Variegation often follows the natural geometry of plant foliar tissue, producing lines, veining, splashes, and edges of symmetrical elegance, as in the white-margined holly Ilex aquifolium 'Argentea Marginata'. But it also expresses itself in masterpieces of irregularity, like the creeping Houttuynia cordata 'Chamaeleon', whose surreal smorgasbord of yellow, green, pink, red, and bronze would give Picasso pause. Technically, variegation signals some level of interference with a plant's ability to photosynthesize food. Gardeners simply can't resist sheltering and propagating these polychromatic, many-patterned wonders and blunders, and adding them to the horticultural palette. We've often heard the adage that variety is the spice of life.
Variegated plants are especially useful for adding counterpoint to problematic areas of shade.
What's more, unlike fickle flowers, which generally fade after a couple of seasons at most, variegated foliage can furnish a garden with a year-round carnival of color. For Steve Hass of the Shade Tree Nursery, the appeal of variegation doesn't end here in the arena of simple garden aesthetics. The more time I spend with these plants, the more I appreciate the precision with which they're created, each according to its own. Steve has even evolved a rudimentary cosmology of variegation. So, if you are a closet admirer of variegated plants, take heart.