Zanthoxylum piperitum Black Magic

The Zanthoxylum piperitum 'Black Magic' is a rare form of the Sichuan Pepper, highly sought after by collectors: its delicate fern-like leaves are remarkably coloured in shiny chocolate-purple. Like its Asian ancestors, sometimes called Clavalier, this bush has remarkably aromatic foliage, but unlike its ancestors, it does not produce aromatic fruits. The combination of small flowers and foliage taking on shades of golden purple in autumn is superb in this Chinese pepper tree that will be decorative 9 months out of 12. Fantastic as a stand-alone, it is also ideal as a free hedge, and its young, thorny branches are lovely in a defensive hedge.

Native to the Sichuan province, located in southwest China, the Zanthoxylum piperitum is widely spread from Japan to Vietnam. It is part of the same family as citrus trees, the Rutaceae family, with which it shares a highly aromatic foliage. Zanthoxylum is a group of plants that look very similar, making them tricky to tell apart. People usually use things like how many leaves they have or what the flowers and thorns look like to figure out which one is which. This large bush loses its foliage in winter, occasionally withstands -18°C (1°F) and develops in well-draining and sufficiently deep soil. Late frosts can, however, harm flowering and burn its young shoots. The Chinese pepper tree is extremely tenacious and can grow in any condition except for dense shade.

Growing quickly in moist and fertile soil, this 'Black Magic' pepper tree measures an average of 3m (10ft) in height with a similar spread at maturity. Its habit is elegant, naturally bushy and spreading, supported by flexible branches. The trunk and young branches are adorned with flat thorns that broaden significantly at the base over the years while their tips become blunt. They eventually form curious growths that resemble large warts. The branches, of a brown-purple colour, bear leaves arranged alternately, 7 to 15 cm (3 to 6in) long, divided into 11 to 23 small ovate and glossy leaflets, toothed at the edges, producing essential oils and small barbs. When crushed, they emit a scent that is spicy, woody, lemony, and slightly peppery but mild. Their colour successively changes from purple-violet to dark green, and then they take on yellow, orange, and pink-purple hues in autumn before falling. The flowering already appears on 3 or 4-year-old plants (since sowing). It occurs in May-June, more or less early depending on the climate, on one-year-old branches. It consists of small clusters or cymes about 3 to 5 cm (1 to 2in) in diameter, composed of small cup-shaped flowers in a yellow-green colour. This selection only has male flowers, so the plant cannot produce fruit.

This beautiful bush, with its fascinating foliage and unusual bark, deserves a special place. It can grow into a beautiful tree if planted in isolation. You can trim the lower branches up to 1 metre (3 feet) from the ground to reveal its tall, bare trunk. Alternatively, it can be planted in an untrimmed hedge alongside other plants such as dogwoods, rowans, viburnums, Osage oranges, ornamental apple and cherry trees, or honey locusts. 

The Zanthoxylum has thorny young branches, making it an excellent choice for a defensive hedge. You can combine it with Poncirus trifoliata, Rosa moyesii, Japanese quince Cido, seabuckthorn, and more to create a defensive hedge.