Sarcococca confusa, sweet box, is a slow-growing evergreen shrub of uncertain wild origin — likely Chinese, though the exact source population has never been confirmed, hence the species name "confusa" — grown almost entirely for one trick: tiny, easily overlooked white flowers that open along the stems in the dead of winter and perfume an entire garden path or entryway with a sweet, honeyed scent far out of proportion to their size. Glossy, dark green, pointed leaves hold their color and shine year-round, and the flowers are followed by small black berries that persist into the following season.
It is one of the most reliable evergreen shrubs for deep shade, thriving in the dry shade under trees and against north-facing walls where few other broadleaf evergreens perform, and it tolerates urban pollution and root competition well. Once established it needs very little water or care — light shaping after flowering, if needed, is the only routine maintenance, and it slowly suckers to form a dense, low colony rather than needing division or replacement. Its combination of shade tolerance, deer resistance, and winter fragrance makes it a mainstay near doorways, along shaded walkways, and under the canopy of larger shade trees.
Root rot
Plants wilt, yellow, and stunt even in moist soil; lower stems and roots turn brown, soft, and mushy and the plant may collapse. Most common in heavy, wet, or poorly drained ground.
Improve drainage and stop overwatering, and never plant too deep. Lift and destroy badly affected plants along with the soil around the roots. Grow in raised or free-draining beds to prevent it returning.
Fungal leaf spot
Brown or purplish spots on the leaves, often ringed with a yellow halo, that spread and merge in warm, humid, or wet weather; heavily spotted leaves yellow and drop early.
Pick off spotted leaves and clear fallen debris to remove overwintering spores. Improve air circulation by thinning, and water at the base so foliage dries quickly. If it persists, apply a copper- or sulfur-based fungicide at the first sign.