Mahonia is very unusual because it comes into flower in late autumn, as other shrubs shut up shop, and it is all the more valuable for that. It can flower in late autumn and well into late winter, although it looks freshest in the early part of its flowering season.
This great shrub is upright in its growth with cane-like stems that carry dark-green glossy leaves. The evergreen leaves have two rows of leaflets, each one like a holly leaf with pointed spiny edges. At the top of each branch, and nestling in a circle of leaves, is a cluster of upright flower stems.
On each of these stems, dozens of small yellow flowers are carried. These open from rounded green buds, turning yellow when they swell, and opening as tiny daffodil-shaped flowers. It is not related to daffodils, but, strangely, the flowers are not only daffodil-like in shape, but have a sweet daffodil-like scent too.
The best known, and most beautiful, species is Mahonia japonica, native to China, not to Japan as the name implies. It makes a fine bush to about two metres tall and at least as much across. It needs space and would not really suit a small garden. It adds good greenery for winter effect, never too heavy.
The scent of the flowers is best appreciated when some of the flower stems are brought indoors where they will last in water for a few days. The variety 'Bealei' has slightly blue-green leaves and holds its shorter flower spikes more upright.
Mahonia species have been hybridised to give several named varieties. 'Charity' is the best known of these with lots of flower spikes, upright at first and then arching with the weight of flowers as they open. 'Winter Sun' has arching bright yellow flower spikes. 'Lionel Fortescue' has upright, bright yellow flowers, on stems up to 40cm long.
Any of these mahonias is worth growing for its good evergreen foliage and flowers, especially in late autumn and winter, when there is little else in flower. There are spring-flowering mahonias too but the autumn and winter kinds are more useful.
Mahonia likes good soil, but will grow in any ordinary soil that is not wet and soggy, and it survives well in dry soil, though its foliage will not be as luxuriant. It flowers best in good light but can take a fair degree of shade. Mahonia can grow lanky but the tall shoots can be cut back low in spring after flowering and will re-sprout well.