An amazing Australian, evergreen, woody perennial. It has a great pack of grass-like leaves at ground level which radiate out from the centre of a tall, thin, vertical trunk. In its native south-western Australia it can reach 2.7m high but don't expect that over here. Initially slow growing, it blooms irregularly in spring producing white flowers which attract plenty of bees. Needs excellent drainage and hot, sunny conditions. Withstands droughts.

Also known variously as 'Black Dragon', 'Ebony Knight', or 'Arabicus', this is an extraordinary looking plant with purple-green leaves that turn jet black when grown in full sun and very well-drained soil. As it is so dwarf, it is easily lost in a border and looks best grown on a rock garden or raised bed. Left undisturbed it slowly forms fair-sized colonies and looks good interplanted with small wandering perennials, such as Geranium farreri with its contrasting, lacy foliage and fragile pink flowers. It also makes a good foil for dwarf rock garden bulbs in spring. The Royal Horticultural Society has given it its prestigious Award of Garden Merit (AGM).

The pretty blue flowers and low, clump-forming habit of the flax lily, make it an ideal ground cover. Its spiky, grassy foliage is tinged blue, giving it year-round interest even when not in flower. Flax lilies are very forgiving plants and will tolerate a wide range of conditions, including direct sunlight, drought, waterlogged soil and even deep shade. The plant benefits from a thick mulch and occasional fertiliser to keep it looking healthy. Remove the older, outer leaves before flowering in early spring to keep the plants looking tidy.

This striking perennial from New Zealand holds the Royal Horticultural Society's prestigious Award of Garden Merit (AGM), which is for plants of outstanding excellence. It makes a tall clump of spiky, upright, dark green leaves which are blue-green underneath. In summer, stiff stems of dull red, tubular flowers are produced. Grow in a sunny spot in moist but well-drained soil. Plants are half hardy so in colder areas they will need to be overwintered in a frost-free place. Good in a warm, seaside location.

This is tender plant from South Africa which can be grown in the greenhouse. It has truly exotic and unforgettable blooms in rich, iridescent orange and midnight blue. These flowers conjure up the image of its common name, bird of paradise. The leaves are large and oblong to lance-shaped, similar to the leaves of a banana plant. Plants can be brought out onto the patio in summer in very warm, sheltered areas.The Royal Horticultural Society has given it its prestigious Award of Garden Merit (AGM).