The root of 3

Handsome and evergreen in appearance, with spectacular, scented flowers, the Holly-leafed Sweetspice, Itea ilicifolia, is a shrub of quality too seldom planted.

Perhaps its reputation for tenderness puts people off. There's no denying that it hates exposure and that icy winds will do it damage. But, given some protection, like that afforded by a warm, sheltering wall, it will survive the majority of British winters unscathed.

Originating from western China, this plant will, in time, reach about 10ft in height and as much across. It has graceful, arching branches, which form a cascade with age, and bright, rounded, glossy green leaves, silvered on their undersides, which have small, sharp spines around their edge, like a holly. It doesn't need pruning, except to keep within limits, and will grow in sun and light shade.

The shrub's display of greenish-cream flowers, fading to greenish-yellow, is a real show-stopper. Individually, each bloom is tiny but they are held in long, pendulous, catkin-like tassels up to a foot or more in length. These are produced in great abundance from the top of the shrub to the bottom, veiling the foliage in a pale-green waterfall of blossom.

Each pendant flowers from the base, opening in sequence as though on a slow fuse and releasing their honey-sweet scent into the air. Itea blossoms in mid to late summer, with its flowers lasting well into the autumn.

The warm spot that you have chosen for the Itea will be well liked by its two companions - the Iris, Iris pallida "Variegata", and the Allium or ornamental onion, Allium aflatunense. Place them at its feet in a generous, intermingling group.

The Iris looks good in front of the Itea, with its contrasting strong, broad, sword-shaped leaves and upright habit. Also, its glaucous leaves are variegated - grey-green with white stripes. The Allium has thinner, long, slender, green leaves, which die away when it flowers. Both bloom in early summer, giving a good colour combination and interesting contrast in flower shape.

The Iris's stems carry up to six, large, scented, lavender-blue flowers which have distinct silver, papery bracts at their base. The Allium flowerheads are about the same size (4ins across) but are perfect globes of numerous purplish-pink, star-like flowers - a hemisphere of tiny explosions.

John the Gardener