What is variegation?
Even if you’re new to plants and the growing hobby, you’ve most likely stumbled upon the word variegated . What are these popular plants, and what makes them differ from their counterparts?
Variegated plants are plants that have leaves with pale sections that are not fully green. This is due to a lack of green pigments– chloroplasts. These are the parts in each plant cell that enable photosynthesis, and also give the leaves their green color. A variegated leaf is not totally green and will have sections or patterns of white, light green or pink coloring. To some, this is highly attractive while others don’t like it as much - it’s a personal taste.
The patterning can be rather dramatic and make a bold impression, so you might not think that they fit in all environments aesthetically, but can be stunning in the right setting. You might find variegation in large white sections, or just in a fine speckling or dotted pattern. Others can even look like a gradient from green to pure white on the leaf. It’s all up to the variety of the plant.
Where do they come from?
Variegated plants are often very rare and spontaneous in origin. They’re spontaneous mutations found by people, either in their own plant collections or in the wild at some point. It can be very hard to intentionally create new varieties from several types of variegated plants, while some can rather easily be intentionally bred and grown from seeds.
Colors
There are some different colors variegated plants can present on their leaves. This depends on which plant it is and the type of variegation. In the leaf, there are several layers of cells, and in some cases there’s only one layer that’s not producing chlorophyll. Apart from chlorophyll many leaves also make other pigments, and these can also be affected by variegation to stand out more.
White / cream / yellow patches usually appear if there’s no chlorophyll present at all in that section. Cream and yellow then appear if the leaf has some yellow base pigments. Pure white patches are the product of lacking both chlorophyll and yellow pigments. Some examples are Monstera deliciosa ‘Variegata’ or Monstera adansonii ‘Aurea’
Green shades are the result of either one or several layers of cells in the leaf lacking chlorophyll but there’s still at least one layer that is green. The result is often a camouflage-like pattern of dark and paler green spots. Some examples are the pothos Epipremnum aureum ‘Global Green’ and Dieffenbachia ‘Reflector’
Pink / Orange sections are the result of a naturally dark or reddish leaf that lacks chlorophyll. Without the green pigments there’s only the pink or orange pigments left in the leaf. Some examples are Philodendron ‘Prince of Orange’ and Caladium ‘Strawberry Star’
Collecting them
Collecting plants is a hobby that is increasing in popularity. Some may collect rare species within a certain group of plants, while others primarily collect variegated cultivars. Among many species, the variegated forms are often rarer than their fully green counterparts which also adds to the interest in having one.
But why are some variegated plants so expensive? It has to do with a sudden high demand for specific cultivars that are not yet established among commercial growers, and the fact that they must be propagated by cuttings. The green regular forms are often already more established in culture, and they can also be tissue cultured in greater numbers faster if needed, which often isn’t possible for many of the variegated plants.
Special care
The care of your plant should first and foremost be according to the species you’ve got. There are however some things to keep in mind to keep variegated plants happy.
Sensitive to sunlight
Since these plants lack pigment in sections of the leaves, they’re more prone to getting burnt by direct sunlight. Even some varieties of plants that can usually handle full sun will be more vulnerable in their variegated form. These include plants such as the rubber tree Ficus elastica ‘Tineke’ and candelabra spurge Euphorbia lactea ‘White Ghost’ which will have to be very slowly acclimated to bright light to avoid burning. If you’re unlucky the white parts will dry and turn brown from the sunlight.
Pruning away pure green and white shoots
Some variegated plants have “unstable” variegation. This means that the proportions of green and white of the leaves can vary some as the plant grows. If suddenly your plant puts out several totally green or fully white leaves in the newer growth, this means that it has either reverted back to green or gone fully albino. Both of these cases should be treated in time if you want to keep a healthy and balanced variegated plant.
When a branch reverts back to fully green, it’s not harmful for the plant itself, but in order to keep it and the future growth of the plant variegated, you’ll have to remove the reverted growth. Prune away the branch to the point where it still produced variegated leaves. This makes it more likely to grow new variegated branches from the remaining growth points. If you have a plant that is easy to root, you now also have a green cutting to propagate as well. If left on the plant, you risk having the fully green branch take over as it will grow a little faster, and the plant might not promote growth in the variegated branches.
When a branch turns fully white without any signs of chlorophyll you also have to remove it. Continued growth will result in the plant spending energy and resources without the possibility to sustain itself in the future, and it will slowly grow weaker and weaker. Cut away this branch to the point where it’s still variegated. Unfortunately the removed branch won’t be able to sustain itself so trying to root it is unnecessary and will be doomed to fail if it totally lacks chlorophyll.
Different causes of variegation
Chimera - spontaneous mutations or sports
The chimera type of variegation is a type that is rather common in the houseplant hobby. It occurs when one or several cell layers in the growth points mutate and suddenly lack the ability to produce chloroplasts. This is one of the less stable forms and it can often revert to fully green again. This is totally spontaneous due to which cells dominate in the apical growth and is not determined by factors like how much light the plant gets or any other environmental conditions.
For the especially interested person, it might be interesting to know that there are three main types of chimeral variegation:
Periclinal chimeras - the most stable type where one or several cell layers in the apical meristem is totally variegated
Mericlinal chimeras - less stable where one or several cell layers are partially variegated and can therefore more easily revert to green
Sectorial chimeras - an unstable form that often reverts rather quickly in newer growth
A true chimera type of variegated plant won’t be possible to propagate through sowing seeds, nor will it be possible to clone it successfully through in vitro cell culture. The only reliable way to propagate them is through vegetative propagation - simply by taking cuttings.
Some examples of chimera type variegated plants are monstera, Monstera deliciosa ‘Variegata’, the arrowhead plant Syngonium podophyllum ‘Variegata’ and the pothos Epipremnum pinnatum ‘Variegata’ .
Pattern Variegation - genetic
There are also other types of variegated plants that are genetically variegated. It has nothing to do with mutations in separate cell layers, and is instead a genetic trait found in all cells of the plant. Because of this, this trait will therefore have a chance of being inherited in the offspring - you can sow seeds of the plant and the seedlings might turn out variegated. This type is possible to propagate through cell culture too. One example is the Monstera deliciosa ‘Thai Constellation’ that went from rare find to widely available in a short period of time. This was due to the possibility of tissue culturing a genetically variegated plant.
Virus
Some plant viruses can cause affected tissue to partially stop making green pigments. This can be seen in both the flowering maple, Callianthe × hybridum ‘Thompsonii’ and the Swedish ivy, Plectranthus verticillatus ‘Variegatus’. Both are rather stable forms of variegation and any virus in the plant can also be spread to other plants. It’s often spread by vectors like thrips and other pests that suck the sap on an affected plant, then spreading it to an unaffected one of the same species or genus.
Chemically induced
The least reliable type of variegation is the induced type. These are plants that are purposely subjected to chemicals in order to turn them variegated for a while. It often wears off after a while and you end up with a green or naturally colored plant in the end.
Some examples of induced variegation you can stumble upon are Philodendron ‘Pink Congo’ and the snake plant Dracaena ‘Star Canary’.
Propagation
Propagation of variegated plants is similar to the method used for regular green forms of the same plant. Most can’t, however, be propagated by seeds, but it also depends on what type of variegation it is. Seeds from a true chimera type will unfortunately only result in green seedlings.
If the plant type you have is easy to root as stem cuttings, use this method. Since the leaves of the cutting aren’t as green as usual, it will be especially important to give your cuttings a grow light during the darker months of the year to promote healthy growth.
