It’s a difficult shrub to notice, since Mahonia is so often planted in neglected corners. Even when it bursts into fluorescent yellow flower, often exuding a sophisticated scent, there is something of the old ancestor about it. However: mahonia’s Gothic limbs come in different shapes and sizes besides the predictable Mahonia japonica and the American native Mahonia aquifolium. A good mahonia can absolutely stop you in your tracks. Could you fall for one?
Read on for five ideas to use Mahonia to best effect in a landscape design:
Photography by Britt Willoughby Dyer, for Gardenista.
Dress Up a Wall
As statuesque as a palm or tree fern, this Mahonia lomariifolia is the work of an imaginative gardener. Protected from exposure by a tall and ancient wall at the Oxford Botanic Garden, it is a choice that anyone with a sheltered garden in USDA zones 8 or 9 could make.
Handsome is as handsome does: the palm-tree effect of Mahonia lomariifolia can be exaggerated by training the vertical branches away from each other, so that the spectacular bursts of flower and foliage are not all jammed together. They set quickly, so a temporary setup of twine would do, while the nursery Architectural Plants suggests using wedges of soft balsa wood.
A Sunny Situation
Mahonia x media, child of Mahonia lomariifolia, is more popular than its parent, being hardy in USDA zones 5 to 9. This hardiness is thanks to its other parent M. japonica, the stubborn resident of shady shrubberies everywhere. In a more sunny position, leaves taken on autumn hues and carry these colors through winter.
Also known as the Oregon grape, the flowers of Mahonia x media are pretty, its leaves graceful. The scent is most often compared with lily of the valley.
To keep the plant robust, its flowers at eye level, it is a good idea to prune Mahonia x media, while thinning out internal branches. This way, it can be repurposed in summer as a structure for temporary climbers, such as late-flowering clematis (instead of growing them up a tripod or worse, a flat wall). They need something three-dimensional to scramble through.
Grand Ground Cover
East meets west: Mahonias are native to North America as well as to China and once, a long, long time ago, they shared the same continent. Nowadays, the American mahonia is used in British car parks and is not given a second thought. At the Oxford Botanic, home to 37 varieties of mahonia, this small shrub with its subtle colors is more than a practical ground cover.
A Golden Glow
Common (or garden) Mahonia japonica, like all of its immediate family, is more than happy to be moved out of the deep shade. The specimen above is at the end of its flowering season but in winter, planted in a grove, Mahonia japonica and Mahonia x media almost glow in the dark, and are highly perfumed. The less desirable mahonia, often confused with the variety shown here, is Mahonia bealei (known as leatherleaf) with foliage that is more truncated and with an unfortunate habit of spreading everywhere.
One of the best things about a good mahonia, and the reason for its “grape” moniker, is the development of flowers to berries. As the yellow drains away, the fruits look elegantly ghostly, white grapes turning into black grapes (and they are edible).
A Graceful Silhouette
And there is another variety, for people who can’t get along with spines, the winsome Mahonia confusa, which only grows to a height of about 5 foot. Pruned for height, with side shoots removed, it is genuinely pretty in a shady corner with poor soil, although you might want to place it where you can really see it.