These elegant and underappreciated trees are native to the Southeast. Bell-shaped white flowers appear in spring, usually just before the leaves emerge. Medium green foliage turns yellow in fall. Pretty in woodland gardens. Good substitute for dogwood (Cornus) where dogwoods will not grow. Grow best in rich, well-drained, acid soil. Buy container-grown plants, as balled-and-burlapped ones do not transplant easily.
H. carolina (H. tetraptera). CAROLINA SILVER BELL. Moderate growth to 3040 ft. tall, 2035 ft. wide. Clusters of snow white, 12-in. flowers in midspring hang along length of graceful branches. Oval, finely toothed, 2- to 5-in.-long leaves. Four-winged brown fruit hangs on almost all winter. Train to a single trunk when young, or it will grow as a large shrub. Flowers show off to best advantage when you can look up into tree. 'James Laubach' has leaves heavily splashed in gold.
Plants in the Vestita Group, sometimes offered as H. c. vestita, top out at about 30 ft. tall and 20 ft. wide, with larger flowers than those of the species. 'Rosea' has light pink flowers.
H. diptera. TWO-WINGED SILVER BELL. Zones US, MS, LS, CS; USDA 6-9. To 2030 ft. tall and wide, usually multitrunked. Oval leaves, pointed at the tip. Flowers resemble that of H. carolina, but they are more deeply lobed and bloom a week or two later, just after leaves emerge. Fruit is similar to that of H. carolina but has two rather than four wings. H. d. magniflora, the showiest silver bell, has larger flowers and is a more profuse bloomer.
H. monticola. MOUNTAIN SILVER BELL. Similar to and sometimes listed as H. carolina. Monticola Group. Plants are larger, eventually to 6080 ft. tall and at least half as wide. Leaves are also bigger (36 in. long), but tree casts only moderate shade. Flowers and fruit are also somewhat larger.