788 Viburnum rufidulumCommon Names: rusty black-haw, southern black-haw Family: Caprifoliaceae (honeysuckle Family)
Rusty black-haw is a typical Viburnum in that it is a shrub or small tree with opposite leaves, 5-petaled flowers in rounded cymes, and clusters of shiny blue-black drupes. [A cyme is a branched cluster of flowers in which the central flower opens first and the lateral flowers open in sequence, from the inside out; cymes can be either flat-topped or domed. A drupe is a fleshy fruit containing one (occasionally more) hard stones, each of which contains one (occasionally more) seeds.]
Rusty black-haw is a unique Viburnum in that its leaves are extremely glistening and shiny, and its buds and young stems are clothed with a dense rusty-red pubescence. The glossy leathery leaves are tardily deciduous, oval, almost as broad as long, 2-4 in (5-10 cm) in length, and have patches of rusty pubescence on the petioles (leaf stems) and along the major veins on the leaf undersides. The foliage turns a rich reddish purple in fall. The flower clusters are very showy, 2-5 in (5-12.7 cm) across, and composed of several dozen little creamy-white flowers. The peanut shaped drupes are a lustrous purple or dark blue-black with a waxy bloom, and about a half-inch long. They droop on red stalks and the clusters are sometimes so abundant that they cause the branches to droop under their weight. Rusty black-haw is really a small tree rather than a shrub because it usually grows with a single trunk. It has a slender trunk, an open, irregular or rounded crown, and starts branching close to the ground. Rusty black-haw rarely gets more than 10-15 ft (3-4.6 m) tall, but the national champion in Hempstead City, Arkansas, is 25 ft (7.6 m) tall. Rusty black-haw sends up suckers from the roots, and can form thickets under favorable conditions. 'Royal Guard' is a compact, narrowly upright selection with particularly glossy dark green leaves that turn burgundy to maroon in fall.
Rusty black-haw, Viburnum rufidulum, occurs naturally in southeastern North America from Virginia and southern Ohio, west to Missouri and eastern Kansas, and south to central Texas and northern Florida. It grows in well-drained soils in the understory of upland mixed hardwood forests, and frequently along roads, fencerows and at the edges of fields.
CultureLight: Rusty black-haw grows well in partial shade where it tends to have an open, airy habit. In full sun it grows more dense and bushy. Maximum flowering and fruiting occur in full sun. Moisture: Rusty black-haw is quite drought tolerant. Hardiness: USDA Zones 5 - 9. Propagation: You can expect rusty black-haw to flower every spring, but you may not get fruits if you have only one plant. Like most viburnums, rusty black-haw is self-incompatible, which means that it cannot pollinate itself. To get fruits, you need two different seedling plants - two vegetative clones of the same plant will not suffice. Viburnum seeds are difficult to germinate because they have a required period of dormancy and are enclosed in a hard seed coat or stone. Under the best of conditions, black-haw seeds will take a year to germinate. Clean the stones thoroughly, removing all traces of the fleshy pulp, sow them in potting medium or soil, and leave the pots outside in the weather. Wait. Keep seedlings in the shade for a year or two. Rusty black-haw can be propagated vegetatively from fast growing green-wood cuttings taken in summer.
The leaves of rusty black-haw literally glisten in dappled light, and they highlight the pretty clusters of creamy white flowers. The shiny blue-black fruits, the colorful leaves in fall, and the rusty buds in winter are still more reasons to want this pretty little tree in your landscape. The graceful little rusty black-haw makes a perfect specimen in the dappled shade of a large oak or pine. Use black-haw in the woodland or wildlife garden. The edible fruits are sweet and relished by birds and small mammals.
Rusty black-haw must be one of the best kept secrets in flowering shrubs and small trees. This little tree tolerates dry shade and rewards with showy clusters of white flowers that leap out from the glistening foliage. Rusty black-haw is the southern version of the better known black-haw viburnum (V. prunifolium), only with prettier leaves and larger, showier flower clusters. Other popular native American Viburnums are arrow-wood (V. dentatum) and Walter viburnum (V. obovatum).
Steve Christman 9/3/00; updated 8/11/03