A tapestry of green foliages for the woodland garden: Maidenhair fern (Adiantum venustum) with the mottled leaves of Trillium luteum, and the glossy, strappy leaves of the perennial Clintonia umbellata, shown here in the Miller Botanical Garden.

This fence stretched around a cottage-style garden that was in riotous color during my midsummer visit. The color of the fence is what made it work. No other color, not even the traditional white, could have blended and softened those flower colors. Just as a green fence corralled all the colors into a whole, so does green foliage in the garden unify as well as enliven.

While green flowers are a captivating oddity, it is the green of leaves and needles that counts every day of the year. It seems that we concentrate on finding space for silver, yellow, purple and variegated foliage. The funny thing is that all these lively and disparate foliages are knitted together and made beautiful by plain old solid green.

Of course, there is nothing plain or often even solid about green. Green can be steely cold, nearly blue or yellow, two-toned, or soothingly deep and mellow. Maybe all gardeners should set themselves the task of making an all-green garden, playing with nuances of texture and shading. Or at least study those elegant all-green French or Italian gardens. There is something to be said for learning the subtle arts before adding all the fireworks.

Green clothes the architecture of the garden, thus creating its shape and form. It could be said that all the other colors serve as nothing more than distractions from this original gemstone of a color, have little role in garden-making besides embellishing or distracting from the primary green.

Painter Robert Dash, in his book "Notes From Madoo," writes, "My heart leans on green, for it is a world-class color, at once oasis and Eden," and describes his ideal garden as a great green house of grand green rooms roofed by the light of the sky. He also makes the point that green should be appreciated for more than its visual appeal. Green is the barometer of a garden's health. Rich, healthy green allows you to relax in a garden, knowing it is well cared for and thriving.

Green is the continuance between garden and borrowed landscape; lift up your eyes from your own garden to the horizon and make full use of green's potential for connectivity. One way to do this is to pay close attention to green's lightness or darkness: It is possible to guide the eye from the dark green needles of pines and firs to the dense, shadowy green of a yew hedge, which in turn makes a perfect foil for brighter or lighter flower colors.

Most of all, green provides an education in the use of texture. Green can be fluffy and feathery as in fennel, tough, leathery and almost ominous in a broad splay of gunnera leaf, neatly pleated as in a spray of fern frond. Think of the silky droop of Solomon seal, the rich luxuriance of cushiony moss or fat hosta leaves, the cunning of baby tears. Some of my favorite green foliage plants are absolutely the easiest to grow - lupines, spiny Eryngium giganteum, hellebores, and the cupped leaves of lady's mantle, shaped to hold a raindrop to reflect their chartreuse softness.

What I love most about green is that it is both elegant and yet supremely pure and simple. Green can be as formal as a clipped shrub in a terra-cotta pot or a series of tidy hedges, but it is also pastureland in the spring, the curve of zucchini in the vegetable garden, the moss, ferns and imposing canopy of our rain forests. And all these shades and reverberations of green-ness are available to us in the ornamental plants we use to shape our gardens.

Valerie Easton is a horticultural librarian and writes about plants and gardens for Pacific Northwest magazine. She is co-author of "Artists and Their Gardens," due next month from Sasquatch Books. Her e-mail address is vjeaston@aol.com