Modern landscape is often described as pretty as a picture with pleasing scenery, where a sense of liveliness, contrast, movement and depth, is the goal. Variegated plants are invaluable in achieving that goal. They can enliven shade or a dark background or corner and create a feeling of depth and movement. By virtue of contrast, variegated plants help to define adjacent plain-leaved plant more sharply. Total absence of plastid pigments causes a sector of a leaf or stem to have white patches. This condition is termed variegation. Variegation is produced when there is a cell mutation (cytological chimera), and all cells produced from that mutant mother cell lack the pigments, either because plastids are not present or the plastid cannot complete the manufacture of the pigment apparatus. The zones where chloroplasts are not present are zones where no photosynthesis will occur, hence a variegated leaf has a lowered potential to fix carbon dioxide into sugars, and as a consequence, a variegated plant also tends to grow more slowly which suits best for growing them indoor.
Types of variegation:
Variegated leaves occur rarely in nature but are extremely common among indoor and outdoor ornamentals. Species with variegated individuals are sometimes found in the understory of tropical rain forest, and this habitat is the source of a number of variegated house plants. Some variegated ornamentals have only a fringe of white around the leaf (Pittosporum), sometimes irregular dots (Bromeliads and Begonia) and spots (Diffenbachia), sometimes broad panel of white patch (bromeliads), end even a occasional leaf that total achlorophyllous. Some very colourful variegated leaves can produce vascular pigments, such as anthocyanine (Acalypha).
The types of variegation are as follows
Marginal: Some of the variegated plants are with contrasting edging on leaves, a yellow or white margin around a central green or grey area. Example Eleagnus pungens
Cantered: The variegation occurs through central midrib of leaf, example-Spider plant (Chlorophytum comosum).
Streaked: Nongreen strips normally found longitudinal or parallel, to leaf midrib or edges. Example- Cannas, Heliconia indica.
Blotched: L eaves bearing variegation in a patch on it. Example- Monstera, Pothos
Speckled: Variegation causes the yellow or white spot over leaves. Example- Dracaena (Dracaena surculosa).
Veined: Leaves have white or no green veins, causing leaf, to appear variegated. Example Fittonia albivenis.
Patterned: Reflects white or nongreen colour in a unique pattern all over the foliage example Tapioca (Manihot esculenta).
Variable: Leaves with mottled, splotchy variegation example; Ficus microcarpa
Care of Variegated Plants
Indoor areas have more challenging conditions for excellent growth, such as minimum light and rather inadequate ventilation. Inside, night temperatures are warmer. There are drafts and the atmosphere is drier. Therefore, selection of appropriate indoor variegated plant is the most important factor what should come in the mind. The major considerations should be directed toward the plant's foliage and how the plants grow. The leaves may be selected for their colour or form, or both. Generally these plants are of slow growing habit which is an advantage. They will perform well over a longer period of time without a great deal of pruning or training.
Light: Plants requiring more light usually have variegated foliage. This is because they have less chlorophyll and require more light to achieve the same photosynthesis as a plant with green foliage. If light is insufficient, colour variegation may be lost. An incandescent light bulb gives off limited colours is not acceptable as an indoor lighting source for most of plants. To grow plants under artificial fluorescent light, most indoor gardeners combine a cool and warm tube in a fixture to provide light of good quality for many interior plants. Duration refers to the length of light exposure. A daily exposure to light, preferably 8 to 16 hours, is needed for plant processes.
Temperature: The best temperature range for the most interior would be in between 18-25 °C. Chilling injury occurs below 10°C for most of the tropical plant. Plant kept in south or south-west receives warmth because of sunlight. Keeping plants near hot drafts from opening doors or air conditioning vents should be avoided.
Humidity: An average home may have 35% to 60 % relative humidity, this may drop 20% in winter in heated homes. Low humidity may cause brown scorched leaf. This can be improved by grouping plant and using room or furnace humidifier.
Potting mixture: One should be sure about the particle size, plant root aeration and the drainage capacity of the potting mixture. Most variegated plant do well in a mix containing two part potting soil, one part moisten peat, and one part course sand. Native soil can be used if it is properly pasteurized.
Pruning and dusting: The browned tips of leaves or leaves that are yellowing should be removed. These can occur even on healthy plants, primarily in the winter. Plants with thin, sharp tips such as Dracaena, Spider Plant, and Aspidistra suffer most. In the winter, dust from the heating system can coat the leaves, clogging the pores (stomata). In the summer, when windows are open, there is even more dust in the air to collect on plant leaves. Dust can be removed in several ways. A damp, soft cloth or sponge is good for plants with large leaves. Ordinary tissue will also do, but be gentle so as not to bruise the leaves.
Watering: Plants should be watered when needed. The leading cause of most house plants deaths is over-watering. Checking the plant weekly the finger test is the best way by placing index finger deep into the potting soil. If the medium is moistened no watering is recommended. But if the mix is dry, completely saturate the potting soil is necessary.
Insect and pest control: Occasionally, house plants may suffer insect problems. Controlling insects such as aphids, mealybugs or spidermites may seem to be a never ending battle, but the use of a systemic insecticide containing 'di-syston' granules as a preventative measure will help.
Common variegated plants for indoors air filtration
Plants filter Xylene and Toulene
Homalomena wallisii , Ophiopogon jaburan, Chlorophytum comosum, Dieffenbachia spps., Sansevieria trifasciata, Dracaena deremensis, D. godseffiana , D. sanderiana, Cordyline terminalis
Plants filter Benzene
Aglonema psedobacterium, Alocasia macrorrhiza, Spathiphyllum wallisii, Dracaena deremensis, D. godseffiana, D. sanderiana
Plants filter Formaldehyde
Euonymous japonica, Philodendron domesticum, Philodendron imbe, Tradescantia fluminensis, Scindapsus aureus
Plants filter Trichloroethylene
Spathiphyllum wallisii, Tradescantia fluminensis
Variegated plants have been long-valued by gardeners, as the usually lighter-coloured variegation can 'lift' what would otherwise be blocked by solid green foliage. Variegated plants are becoming still more and more popular all the time, particularly with the increasing practice of tissue culture and with increasing need to collect unusual things. Many variegated plants that were once rare and costly are now becoming common, which of course makes them less 'collectible'. The truth is variegated plants quite striking and excellent landscape subjects or specimens for indoors, and now it is proved that they are suitable to improve the indoor air quality as well.
About Author / Additional Info:
Scientist, working on flower crops at Directorate of floricultural Research.
My email id: email@example.com for further information.