What are perennials?
The term ‘perennials’ is used loosely by gardeners to indicate those plants which grow in beds and borders, which are not trees, shrubs or bulbs. They are the ‘summer colour’, the ‘border flowers’ and make up a ‘flower garden’.
The two terms commonly used by gardeners are:
- Perennials This is used for all non-woody perennial plants, including herbaceous perennials. It includes those which are evergreen or semi-evergreen such as Bergenia (elephant’s ears), epimedium, hellebore, Stipa gigantea (an ornamental grass).
- Herbaceous perennials differ in that all the stems die back in late autumn and early winter. The roots then survive below ground during winter, shooting again in spring. Well known examples include delphinium, geranium, miscanthus (an ornamental grass) and sedum.
To be more botanically precise, the following applies:
- Perennials plants usually live for many years (those described as ‘short-lived’ perennials may only live for a few years) and vary substantially in shape, size and habit
- The foliage may be evergreen or die back in winter
- It should be noted that the term perennials is often used by gardeners to exclude woody plants (trees, shrubs and sub-shrubs). However, botanically, ‘perennial’ just means plants that live for many years, so can be applied to woody plants too