Sweetgum (Liquidambar styraciflua): what the agencies record

This page reports what US federal publications say about one tree. It does not identify trees from descriptions or photos and does not say what should be done with any tree. The family overview, tree species in the agency records, explains the sources and holds the comparison table.

At a glance

Item	What the source records
Scientific name	Liquidambar styraciflua L., witch-hazel family
Other names	Redgum, sapgum, starleaf-gum and bilsted (Silvics)
Native status, USDA PLANTS	Native in the lower 48 states; the profile lists no native status in Canada
Growth rate, Silvics	Moderate to rapidly growing
Green weight of the wood, NRS-38	50 lb per cubic foot, without bark

Native range

The Silvics of North America handbook (Agriculture Handbook 654, 1990) says sweetgum grows from Connecticut southward throughout the East to central Florida and eastern Texas, as far west as Missouri, Arkansas and Oklahoma, and north to southern Illinois. It also records scattered locations in northwestern and central Mexico, Guatemala, Belize, Salvador, Honduras and Nicaragua. The handbook calls it a common bottom-land species of the South that grows biggest and is most abundant in the lower Mississippi Valley, and one of the most important commercial hardwoods in the Southeast. It says the tree often pioneers in old fields and logged areas in the uplands and Coastal Plain and may develop in a nearly pure stand.

Crown habit and growth

Silvics says young sweetgum have a strong excurrent growth habit and long, conical crowns that usually prune themselves readily under forest conditions. At a definite stage in development, depending on site quality, the tree becomes decurrent as it matures, and the crown becomes rounded and wide spreading. The tops of overmature trees are usually broken or stag headed. The handbook reports average 10-year diameter growth of 4.8 cm (1.9 in) for overmature sweetgum in the southern region and 8.9 cm (3.5 in) for immature trees of medium to high vigor.

Flowers and seed

The handbook says sweetgum is monoecious, with small greenish flowers that bloom from March to early May depending on latitude and weather, both sexes in heads. Seeds are held in balls. Scientists at the Forest Service's Forestry Sciences Laboratory in Athens, Georgia expect 20 to 30 sound seeds per ball in an average year, and as few as 5 per ball in a bad year. The maximum seed dispersal distance recorded is 183 m (600 ft), and ordinarily 96 percent of the seed falls within 61 m (200 ft) of the point of release.

Roots

Silvics says early root development varies with site. On well-drained bottom-land sites a deep taproot with numerous well-developed laterals usually develops rapidly. On wet sites with poor drainage the root system is shallow and wide spreading, with little taproot. On gravelly ridges, hillsides and upland Piedmont sites it develops a particularly strong taproot and is very resistant to wind.

Wood

The Wood Handbook (FPL-GTR-282, 2021) says the lumber is usually separated into sap gum, the light-colored sapwood, and redgum, the reddish-brown heartwood. It adds that sweetgum often has interlocked grain and must be dried slowly. When quartersawn, interlocked grain produces a ribbon-type stripe the handbook calls desirable for interior woodwork and furniture. The wood is moderately heavy, hard, strong and stiff, with moderately high shock resistance. The handbook says almost all lumber is produced in the Southern and South Atlantic States.

Wood Handbook figure	Green	At 12% moisture content
Specific gravity (Table 5-3b)	0.46	0.52
Modulus of rupture, lbf per square inch (Table 5-3b)	7,100	12,500
Side hardness, lbf (Table 5-3b)	600	850

The green weight of the wood is in the NRS-38 table, the same figure used in the log weight calculator.

Pests and diseases the handbook names

Silvics (1990) says few severe diseases are associated with sweetgum.

Decay. The four most common decay organisms reported in the Mississippi River Delta were Fomes geotropus, Pleurotus ostreatus, Lentinus tigrinus (as the handbook prints it) and Ganoderma lucidum. In that delta, 42 percent of sweetgum burned once showed decay 8 years later, and 79 percent of trees burned repeatedly during an 8-year period.
Sweetgum blight. A leader dieback the handbook says is widely distributed and has caused heavy mortality in several states, with drought appearing to be the primary cause. It also names a twig canker and trunk lesion from Botryosphaeria ribis, and bleeding necrosis.
Insects. Except for leaf feeders, insects usually attack only trees that are already damaged, decadent or dead: the bark beetles Dryocoetes betulae and Pityophthorus liquidambarus, the ambrosia beetle Platypus compositus and darkling beetles. The leaf feeders it names are the forest tent caterpillar and the luna moth.
Animals. Hogs, goats and cattle on seedlings; mice and rabbits on young plantations; and beavers in the Georgia Piedmont, which it says cause impoundments and girdle healthy trees.

The handbook also says fire may be one of the major agents of damage and that summer fires damage young sweetgum more than winter fires. The guide on reporting a pest in the United States gives the office that takes sightings of regulated pests, and pests and diseases by country sets out which ones agencies regulate. Who may apply pesticides is in pesticide licences by country.