Variegated plants enhance gardens and indoor spaces adding a wealth of hues and tones to the vibrant greens of other plants. Plants with variegated foliage can substitute the temporary burst of colour provided by flowers. There is a huge variety to choose from, spanning the spectrum of plant species, and including foliage plants and succulents. In fact there is a plant to suit all needs.
Variegation, or the appearance of multiple zones of colour, can occur in leaves, stems and even flowers, although the most common is in foliage. Plants with variegated leaves can occur in a variety of shades, colours, and patterns. Patterns range from spots, patches, stripes or borders and occur in colours such as pinks, reds, whites, and greens. The most common variegation is bicolour, where the green foliage is patterned with a lighter colour. Tricolour variegated plants have three different colours or shades and quadricolour have four. Among all of these types, some plants can have well demarcated variegated sections, whereas others may have a more subtle appearance,
The pigment responsible for the green colour in plants is chlorophyll and a lack of production of this pigment will result in variegation. Other pigments that can be found in plants include carotenoids which are responsible for yellow and orange hues, and anthocyanins which are red and purple in colour.
Variegation can occur in the following ways:
Pattern-Gene or Natural Variegation
This type of variegation occurs in the same pattern across the entire plant. It is a result of the normal gene expression of the plant and any propagated plants will be true to form and can be produced through cuttings and seeds. Plants in this category include rattlesnake calathea and fishbone prayer plant.
Chimeral Variegation
This is the most common type of variegation. It is caused by a gene mutation that manifests as areas of variegation which occur at random and have no fixed pattern. Some parts of the plant tissue can produce chlorophyll while others cannot. As a result, some leaves have more discolouration, some have less, and some leaves are entirely discoloured. It is more difficult to propagate chimera as this can only be done through stem cuttings and these may not exhibit the same physical appearance as the mother plant. This can occur in plants like the variegated monstera deliciosa.
Blister/Reflective Variegation
When tiny air pockets form between the pigmented lower and unpigmented upper layers in the leaves of a plant, blister variegation occurs. This gives a silvery appearance to the plant because the light is reflected off these air pockets. This type of variegation can be random across a leaf producing silvery spots, like in the satin pothos. It can also occur more uniformly across the veins of leaves, as often found in anthuriums, alocasias, and philodendrons.
Viral Variegation
Some variegated leaves are produced by viruses. There are a number of viruses responsible for viral variegation and their patterns are determined by the virus they are infected with. For example, the mosaic virus produces a mosaic-like effect on the surface of a leaf, while the hosta virus X causes a mottled appearance in the leaves of hosta plants. These can be reproduced, however often gardeners do not cultivate affected plants as these viruses can spread to other plants and cause serious disease.
Care and maintenance of variegated plants
Variegated plants can require more care and attention to maintain their variegation. While these plants need enough water to stay healthy and build chlorophyll, overwatering can encourage the overproduction of chlorophyll and therefore the loss of variegation. If a plant starts to develop green leaves, prune and remove these as they will grow faster than the variegated ones and increase the chances of the plant reverting to the non-variegated form.
Moving a plant to a better lit, sunnier position can help compensate for the lack of chlorophyll in variegated types. Placing these plants in shadier positions can cause the plant to produce more chlorophyll in response to low levels of light and lose their variegation.
Feeding variegated plants with a low nitrogen fertilizer reduces the chances of the plant reverting to its non variegated form as nitrogen can increase the production of chlorophyll.