Prized for their beautiful foliage, these fast-growing plants are also famously drought tolerant. Most are native to Australia. Lack of cold hardiness limits their use in the South. Sudden freezes or hard winters may kill fairly large trees to the ground or kill them outright. For this reason, some Southerners grow them as annuals or herba- ceous perennials for summer color. Still, some species are surprisingly hardy; they are listed here. None is bothered by deer.
Outside of prime eucalyptus territory, you may wish to try your hand at growing the plants if you enjoy experimenting. Plants are easily started from seed; most grow very rapidly, perhaps as much as 1015 ft. in 1 year. Some are large trees with great skyline value; some are medium to large shrubs or multitrunked trees. Most bear small white or cream owers that are conspicuous only in masses, while others have colorful, showy blooms. Some have leaves of unusual form, highly valued in oral arrangements. Nearly all have foliage that is aromatic when crushed. Most have two different kinds of leaves; those on young plants or new growth differ markedly from mature foliage.
The sizes listed for trees below apply to plants grown in the Coastal and Tropical South; plants grown elsewhere are unlikely to reach such heights. Hardiness gures are not absolute. In addition to air temperature, you must take into account the plant's age (generally, the older the hardier), its condition, and the timing of the frost (24F following several light frosts is not as dangerous as the same low temperature following warm autumn and winter weather). Consider any eucalyptus a risk; occasional deep or prolonged freezes can kill even large trees. If you are committed to growing eucalyptus, don't hasten to remove apparently dead trees; although their appearance may be damaged, they could resprout from trunk or main branches.
E. cinerea. SILVER DOLLAR TREE. Zones LS, CS, TS; USDA 8-11; grow as annual in Upper South and Middle South. Hardy to 1012F. Small to medium tree of irregular habit; grows 2050 ft. tall and nearly as wide. Grown for attractive juvenile foliage, which is popular in floral arrangements; paired, gray-green to blue-green, nearly round, 1- to 2-in.-long leaves. Mature leaves are green, narrow, up to 4 in. long. Unimportant small white flowers. Cut back often to maintain a good supply of young foliage. Recovers from freezes if base of trunk is heavily mulched.
E. gunnii. CIDER GUM. Zones MS (protected), LS, CS, TS; USDA 7-11. Hardy to 510F. Dense form; upright, medium to tall treeto 3070 ft. tall, 1840 ft. wide. One of the fastest-growing eucalyptus. Silvery blue-green, oval to roundish young foliage; dark green, narrowly oval, 3- to 5-in.-long mature leaves. Small, creamy white flowers.
E. neglecta. OMEO GUM. Zones MS, LS, CS, TS; USDA 7-11. Hardy to 0F. Shrubby, fast-growing, small to medium tree to 20 ft. tall and 12 ft. wide (or larger). Handsome round, blue-green, paired juvenile leaves to about 2 in. long; excellent for cutting. Mature leaves are more oval in shape; they retain the attractive color of the juvenile foliage. Good-looking brown, peeling bark. Unimportant white flowers.
E. pauciflora niphophila (E. niphophila). SNOW GUM. Zones MS, LS, CS, TS; USDA 7-11. Hardy to near 0F. Small, picturesque tree to 20 ft. tall, with wide-spreading, open habit. Oval, pointed young leaves are gray-green, to 23 in. long. Lance-shaped, silvery blue adult leaves reach 4 in. long. Smooth, peeling white bark on trunk contrasts handsomely with red branches.
E. torelliana. CADAGA. Zones TS; USDA 10-11. Hardy to 2830F. Straight-trunked tree with rounded or spreading form; grows fast to 4560 ft. tall. Juvenile leaves are 24 in. long, broadly oval; mature leaves are dark green, 36 in. long, narrower and more pointed. Profuse display of showy white flowers. Regular water. Often grown in south Florida.