Cotinus coggygria 'Royal Purple' Smoke bush Royal Purple is an outstanding specimen, and are a great choice for massing or for hedges. They need minimal pruning to maintain a healthy framework, or alternatively, may be cut back to produce large, dramatic foliage. Royal Purple grows best in moderately fertile, moist but well-drained soil in full sun or partial shade. Drought tolerant. Grows to approximately 3m in height and 3m in width.