules, each bearing one or two winged seeds (NC State Extension); it matures in fall and often hangs on the tree through winter.
- Twigs: often develop corky ridges or "wings," most noticeable on young, vigorous branches.
- Bark: brown to gray, very rough, with deep grooves and narrow, slightly scaly ridges on mature trunks.
- Form: pyramidal when young, becoming round to oval at maturity (Virginia Cooperative Extension), with a long, straight trunk.
Sweetgum vs maple
Sweet gum is the tree most often mistaken for a maple, but the two are easy to separate:
| Feature | Sweet gum | Maple |
|---|---|---|
| Leaf arrangement | Alternate (one leaf per node) | Opposite (leaves in pairs) |
| Leaf shape | Star-shaped, lobes long and pointed, finely toothed, glossy | Palmately lobed; lobes and teeth vary by species |
| Fruit | Spiny woody ball on a long stalk | Paired winged samaras ("helicopters") |
| Twigs | Often corky-winged | Not corky-winged |
| Scent | Bruised leaves slightly aromatic | Not aromatic |
The maple identification guide covers the maples sweet gum gets confused with, including red maple. The Missouri Department of Conservation's field guide lists red, silver and sugar maple among sweet gum's look-alikes.
Sweet gum balls: when they form and how to manage them
The gumballs are the reason many homeowners regret a sweet gum. The Forest Service's Silvics account notes that sweetgum begins producing seed at about 20 to 30 years of age and keeps producing until at least 150, with fair crops every year and bumper crops about every 3 years. The fruiting heads mature from September to November, and NC State Extension notes that they litter the ground from roughly December through April.
- Why they are a problem: the Missouri Department of Conservation notes that the balls can clog drains, interfere with mowing, hurt bare feet and make sloping sidewalks hazardous underfoot.
- Cleanup: a stiff rake works on lawns; rolling nut gatherers pick them up quickly from turf and pavement. Do several light cleanups through winter rather than one big one in spring.
- Prevention: plant a fruitless cultivar (below) or place a fruiting tree where the balls fall on mulched beds or naturalized ground rather than paving, play areas or pool decks; MDC notes a mulch bed under the tree helps. For pool-adjacent planting, see best plants for poolside.
Wildlife use: per the Missouri Department of Conservation, the seeds are eaten by goldfinches, purple finches, sparrows, mourning doves, wild turkey, northern bobwhite and wood ducks, as well as by squirrels and chipmunks, and sweet gum is a larval host for the luna moth. Leaving a fruiting sweet gum in a naturalized corner turns the litter into a food source; see plants for attracting songbirds.
Fruitless and other sweet gum cultivars
| Cultivar | Key trait | Best use | Source |
|---|---|---|---|
| 'Rotundiloba' | Rounded leaf lobes; fruitless; narrower than the species | Lawns, patios, streetside where litter matters (zones where it is cold hardy) | University of Arkansas Extension; Purdue Arboretum; UF/IFAS |
| 'Festival' | Narrow and upright; yellow, red and orange fall color | Tighter spaces; still produces fruit | Virginia Cooperative Extension |
| 'Burgundy' | Purplish fall leaves | Fall color specimen; still produces fruit | Virginia Cooperative Extension |
| 'Gumball' | Dwarf, about 15 ft, purple-red fall color | Small-scale specimen | NC State Extension |
'Rotundiloba' is the cultivar to ask for when people say "fruitless sweetgum." The rounded lobe tips make it easy to verify at the nursery, and Virginia Cooperative Extension notes that it may occasionally revert, so prune out any branches with pointed leaves. Know its limits before planting: the University of Arkansas Cooperative Extension Service reports it is cold hardy only to about -10°F and can winterkill north of St. Louis, reaches about 50 feet, and has a more open, free-form habit than the species; Purdue Arboretum adds that good branching is hard to establish on young trees, and recommends northern stock for use in the North. Buy it by cultivar name from a reputable grower, since a seedling sweet gum with the regular pointed lobes will fruit.
