Mahonia is a small fully hardy perennial evergreen shrub native to China with yellow flowers in late winter and early spring. This plant has everything going for it: an elegant, architectural look, evergreen toughness, some drought tolerance, adaptability to substantial sun or shade, and – best of all – large sprays of the brightest, sunniest yellow flowers imaginable, appearing from late November through January.
The genus contains about 70 species of evergreen shrubs, which are rather similar to Berberis – in fact, some botanists would like to unite the genera. Most have deliciously scented flowers, but their prime use is to fill inhospitable sites. It grows well in shade and semi-shade, and prefers medium levels of water.
Mahonia x media. This hybrid group includes a number of notable named garden selections, all similar and equally effective and all with long racemes of fragrant yellow flowers in winter. Leggy specimens can be pruned hard in spring. They include ‘Charity’, which has slender, upright, spreading spikes of very fragrant yellow flowers; ‘Lionel Fortescue’, which has upright plumes of bright yellow, slightly less fragrant flowers; and ‘Winter Sun’, which has dense clusters of bright yellow flowers.
Mahonia aquifolium. Mountain grape holly or Oregon grape, as it is commonly known, has glossy green leaves and racemes of yellow flowers in late winter to early spring. There are a number of cultivars, including the vigorous and low-growing ‘Apollo’, and ‘Smaragd’, which has bronze, netted foliage.
Mahonia japonica. This erect species produces arching racemes of scented yellow flowers from early winter to early spring, followed by blue-purple berries. The selection ‘Bealei’ has more compact flower spikes.
Mahonia lomariifolia. This elegant species is one of the parents of Mahonia x media, which it resembles in some respects, though it is more rangy in habit and slightly less resistant to extreme cold. The racemes of flowers, which smell like lily-of-the-valley, appear from late fall to winter and are followed by bluish, grape-like fruits.