Time to plant: Spring or autumn.
Metallic clumps of astelia, an architectural plant that originates from Australia, make a strong statement rising from tapered containers. The silvery, strap-shaped leaves sparkle in sunshine and contrast vividly with the dark tones of the pot.
A single container planted with an astelia would make an eye-catching feature, but here they become a design tool. A number of plants grown in identical containers can be used to add movement to a space, leading the eye from one part of the garden to another.
For instance, they could be placed up a flight of steps, along a low wall or down a path. Choose containers that complement the plants you are planning to grow and are large enough to accommodate their rootballs.
A series of containers like this can also be placed in a row to create a visual and physical barrier alongside a patio, or to separate off one part of the garden.
Cover the surface of the compost with a mulch of decorative gravel to suppress weeds and reduce moisture loss. Raise containers on pot feet over winter to help water drain away.