Variegated leaves in garden plants

This scan of several leaves from one stem on a Japanese maple illustrates several aspects of variegation.  Reversion of leaves to solid green plagues all fans of variegated plants- but note that more-green leaves are also often much larger, as well as thicker.  White areas on these variegated leaves show brown tips- sun scorch, even in a mostly-shaded location. (Chlorophyll protects leaf tissues from radiation damage, much as melanin works in human skin and eyes.) Pink areas on the white leaves are aesthetically pleasing manifestations of red anthocyanin pigments (often a stress response in plants generally) that are more visible when not masked by the green of chlorophyll.

Because chlorophyll is necessary for photosynthesis, which produces sugars- in turn the building blocks of starches and cellulose, the major components of leaf structure--- whiter leaves and leaf segments are often thinner and smaller in area.  In addition, when a leaf contains both white and green areas, it may appear crinkled due to the uneven distribution of structural materials.  In this scan, we also see that curvature of lobes is produced- always pointing toward the white side of the white/green division, in which the boundary is usually a vein.

Pale-colored, chlorophyll-poor leaves are, in addition to these structural effects and sun scorch vulnerability, also sometimes more vulnerable to disease and insect predation.  While too much sun can damage them, they also suffer a disadvantage in low-light conditions due to their low photosynthetic capacity.
For these reasons, variegated and variant-color plants, while they can be of considerable aesthetic value in the landscape, may require much more care and may not live as long as the green-leaved species from which they were derived.