A naturally occurring

Genes are small sections of DNA that code for particular traits. During sexual reproduction, genes of both parents are mixed to create a genetically different offspring. Plants grown from seed may not be 'true to type' and look like their parents, but genetic variation can be beneficial, creating new, interesting characteristics and sometimes improving resilience to environmental conditions or disease. On the other hand, plants grown from cuttings are genetically identical to their parents.

Perennials are plants that live for multiple years. They come in all shapes and sizes and fill our gardens with colourful flowers and ornamental foliage. Many are hardy and can survive outdoors all year round, while less hardy types need protection over winter. The term herbaceous perennial is used to describe long-lived plants without a permanent woody structure (they die back to ground level each autumn), distinguishing them from trees, shrubs and sub-shrubs.

perennial

Generally, you may only notice one or two mutations on a plant, for example, there might be just one different coloured flower on a plant. Usually the plant will revert back to its original form the following year.

Most mutations are random and are a result of a change within the cells of the plant, but mutations can sometimes be triggered by cold weather, temperature fluctuations or insect damage.

Sometimes the mutation is unnoticeable because the characteristics are not passed on from the cell where they occurred, but if the mutation occurs at the growing point, entire shoots can be affected as that cell multiplies and gives rise to whole cell lines.

The term chimera is used when genetically distinct tissues co-exist within the same plant or parts of a plant. For instance, some plants, such as chrysanthemums, roses and dahlias are prone to producing chimeral flowers, where the flowers have sectors of different colours, and chimeras are the usual basis for variegated plants.

Generally, genetic mutations are not a problem, and can be pruned out if undesirable; however, many sports will die out or revert back to their original form of their own accord.

Some sports are stable and may be of interest to nurseries who actively seek out new plants. Members of the RHS can contact RHS Gardening Advice to request a list of nurseries that advertise for new plants.