Life is a glorious summer garden filled with bright colour and interesting shapes. Joan Wright tells you how to make your summer garden more attractive with colourful flowers and plants with contrasting form.

Where do you need colour?

If there are places in the garden that are dull and uninteresting, places where you do not linger, this is where colour can be effective:

Yellow: Shrubs with yellow flowers that are wind resistant and that give really good value throughout summer include Euryops pectinatus with yellow daisy-like flowers and grey foliage, Lantana montevidensis 'Sundancer', good on banks, clipped into mounds, or encouraged to spill over low walls, and thryallis (Galphimia glauca), a small shrub covered in clusters of yellow flowers. pots of brightly coloured, heat-resistant annuals, such as the cockscomb celosia, marigold, salvia and zinnia.

Blue: cools down hot colours. Agapanthus with flowers in shades of blue, flower best in sun or a lightly shaded position. Agapanthus 'Blue Velvet' is tall growing with navy-blue flower heads, and 'Silver Star' has green leaves edged cream and pale blue flowers. Shrubs with blue and lavender-blue flowers include Evolvulus glomeratus 'Blue Daze', felicia, Otocanthus caeruleus 'Blue Boy', plumbago and Plectranthus 'Mona Lavender'.

Pink: is pretty with silver-grey artemisia, lavenders and blue-grey Festuca glauca, and striking with lime-green foliage. Day lilies in shades of pink could be grown in front of a group of clipped Duranta 'Sheena's Gold'. Tall pink lavatera is an annual for the back of a sunny border, while Impatiens New Guinea Celebrette 'Hot Pink' will brighten a shady corner.

Where do you need contrast?

Even the smallest garden can be made to look more interesting when different plant forms and textures are included in the design. A path leading to the front door can become more attractive by planting a grove of the indigenous lavender tree, Heteropyxis natalensis with a slender and upright growth habit, flaking bark and glossy, lavender-scented leaves, with an evergreen ground cover of Australian violet (Viola hederacea).

Groups of the grass Aristida junciformis, Dietes grandiflora and bulbine, set among weathered rock, work well in hot, dry spots. Miniature agapanthus, bulbine, crassula, tulbaghia, asparagus fern and hen-and-chickens (Chlorophytum comosum) can be grown as ground covers, or in great sweeps along a driveway.

Use giant clay or glazed pots in the garden as focal points and give them a carpet of dwarf maroon-leafed Phormium tenax 'Rubra', Carex 'Evergold' or day lily 'Stella Supreme'. Plant a row of containers with one type of plant with striking form, such as phormiums or Cape restios. The dwarf Aloe 'Hedgehog' is a favourite for clay pots.

Shrubs are of great importance in a garden as they anchor and add stability to the design. Indigenous Croton pseudopulchellus, with layered branches and shiny green leaves with the underside of the leaves a silvery-white with orange speckles, and Indigofera jacunda with slightly weeping branches and sprays of pink flowers, are a pleasing contrast to plants with bold foliage.

Form is just as important in borders, where spire-like flowers, such as snapdragons, will balance rounded shapes of daisies, and trumpet flowers of alstroemerias and day lilies.

Tips

• Water before noon to allow plants to dry out before nightfall.

• A lack of humidity can cause the tips of palm leaves to turn brown, and regular watering is necessary as their root system lies close to the surface.

• Use a high nitrogen fertiliser for ferns and palms.

• Use a general fertiliser for flowering plants.

• Watch for lily borers that burrow into agapanthus