Carolina Silverbell, Halesia carolina

IMG_6112Near the 60 foot climbing tower where I work there is a Carolina silverbell, Halesia carolina.  The tree’s 4-winged fruit and brownish-black bark with sandy-colored streaks was very noticeable on the September day I took these pictures. I saw a showy display of white bell-shaped flowers on the tree late last March, about a week before dogwoods began to bloom. This tree grows in a wooded bottomland area near a stream, but with proper care Carolina silverbells can be grown as great landscape specimens.

Carolina silverbells prefer moist and organically rich soils in part shade, and are intolerant of heat, drought, IMG_6231poor soil, or alkaline pH. Acid soils with pH below 6.5 is best. They are fast-growing and live up to about 100 years, but its wood is relatively weak and soft and does best in areas protected from damage by wind. Usually found on wooded slopes and the banks of streams, they are most abundant in the mountain and upper piedmont areas. Found in the southeastern United States from West Virginia to north Florida and eastern Oklahoma, it is a large shrub or small understory tree that usually does not exceed 35 feet in height. The IMG_6227Atlanta Champion in Lullwater Conservation Park is 3.3 feet in circumference, 57.8 feet in height, and 40.5 feet in spread. This height almost reaches the top of the Inner Harbour climbing tower.

The trunk of the Carolina silverbell is usually 4 to 12 inches in diameter, and has much visual interest. On young trees, the trunk bark is gray to dark gray with somewhat rough texture. The bark has streaks or furrows running in a longitudinal, irregular and interwoven pattern. These streaks or furrows may be pale pink, pale yellow, pale reddish yellow, or white. Mature trees have a pattern of white furrows between IMG_6229gray-brown flat plates that peel. The gray bark on branches is smoother than trunk bark, and also has light-colored furrows. Bark on twigs is usually reddish brown and smooth, and forms slight wings very similar in appearance to winged elm or sweetgum. Young shoots are light green and hairy. Leaves alternate on the shoots and current-year twigs, on leaf stalks that are ¼ to ¾ inches long. They are light green, and hairy when young. These ovate to obovate leaves are about 2 ½ to 5 inches long and 1 ¼ inches across, and their margins are finely IMG_6224serrated. Leaves may be either broader or narrower at the base. On young leaves, the upper surfaces are pale medium green and have some short pubescence. Lower surfaces are whitish green and densely pubescent with the hairs radiating in a star pattern. On older leaves, the upper surfaces are medium to dark green and smooth. Lower surfaces are light green and slightly hairy along the major veins, or smooth. Autumn leaves become greenish yellow, yellow, or yellowish brown before dropping.

The Carolina silverbell can bloom when it is 3 to 5 feet high. It blooms in a showy display for about 2 weeks IMG_6221while spring leaves are developing, in early May. These leaves tend to obscure a clear view of flowers so that often the best view of them is to view closely or from below. Clusters of 2 to 5 flowers hang downward along twigs of the preceding year. They are ¾ to 1 inch long and less than this wide. They are attached to the twig by slender, light green and pubescent pedicels that are ½ to ¾ inches long. Flowers consist of a white bell-shaped corolla that has 4 lobes or petals. The lobes are short, rounded, and often flared outward at the margins. The calyx supporting the petals is less than ¼ inches long, with 4 widely spaced teeth. There is a pistil and 8 to 16 stamens inside, with white filaments and yellow IMG_6278anthers.  The fruit that replaces the flowers are light green until autumn when they turn brown. They mature to be 1 to 2 inches long, ellipsoid, and smooth. They also have 4 wings and slender beaks, which is of visual interest. Fruit persists on the tree after leaves have dropped. Inside each fruit, there is a single stone that can be ½ to 1 inch long.  That stone may contain 4 seeds or 1 seed. Propagation can be by seeds, by layering, by root cuttings, or by greenwood cuttings. Many nurseries carry the tree.

As a landscape specimen, the bark, flowers and fruit of the Carolina silverbell provide visual interest for IMG_7967all seasons. Branches begin low on the trunk, and droop as the tree grows. They may be left that way, or pruned to show the bark better and allow pedestrian and vehicle passage. Roots are usually not a problem, but they may produce new shoots if the trunk is damaged. The tree may be grown as a single trunk or as one having several trunks. A multi-trunk display can be striking when lit from below at nighttime, in a good spot. The fruit having 4 wings and a beak is especially noticeable after leaves drop. The tree mixes well with plants such as rhododendrons and azaleas in the landscape. The tree is not normally bothered by pests, and its flowers attract hummingbirds, honeybees and bumblebees. Squirrels IMG_6117may occasionally eat the sour immature fruits. The tree is winter hardy in zones 5-8, but needs protection from drying, from damaging winds, and from poor or alkaline soils.

I enjoy seeing the Carolina silverbell in landscapes, knowing their natural setting. The wood is light, soft, finely grained, and a favorite of wood carvers. I plan to carve something from a piece one day. This is a good tree to keep an eye out for in low-lying areas of the piedmont.

IMG_6658 (Edited)

IMG_8693 (Edited)

 

IMG_7969

IMG_6254