Elderberry plants belong to the genus Sambucus, a group of deciduous woody species whose classification often confuses gardeners. The plant’s growth habit is highly flexible, exhibiting characteristics of both a multi-stemmed shrub and a small, single-trunked tree. This ambiguity stems from the genus’s natural tendency to produce multiple stems from the base, meaning the plant’s ultimate size and form vary significantly depending on the species and how it is managed.
The Botanical Classification: Shrub or Small Tree
Botanically, most elderberry varieties are categorized as woody deciduous shrubs, defined by their tendency to grow multiple canes directly from the ground. The American elderberry (Sambucus canadensis) typically grows as a dense, multi-stemmed shrub, reaching 8 to 12 feet in height. This species rapidly forms thickets by sending up new shoots, known as suckers, from its root system, maintaining its shrub-like appearance through the continuous cycle of new cane growth.
The ambiguity arises with the European elderberry (Sambucus nigra), which can develop into a much larger form, reaching 15 to 20 feet. This species is often described as a small, short-trunked tree. While the American variety maintains a classic shrub form, the European variety can be trained to grow with fewer, thicker main stems, giving it a more tree-like silhouette. Ultimately, all elderberries are naturally multi-stemmed, but their potential size dictates their classification.
Key Identifying Features
Elderberry plants possess several distinctive characteristics that aid in identification. The leaves are a primary identifier, growing in an opposite arrangement along the stem. Each leaf is compound, divided into five to eleven smaller, lance-shaped leaflets with finely serrated edges.
The flowers appear in large, flat-topped clusters known as cymes or corymbs, often measuring 4 to 10 inches wide. These clusters consist of numerous tiny, creamy-white flowers. Following the bloom, the fruits develop into small, pea-sized berries that are usually dark purple or black when ripe.
A definitive botanical feature is the spongy material found inside the stems and twigs. When a young branch is cut open, it reveals a thick, soft, white or tan pith at its core. This soft pith differentiates elderberry from many other woody plants. The bark on older stems also becomes distinctively gray-brown, developing shallow, corky fissures.
Managing Elderberry Growth and Size
Since the elderberry is naturally a fast-growing, multi-stemmed shrub, managing its size and shape is an ongoing task. Regular pruning is necessary to maintain a productive fruiting plant and prevent it from becoming an unruly thicket. The most effective method is renewal pruning, which involves removing the oldest canes each year to encourage younger, more vigorous growth.
Cane productivity peaks around three years of age. Removing the oldest stems (three years or older) in late winter or early spring before bud break is beneficial. This practice directs the plant’s energy into newer canes, which produce the best flowers and berry crops. To maintain a compact, bushy form, allow the plant to sucker and remove the oldest canes annually.
If the goal is to train the plant into a more tree-like form, it requires selective pruning over several years. Select one or a few of the strongest, most upright stems to serve as a trunk. Systematically remove all competing suckers and lower side branches to control the plant’s natural tendency to spread widely from the base.