Chosen as an improved selection in Ireland in 1966, Winter Sun mahonia made its way south to the Carolinas as a relative newcomer, bringing a more compact habit and more intensely fragrant flowers than the common leatherleaf mahonia it resembles. Its coarse, holly-like foliage gives the plant year-round structural presence, but it is the December flowering that defines it — bright yellow spikes held above the dark leaves like lanterns in a bare garden, a display that earns the cultivar name completely.

Even with its improved compactness, an unpruned plant will reach eight feet in time, so the gardener who wants it smaller should plan for light shaping rather than hoping it stays contained. Mulching the root zone is particularly important: it protects against winter cold and retains summer moisture during droughts, which can otherwise stress the plant noticeably. The robin's-egg-blue berries that appear in late spring in grape-like clusters are an added pleasure and draw songbirds reliably. Grow it in partial shade with protection from wind, and give extra water during dry summer stretches.