GREAT OUTDOORS Add interest to your garden skyline with some spiky plants
MOST garden shrubs and flowers have a rounded outline, summer or winter, and that brings a certain sameness of shape to the garden. By contrast, spiky shapes are lively, and counterbalance an excess of globes. Just a few spiky plants can make a big difference. In fact, too many spikes can make a garden space seem unsettled and uncomfortable.
There is a good choice of spike-making plants, all of them evergreen so they can work their magic in winter and summer. If anything, they are more effective in winter, when they provide greenery as well as shape.
Phormium or New Zealand flax is among the best-known of these spiky plants. The new sword-shaped leaves stand upright and later they arch over. The leaves can be more than one-metre long and more than 5cm broad.
Being not fully hardy, many phormium plants were killed during the cold winter of 2010, and people vowed never to plant them again, but memories are short, and new plants have been planted. This plant has a range of coloured foliage: yellow, brown, pink and purple-black. It has tall flower spikes in summer.
Similar in structure to phormium is astelia, also from New Zealand, with broad sword-shaped, pointed leaves, covered with persistent white hairs that give a long-lasting bright silvery look. It grows slowly to make a broad clump and, like phormium, appears much the same year-round. It has brown flower spikes carried down amid the foliage, and not of any significance.
Yucca is a noted spiky plant, even more so than phormium, as the broad spikes come to a point. The rosette of spiky leaves produces a tall spire of beautiful, nodding, waxen, white flowers in late summer.
Related to yucca, beschorneria has broad green leaves year-round and produces a spectacular three-metre tall spike of red and yellow flowers, and is for gardens within a couple of kilometres of the coast. Agave is even more tender but can be grown in a pot to move out for summer and it would nicely decorate a greenhouse or conservatory in winter. All three originate in Central America.
Red-hot poker is a good spiky plant, popular in gardens. Some small species lose their grassy foliage in winter and contribute little towards a spiky effect, but there are large species that are evergreen with upright spikes, relatively narrow. The plants produce tall flower stems with a cluster of tubular red and yellow flowers at the top.
Also from South Africa, dierama has narrow arching leaves and looks grassy but it has a spiky touch too, as does watsonia, the latter not being as hardy in cold areas.
There are others such as libertia and sisyrinchium, but any spiky outline does the job.