Ever wonder what causes variegation in your houseplants, why variegation changes or reverts, or why some variegated plants are insanely rare and expensive?
In general, variegation refers to foliage with multiple colours. Let’s go over the five different reasons that variegation emerges in foliage.
Five reasons for variegation in houseplants
1. Pattern-Gene/Natural Variegation
In the words of Lady Gaga, “Oh, there ain’t no other way, baby I was born this way”, natural variegation is literally in a plant’s DNA. These sorts of plants’ natural patterning is inheritable. Cuttings and seeds from these plants will have the same variegation as the parent, and this type of variegation is also stable — it won’t have random variations from one leaf to the next.
Examples of pattern-gene variegation are: fishbone prayer plant (Ctenanthe burle-marxii), rattlesnake calathea (Calathea lancifolia) and variegated spider plant (Chlorophytum comosum ‘vittatum’)
If the patterning is in the plant’s genes, it suggests an evolutionary purpose. Natural variegation can be a huge benefit to the plant, helping protect it from predators or to procreate. In the world of plants, predators are actually herbivores.
Scientists suspect variegation may help plants camouflage or appear undesirable to eat (as though they are sickly, poisonous, or have eggs laid on them). Will you look at your polka-dot plant differently now? Sorry…
The natural variegation we see in many indoor plants today is the result of breeding. Natural patterning is accentuated and manipulated by growers, through selection and hybrid creation. The results are ‘cultivars’, not native plants as they would appear in the wild. As a comparison, you could think of cultivars in the same way you might think of designer dog breeds — you won’t find packs of teacup poodles or puggles in the wild.
Quick tip — you can determine if a variegated plant is a cultivar from its name. If the name contains variegata (lowercase, italics) in the second part of its Latin name, this plant is a naturally occurring species. If you see ‘Variegata’ (uppercase V, single quotations) in the plant’s name, this indicates the plant is a cultivar.
2. Chimeral Variegation
Chimeral variegation is the most common type of variegation. A genetic mutation in the plant prevents the leaf from uniformly producing chlorophyll (the green pigment in leaves that converts sunlight into plant energy).
Visually, we see these mutated layers as white, yellow or light green patches on an otherwise green leaf. For instance, the Variegated Monstera deliciosa is an example of chimera variegation.
Plants with chimeral variegation may have a mix of speckled leaves, solid white leaves, and solid green leaves. It is also possible for a consistent chimeral variegation pattern across all leaves of a plant.
The Kalanchoe below is a perfect example of random, unstable chimera variegation. The plant started with white-tipped green leaves and is now producing new shoots with solid white leaves and solid green leaves.
Chimeral variegation differs from pattern-gene variegation because the mutation is random and unstable — the plant’s variegated foliage pattern may change or revert to solid green. Reproducing the variegation pattern through propagation is generally a roll of the dice. For this reason, some chimeral variegated cultivars are difficult (and expensive) to buy.
3. Blister/Reflective Variegation
Silvery or reflective spots on foliage come from air pockets (blisters) between the outer leaf membrane and the pigment layer (which contains green chlorophyll). The air pockets reflect light away from the plant, creating a sparkling silver look. You’ll find that these leaves appear variegated on top, but solid on their undersides.
Blister variegation patterns can appear consistent across an entire plant, as, for example, with watermelon peperomia, or random, like the blotches on a satin pothos. In both cases (random or consistent patterning) the type of variegation is part of the plant’s DNA. Correspondingly, it can be reliably passed along through propagation from cuttings or seeds.
Blister variegation is also responsible for the striking appearance of white veins on some Anthuriums, Alocasias and Philodendrons. Some specific examples are: Anthurium clarinervium, Alocasia frydek and Philodendron gloriosum.
The evolutionary purpose of blister variegation is to provide a bit of sunscreen for the plant cells. When plants receive too much sunlight it can cause photoinhibition (a reduction in the plant’s ability to photosynthesize).
4. Viral Variegation
Sometimes a virus is responsible for leaf variegation, as is the case with Mosaic virus. Sometimes this variegation is desirable and reproduced as cultivars. For instance, some hosta cultivars owe their variegation to a virus.
5. Chemical variegation
Plant manufacturers can use chemicals and dyes to temporarily change the colour expression of leaves. For example, manufacturers produced the Pink Congo Philodendron by feeding it a chemical that temporarily prevented the plant from creating chlorophyll, resulting in pink leaves. However, once the chemical wore off, after 6 to 12 months, the leaves reverted to their natural green.
The Pink Congo Philodendron created quite an uproar among houseplant enthusiasts, with good reason. These pricey plants with pretty pink colors were sold without disclosing the artificial and time-limited nature of the variegation.
Can I create variegation in a normal plant?
What causes variegation to revert?
When dealing with chimera variegation, sometimes there’s no rhyme or reason, producing solid green leaves is just part of the randomness. However, sometimes variegated plants revert because they aren’t getting enough sun.
If you think about it, leaves with variegation are less efficient at consuming sunlight because they have patches without energy-producing chlorophyll. Indeed, reverting to solid leaves helps a plant produce more energy with the same amount of sunlight available to it.
My plant is losing its variegation — what can I do?
As mentioned above, a plant will often benefit from solid leaves because they have more chlorophyll to convert sunlight into energy for the plant. However, to maintain variegation, try increasing your plant’s sun exposure and trim away solid-coloured leaves to discourage it from putting out more.
Why don’t my albino leaves last?
Albino leaves have no chlorophyll and, although we love them, they’re basically useless for the plant, and are actually a burden. While interesting to look at, these leaves don’t produce any energy for the plant, but need plant energy to keep on living. As such, plants aren’t particularly motivated to hold onto their albino leaves and consequently are more likely to drop those leaves as dead weight.