Shrubs can be defined as woody plants of relatively low height, having several stems arising from the base and lacking a single trunk. Common shrubs are plants like plumbago, abelia, or tecomaria. Many shrubs are ideal for hedging (see hedging page) if they are pruned carefully into shape. Be careful not to prune before the shrub flowers, or you will lose most of the benefit of growing a flowering shrub.
The shrubs and perennials have been listed together in the attached sheet, as most can be used interchangeably in the garden.
A perennial can be defined as a plant that recurs again and again. Perennials often die back in winter, and through their underground root system (or bulbs) they will re-generate in spring. Some perennials will remain leafy throughout the year. Others will die back above ground and send up fresh growth in the new season (such as crocrosmia).
When planting shrubs, a number of issues need to be considered:
Height: A common mistake, made by new gardeners, is to plant tall shrubs at the front of the flower bed, thereby obscuring all of the plants unfortunate enough to be planted behind. Knowing the ultimate height of the plant is an important consideration in planning a flower bed. The list of shrubs attached gives the expected height of each plant in a Johannesburg climate. Plants growing in more temperate climates would be expected to grow taller and spread more.
Sun/Shade: Plants that need full sun will not reach their full potential if planted in the shade. Some plants may simply refuse to perform at all, unless moved to a better spot in the garden. Shade loving plants will wilt if planted in full sun and will often die back. Sun loving shrubs will seldom flower in shade.
Hardy or Frost Tender: Planting tree ferns or Cuphea in areas that commonly experience frost or temperatures below zero will not produce satisfactory results. Some plants are sensitive only in their early years, and if protected, it will often perform very well in adverse climates. Duranta sheenas gold is an example of a plant, which is very frost sensitive as a young plant. After two or three winters, if it is still alive, it will often grow into a beautiful shrub, and continue to perform even in cold, frosty winters.