One of the few purple-foliage shrubs hardy in cold winter regions, purple sand cherry (Prunus x cistena) adds visual contrast to mixed garden borders and landscape compositions overwhelmed with green shrubs. Best grown in USDA hardiness zones 2 through 8, this fast-growing plant tends to lose vigor and health after 10 years of growth.
A hybrid plant developed by horticulturists, purple sand cherry's lineage involves sand cherry (Prunus pumila) and the purple Myrobalan plum (Prunus cerasifera 'Atropurpurea').
Upright in habit, the primary ornamental qualities comprise foliage and flower. In mid-spring, new leaves unfurl bright burgundy just before the fragrant, very pale pink flowers appear. Once flowers wane, the oval foliage reaches maturity, glossy and dark purple-burgundy. This dark color fails to fade in the intense sunlight or heat across summer. By autumn, more hints of copper appear in the leaves, and become copper-purple with occasional hints of orange before dropping away.
Grow purple sand cherry in a non-alkaline soil that remains moist but enjoys good drainage. A full sun exposure promotes lush and uniform branching and overall growth habit, receiving at least six hours of direct sunlight daily. Rather adaptable, this shrub tolerates nutrient-poor soils, high summer heat, moderate drought and responds well to harsh shearing or branch pruning.
Being fast-growing, purple sand cherry quickly reaches its mature size of 6 to 12 feet in height and 6 to 9 feet in width. This leads to a short life, usually no more than 10 or 15 years before branches irregularly begin dying, or the repeated onslaught of insect pests, including borers and Japanese beetles, or diseases cumulatively cause the shrub to deteriorate.
From an ornamental perspective, if too much shading of foliage occurs, the desirable dark purplish color wanes to deep green with hints of purple, being significantly drab. Shrubs that never receive maintenance pruning develop leggy, weeping branches and a barren, open crown forms in the plant's center.
In cold winter climates, purple sand cherry provides one of few hardy shrub options with contrasting dark foliage. Potential uses include as an informal hedgerow or regularly sheared formal hedge. Individual specimen plants grow in mixed garden borders among other green-leaved shrubs and perennial flowers. Very old specimens attain a small tree-like appearance if you remove lowermost branches over several growing seasons. The vigorous pace of growth promotes its use in shelter-belts to block winds as well as screening unpleasant or overly public views.