Where sweet gum grows well
Sweet gum is native from Connecticut south through the East to central Florida and eastern Texas, west to Missouri, Arkansas and Oklahoma and north to southern Illinois, with scattered populations in Mexico and Central America, per the Forest Service's Silvics account. NC State Extension, Virginia Cooperative Extension and Penn State Extension all list it for USDA zones 5 to 9. UF/IFAS gives a typical landscape size of 60 to 75 feet tall and 35 to 50 feet wide; NC State lists heights up to 100 feet.
| Condition | Sweet gum response |
|---|---|
| Full sun to partial shade | Grows in both (NC State, Penn State); the Forest Service classes it as shade-intolerant in forests |
| Moist, deep, slightly acidic soil | Ideal |
| Wet or periodically flooded soil | Tolerant; Penn State Extension profiles it as a rain garden tree for wet to moist zones |
| Alkaline (high-pH) soil | Prone to iron chlorosis (yellow leaves with green veins), per UF/IFAS and Virginia Cooperative Extension |
| Narrow tree lawns and small yards | Poor fit: large size, surface roots, litter |
If leaves turn yellow between green veins on alkaline soil, the cause is usually micronutrient chlorosis rather than disease; see iron vs nitrogen chlorosis. Wet-site companions are compared in rain garden plants.
Roots, siting and structural issues
Sweet gum is a large tree with a vigorous root system, and its main siting problems are at ground level.
- Surface roots: University of Florida's IFAS fact sheet warns that sweet gum's large, aggressive roots may lift curbs and sidewalks and can form large surface roots, so it should be planted well away from paving. NC State Extension describes a shallow root system, and Virginia Cooperative Extension says the tree does not tolerate sites where its roots lack ample room to spread.
- Size: a tree that reaches 60 to 75 feet tall and 35 to 50 feet wide needs open ground. Plant it where the full crown fits without overhanging the roof or crowding the foundation, and never under power lines.
- Litter: keep fruiting trees away from walkways, patios, driveways, decks and pools.
- Structure: early training to a single leader pays off; the University of Arkansas notes that young fruitless trees in particular need pruning for the first few years to develop a strong branching system.
University of Tennessee Extension's guide to "sewer-safer" trees lists sweetgum among the large, aggressive-rooted trees not recommended near wastewater pipes and advises keeping any tree more than 10 feet from sewer lines. Plan for the full mature canopy spread and keep paving out of the root zone. For trees that stay under 30 feet, see trees for small yards.
Planting and care
- Choose the plant. Pick 'Rotundiloba' wherever gumballs would be a nuisance; a seedling or standard tree is fine for naturalized areas.
- Site it in full sun in moist, acidic to neutral soil with room for a 35 to 50 foot crown.
- Plant at the correct depth, with the root flare at or slightly above grade; follow how to plant a tree.
- Plant in spring and water through establishment. Virginia Cooperative Extension notes sweet gum is slow to establish because of its fleshy roots and recommends spring planting of balled-and-burlapped trees; NC State adds that roots take three to four months to recover from transplanting.
- Mulch a wide ring, kept off the trunk, to reduce mower contact with surface roots.
- Prune in the dormant season to keep a single leader and remove crossing or low limbs.
- Test soil pH before fertilizing. Yellowing on alkaline soil is a pH problem, not a fertilizer shortage.
Fall color
Fall color is sweet gum's biggest selling point. NC State Extension describes leaves turning bright red, purple, yellow or orange that remain on the tree for a long time, and the Missouri Department of Conservation notes that several shades often appear on the same tree. Regional rankings of sweet gum against other fall-color trees are in best trees for fall color.
Pests and diseases
Sweet gum has relatively few serious pest problems; the Missouri Department of Conservation calls it relatively free from insect pests and disease in landscapes. UF/IFAS lists bagworm, fall webworm and leaf miner among occasional insects and names canker diseases as the main disease concern, with leaf spots generally minor. Virginia Cooperative Extension says scale insects are the most common insect pests. Chlorosis on high-pH soil is a common cause of a sickly sweet gum in landscapes, per UF/IFAS.
Wood, uses and firewood
Is sweet gum a hardwood? Yes. It is a broadleaf hardwood; the Forest Service's Silvics account lists lumber, veneer, plywood, slack cooperage, railroad ties, fuel and pulpwood as its main uses, and the Missouri Department of Conservation notes its lumber has been used for cabinetry, furniture, flooring and interior finish.
