Variegation Explained

Any plant lovers who have spent time on the internet recently will have come across swathes of variegated plants. Whether it’s the incredibly popular variegated Monstera, the collectable cultivars of the Epipremnum aureum species, or even outdoor ornamental foliage plants, variegation is taking centre stage this year.

Read on for variegation explained!

We may be able to recognise a variegated plant when we see it – but what actually causes this colour change in the first place?

The answer, as you may have guessed, is not a simple one. Firstly, there are different types of variegation with different causes. Some are naturally occurring within the plant cells, and others are caused by external factors, such as disease. In many instances the disease could be a virus which doesn’t affect the plant in any way other than the variegation.

Many ornamental plants with colour differences have a uniform variegation repeated on each leaf that looks very similar. This variegation is encoded into the genes of the plant and becomes a characteristic of that species.

chimeral variegation

The most sought-after variegation type, often present in popular houseplants, is chimeral variegation. This is the type present in the famous variegated Monstera and other plants where the leaves seem to lack pigment in certain areas. Chimeral variegation is caused by a genetic mutation in the cells of the plant that causes two separate kinds of tissue to develop side by side. This mutation makes the plant unable to synthesise chlorophyl – the part of the plant that make leaves green – turning them a lighter colour such as cream or even stark white. This mutation occurs randomly, which explains why newly variegated plants are so rare and sought after.

After generations of successful propagation, one specimen may develop a mutation that causes the variegation in the foliage. This specimen then needs to be propagated by cutting or tissue culture to test the stability of the variegation. After several attempts, the variegation may fade out altogether. However, those that are found to be stable are continuously propagated and sold on the market as variegated species, maintaining their interesting colour generation after generation.

Variegation can also occur when air is trapped under the first cell layer of the leaf, making the chlorophyl underneath invisible. This top layer reflects the light and makes those areas appear white or silver, seen in the popular houseplant Begonia maculata.

When it comes to chimeral variegation, the patterns are not set in stone. The plants have the ability to revert to their original green colour if conditions are not favourable – specifically lighting conditions.

The importance of light

Since the leaves lack chlorophyl when compared to non-variegated species, photosynthesis is generally slower. With enough sunlight, the plant will continue to grow happily, albeit slower than its related cousins. However, if the light is not sufficient to keep the plant alive with the little chlorophyl it has, it begins to produce more to make up for the deficit. This chlorophyl seeps into the variegated areas, turning them green again in an attempt to produce enough food to survive.

The key to maintaining variegation in your plants is therefore to give them the right amount of sunlight. This will vary depending on the plant, so make sure you understand their needs before you decide on their final home.

READ MORE: Everblooming Begonias