If your customers have found that as time passes, unique plants they once revered for their distinct color or shape have produced shoots that are ordinary green, there may be an odd reason behind it.
Variegated leaves can, over time, go through a process called reversion, and it occurs in many types of plants.
Reversion refers to the process when a cultivar known for a particular shape, color or other distinct characteristics “reverts” back to a different form found in the plant’s parentage, according to the Royal Horticulture Society (RHS).
The term, RHS says, is often used to describe a variegated shrub or tree that has produced non-variegated shoots.
It’s said that the loss of variegation in plants can be caused by a number of factors, such as lighting, seasonality and more, and unfortunately, once the loss of variegation has happened, it cannot be reversed.
While there is no reversal method known currently, you can still potentially save your customer’s variegated plants if the reversion process is caught early on.
When choosing this type of plant, the RHS says variegated plants are usually selected from a mutation, or sport, of a pure green plant. The part that is variegated is then propagated by cuttings, division or grafting to retain its features. The mutations within these plants, however, are not always stable, which leaves them prone to “reverting” back to shoots that are pure green.
The problem with variegated plants, many experts say, is that they tend to be less hearty and vigorous when compared to their all-green relatives. Some of the plants will produce growths that are albino, which cannot gather solar energy and will eventually die back. The plant is not likely to survive if all of the new growth becomes albino.
It’s also true that variegated plants tend to have smaller leaves, which make them less tolerant of shady areas, more likely to burn in sunnier spots and slower to grow.
Problem and symptoms
A common problem with variegated plants is the limited amount of chlorophyll in the leaves. When there’s less chlorophyll present, there’s less solar energy, which is a key component in photosynthesis.
Variegated plants are said to be less vigorous than green specimens, and experts say that the reversion tendency of variegated leaves is a protective adaptation that allows the plant to return to a form that is more successful.
The question now becomes, why does this reversion happen in the first place? A few suggestions have been that the plants do this as a survival technique, and others say it occurs because of another leaf cell mutation.
For variegated plants in shadier locations, the disadvantages grow, as they have lower levels of chlorophyll and are not exposed to adequate amounts of light, which can lead to variegated reversion.
Temperature changes can also play a part in variegated reversion, as some plants may revert to get a competitive advantage over the elements. When a plant’s leaves revert back to all green, the plant can increase its harvest of solar energy and get more energy to produce stronger, bigger growth. Similarly, plants that are waterlogged may also turn back, and their shoots will often come out green.
The RHS says that virus infections can also cause a form of variegation, and the organization also notes that very few variegated plants can be raised from seeds, as reversion usually is a growth disorder, not a genetic one.
It’s fairly easy to notice shoots that have reverted, as they will appear as pure green shoots that will emerge from branches of an already variegated plant.
These shoots will contain more chlorophyll than variegated plants and they are more vigorous and can take over the plant eventually. Mainly, RHS says this is a problem with variegated shrubs and trees, but it can also affect colored Phormium hybrids.
Many plants will revert only on the stem, branch or other areas like that, and these can be cut off to prevent reversion on the entire plant. This typically works to slow the production of green leaf cells.
While it may not stop the reversion process completely, it can help prolong the variegated look for a bit longer. This can give your customers time to either have new variegated plants planted elsewhere in the landscape, start new with non-variegated plants in the same area or embrace the bright green plants that will soon take the place of the once variegated ones.