Wall shrubs, such as firethorn, are easy to grow and provide a rich tapestry of evergreen foliage, spring flowers, and vibrant autumn berries that add texture and color to the garden. On a boundary, their sharp thorns also deter intruders, and the fruits provide a feast for hungry birds.
When to Start: Autumn
At Their Best: All year round
Time to Complete: 2 hours
Plant your firethorn about 20 in (50 cm) from the wall or fence, and dig a bucketful of organic matter and some general-purpose fertilizer into the soil within the planting area. Do not add extra organic matter to the planting hole.
Fix horizontal wires across the wall or fence. Dig a planting hole twice the width and as deep as the plant pot. Place the firethorn in the hole and lay a stake across the top to check that the plant will be at the same depth as it is in its pot once planted. Remove from its pot, and plant. Backfill with excavated soil and firm in with the ball of your foot. Remove stems from the supporting canes supplied with the plant, and tie to the wires with twine.
With clean, sharp clippers, prune wayward stems that are growing away from the wall or fence. Cut them back to the main stem or a bud close to a stem that is growing along the fence. Shorten other side shoots to encourage bushier growth.
Water the plant well, and apply a thick mulch of well-rotted organic matter, keeping it clear of the stems. Water regularly for a year or two, until the plant is well established. Only water during prolonged dry spells thereafter.
In spring, when flower buds appear, cut back outward-growing stems, or those growing towards the fence, and shorten others to keep the plant compact, making sure that you retain as many buds as possible. Wear heavy-duty gardening gloves to protect yourself from the thorns. In late summer, cut the stems back to within a few buds of the berries so that the fruits are more visible.
For flower rather than berries, try one of these beautiful wall shrubs. Each has its individual charms: both the Californian lilac and the silk-tassel bush are evergreen, while the flowering quince and flannel bush have bright, colorful blooms.
Flowering quince, Chaenomeles x superba; H5 ft (1.5 m) s6 ft (1.8 m)
Californian lilac, Ceanothus ‘Concha’; E5–10 ft (1.5–3 m)
Silk-tassel bush, Garrya elliptica; E12 ft (4 m)
Flannel bush, Fremontodendron californicum; H20 ft (6 m) s12 ft (4 m)
Heralding spring, the bare branches of the flowering quince, Chaenomeles (image 1), are laced with bright pink or red flowers, and are followed by the blue pompoms of Californian lilacs, Ceanothus (image 2), which open at the end of the season. The flannel bush, Fremontodendron (image 3), has large waxy yellow flowers that appear from late spring to early autumn, and to close the year, the silk-tassel bush, Garrya (image 4), displays its long cream catkins while the rest of the garden sleeps.
Plant the Californian lilac and flannel bush in a sunny spot. The silk-tassel bush and quince will grow well in partial shade or full sun. None of these plants, apart from the quince, tolerate hard frosts so select a sheltered area, and follow the same planting method as for firethorn. You can train the plants onto a trellis instead of wires, if you prefer, but make sure that it is fixed securely to the wall or fence.
Although these shrubs tolerate very dry conditions, water them frequently for the first year until they are established. Trim back the quince and lilac annually after flowering in early summer. Prune the silk-tassel and flannel bushes in mid-spring. Prune out wayward stems that are growing away from their supports, and trim other stems to create a neat framework. Tie in long stems to the wires or trellis. The plants will also benefit from an application of granular shrub fertilizer in early spring.
Excerpted from How to Grow Practically Everything
© Dorling Kindersley Limited 2010