Mahonia oiwakensis subsp. lomariifolia

Mahonia oiwakensis subsp. lomariifolia, often simply called Mahonia lomariifolia, may be the most elegant and sculptural of all mahonias. While it is remarkable in winter with its long, fragrant, golden flowering, this large bush also has a very distinctive habit that gives it an exotic and beautiful appearance throughout the year. Its long, evergreen, and glossy leaves, deeply divided into narrow, spiny leaflets, are reminiscent of the fronds of a tree fern. This highly structured plant will bring a touch of exoticism to any setting.

Mahonia lomariifolia belongs to the Berberidaceae family. It is a hardy species (-15°C (5°F) at least) and not very water-demanding, native to China. Its ease of cultivation and ornamental qualities have earned it recognition from the Royal Horticultural Society. This rhizomatous bush reaches a height of about 3m (10ft), slightly less in width. Its growth rate is slow during the early years but then accelerates. Growing on multiple trunks that tend to become bare over time, this mahonia has an erect, gracefully spreading habit supported by sparsely-branched stems. The evergreen foliage is composed of long leaves arranged in rosettes at the end of the stems. Reaching a length of 50cm (20in), they are divided into 10 to 20 pairs of leaflets arranged in an opposite manner along the central vein, on an almost horizontal plane. Each leaflet, lanceolate in shape, has a leathery texture and a spiny, undulate margin. The colour of the young spring foliage is purplish green, becoming dark green in summer with a yellow-green underside. The flowering, long in the heart of winter, extends from late autumn (December) to the middle of winter (January-February). The inflorescences are erect to slightly arched, arranged in rosettes at the end of the young stems. These clusters, measuring 10 to 25cm (4 to 10in), are composed of numerous small, yellow, bell-shaped and nectar-rich flowers. Their fragrance is somewhat reminiscent of lily-of-the-valley, but lighter. They give way to small, decorative blue berries covered with bloom. They are weakly toxic to humans, but appreciated by birds.

Flowering in the heart of winter, with long yellow panicles, the mahonia becomes the focal point in the garden when other plants are dormant. For gardeners in cold regions, it can replace the southern mimosa, to some extent, both in the garden and in bouquets. Its unique, sculptural, and highly structured habit will transform a border or a large shaded rockery. For example, plant it with ferns and the blue flowers of liverworts or bluebells in cool, shaded areas. To conceal the somewhat bare base of the bush, consider perennial geraniums, autumn daisies, or wall germander (Teucrium chamaedrys), which are evergreen and truly undemanding. A group of 3 subjects placed in a triangle will create a quite spectacular grove. If placed at the corner of a patio or porch, it will perfume the air and bring colour close to the house during the dreary days of winter. Gardeners can welcome it in a large container on a patio or balcony, for example, along with dwarf bamboos. This mahonia can also be included in a mixed hedge, with other evergreen shrubs.