Do variegated plants live as long as their non variegated coutnerparts?

There is no simple answer to this question.

Plants are variegated for various reasons; some species are variegated as an adaptation, such as Maranta, and they come to no harm. Others have variegated varieties like some agaves, and at least some of those are chimeras, with more than one kind of parent plant tissue making up their leaves. They don't seem to come to much harm either; many of them grow as well as their solid-coloured siblings. As a rule, if they produce viable seeds, the seedlings are single- coloured. However, some plants are mutants that produce little or no chlorophyll, and they either do very poorly or die if not artificially fed sugars.

Another kind of variegation results from a shortage, a deficiency, of certaon foods, mostly mineral elements. Usually this is a shortage of the trace elements iron, manganese, zinc or the major nutrient element magnesium in the soil. If that is so, the plants need a suitable trace mineral (or magnesium) fertiliser.

Sometimes the soil contains plenty of the trace elements, but the plant is unable to absorb such minerals because their compounds in that soil are too insoluble . Then the plant usually needs suitable fungi around their roots to extract the minerals for them.

Shortages of such elements prevent the plant of producing as much chlorophyll as it needs, so the leaves become variegated. Some kinds of virus diseases also produce variegation, and some of them are produced as standard decorative garden varieties.

However, plants that are variegated as a result of viral infection or shortage of vital minerals, are likely to look miserable and do poorly. Many of them will not do well, and may not live as long as healthy plants. Sometimes a plant grown as a decorative variegated garden subject will produce a healthy, plain-coloured shoot , and that shoot is spectacularly healthier and faster-growing than any other part of the plant. This gives some idea of how much harm the infection is doing the plant.

How much that matters is for the gardener to decide; perhaps he or she does not want a vigorously growing or plain-coloured weed, and prefers a miserable, well-disciplined garden subject.

Some other people regard variegation as an offensive sign of ill health. Take your own pick; there is no simple way to settle such matters of taste. But you will very rarely find agricultural plants with any fancy variegation.