Is sweet gum good firewood? It is usable (the Forest Service lists fuel among its uses), but it is not a premium firewood. Utah State University Extension's wood heating guide explains that denser wood holds more heat per cord and recommends dense woods such as oak, hard maple and ash. Split and season sweet gum well before burning.
Is sweet gum invasive? Not in its native range in the eastern US, where it is a native pioneer tree. It does seed readily into open, disturbed ground, so seedlings can be numerous near fruiting trees.
Common mistakes
| Mistake | Why it matters | Do this instead |
|---|---|---|
| Mistake | Why it matters | Do this instead |
| Planting a fruiting sweet gum beside a patio, walk or pool | Spiky balls drop for months and roll underfoot | Plant 'Rotundiloba' there, or site fruiting trees over beds and naturalized ground |
| Planting in a narrow strip between paving | Roots can lift sidewalks and curbs, per UF/IFAS | Give it open ground sized for a 35–50 ft crown |
| Planting on alkaline soil without testing pH | High pH causes chlorosis and poor growth | Test soil; choose another species on alkaline sites |
| Buying an unnamed seedling when you want no fruit | Seedling sweet gums fruit once mature | Buy 'Rotundiloba' by name and check for rounded lobes |
| Mowing over gumballs | Gumballs interfere with mowing, per the Missouri Department of Conservation | Rake or use a nut gatherer before mowing |
Frequently asked
What does a sweet gum tree look like?
Sweet gum is a large, pyramidal to oval tree with glossy, star-shaped leaves that have five to seven pointed lobes. It drops spiky, woody balls 1 to 1.5 inches across, often has corky wings on its twigs, and turns yellow, orange, red and purple in fall.
What is a sweet gum tree good for?
Sweet gum provides shade, outstanding fall color, wet-soil tolerance and seeds eaten by goldfinches and many other birds, squirrels and chipmunks. Its lumber has been used for cabinetry, furniture, flooring, veneer and plywood. Fruitless cultivars give the same shade and color without the litter.
Is sweet gum a maple?
No. Sweet gum is in the Altingiaceae family, while maples are in the genus Acer. Sweet gum leaves are alternate and star-shaped with spiky ball fruit, while maple leaves are opposite and maples produce winged samaras.
When do sweet gum trees produce balls?
Sweet gum trees usually start producing seed at about 20 to 30 years old, according to the USDA Forest Service. The fruiting heads mature from September to November, and the empty balls drop through winter, littering the ground from roughly December to April.
Is there a sweet gum tree without balls?
Yes. 'Rotundiloba' is a fruitless cultivar with rounded leaf lobes, profiled by University of Arkansas Extension. It is cold hardy only to about -10°F, so it can winterkill in the colder end of sweet gum's range. Buy it by name, since ordinary seedlings will fruit once mature.
Is sweet gum good firewood?
It is usable but not a premium firewood. The Forest Service lists fuel among sweet gum's uses, while Utah State University Extension recommends dense woods such as oak, hard maple and ash for the most heat per cord. Split sweet gum and let it season fully before burning.
Where do sweet gum trees grow?
Sweet gum is native from Connecticut south to central Florida and eastern Texas, west to Missouri, Arkansas and Oklahoma and north to southern Illinois, with scattered populations in Mexico and Central America. It is planted in USDA zones 5 to 9 and grows best on moist, slightly acidic soil.
Are sweet gum trees invasive?
No, not in the eastern US, where sweet gum is a native tree. It is a pioneer that seeds readily into open or disturbed ground, so seedlings can be common near a fruiting tree, but it is not listed as invasive there.
Sources
- Sweetgum (Silvics of North America), USDA Forest Service
- Liquidambar styraciflua: Sweetgum (ST358), University of Florida IFAS Extension
- Liquidambar styraciflua, NC State Extension Gardener Plant Toolbox
- Sweetgum (Liquidambar styraciflua), Virginia Cooperative Extension
- Plant of the Week: Sweetgum, Fruitless, University of Arkansas Cooperative Extension Service
- Liquidambar styraciflua 'Rotundiloba', Purdue Arboretum Explorer
- Rain Garden Plants: Sweetgum, Penn State Extension
- Sweet Gum field guide, Missouri Department of Conservation
- Wood Heating, Utah State University Extension Forestry
- Choosing "Sewer-Safer" Trees (SP628), University of Tennessee Extension (via UT Municipal Technical Advisory Service)