You've chosen a site and done the preliminary work.

To paraphrase singer/songwriter Don Henley, we're getting down to the heart of the matter in this series on garden design.

Run for the border

Borders can be as long and wide as you're willing and able to tend. Late English garden designer Gertrude Jekyll's main border at Munstead Wood, for example, was 200 feet long and 14 feet wide. A bit awe-inspiring for those of us who don't own an English country estate.

Romantic, broad borders also were characteristic of Vita Sackville-West's famous English gardens at Sissinghurst and Christopher Lloyd's Great Dixter gardens. What makes these designers and their gardens "classics" is that, regardless of size or shape, plantings were appropriate to the site, rather than a hodge-podge of whatever was in vogue.

What's the difference between a bed and a border? Generally, a border can only be viewed from one side; beds have more than one vantage point. Island beds are surrounded by a sea of lawn, and plants are visible from all sides. A berm is a mound of soil.

The traditional English-style garden border measures 6 to 8 feet wide. In an average American backyard, a border is 2 to 4 feet wide. Sometimes borders bump up against shrubbery or structures such as fences or walls. Leave walking space so you can reach into the border from that side.

It's become popular again to divide a large yard into separate areas linked by paths, structures or plants. Sackville-West was known for her garden "rooms," each planted in a different style, including an all-white garden.

Tux or T-shirt?

In the traditional formal garden, gardeners imposed their will on nature with sharp shears and ruthless pruning. That rigidity has bowed to modern sense and sensibilities. Arrangements are softer and more natural within the confines of straight lines or geometric shapes. The focus is on balance and symmetry.

A selection of herbs is stunning in a formal garden, adding fragrance and textural interest. Low-growing shrubs can be planted as edging. Shrubs make nice backdrops for herbaceous borders. Vines can be grown on trellises and towers for vertical interest.

An informal garden looks spontaneous and natural, but balance and proportion is every bit as important. Usually there are soft, sweeping curves and deep edging. Don't go overboard with too many curves or it could end up looking like Burlington's Snake Alley. Planting is deliberately random, creating a sprawling effect of mass and texture. Fudging on maintenance is fine, but procrastination can turn informality into chaos.

In their groundbreaking book, "Plant-Driven Design," authors Scott Ogden and Lauren Springer Ogden advocate restoring "life-affirming vitality" to garden design and letting plants take the lead. Ultimately, cultivating plants is why we grow gardens. Plants should drive the composition and require equal billing with architecture, art and landscaping.

Start small. You may be lucky enough to have a willing partner to help or at least a kid you can pay to weed. Enlarge a bed or install another one as your interest grows. Consider how many plants you can afford to buy on a budget or try seed starting. Know a gardener? We're a generous lot, happy and willing to share a clump, division or cuttings. I know gardeners whose borders were built on friendship plants.

Reaching critical mass

Select plants sensibly, based on height, habit, form, bloom and leaf color, size of plant at maturity, bloom date and growing zone. We're Zone 4 but aren't above trying a few Zone 5 plants in protected spots. Strive for interest from spring through winter by incorporating bulbs, herbaceous perennials, annuals, ornamental grasses, roses, shrubs, small trees and evergreens into your plan.

Mass: Think clump or drift. A clump is a grouping of odd numbers (3, 5, 7) of plants arranged in a circle. Drifts are groupings arranged in a longer, more irregular shape. The smaller the plants, the more plants you'll need for impact. For best effect, repeat clumps or drifts of the same or similar plants or colors several times along the border. In "The Perennial Garden Design Primer," the authors suggest a staggered or checkerboard placement within each drift. If you have five plants, plant either two or three in front and the rest behind. Then break the pattern in another drift so it's not identical. Try arranging one drift aimed toward the border's outer edge, the next toward the middle or in back to create a natural flow.

Texture and form: Color and blooms are temptresses but lust is short-lived. Many perennials bloom over a two-, three- or four-week period and then it's over. Foliage remains. Shapes are round, heart-shaped, strappy, narrow, broad and pointed. Textures range from fine to coarse. Visually, foliage can make a garden look large or small. Crinkly, coarse or fine and shiny leaves add character. Big, bold foliage lends scale to a large garden; fine- and medium-sized foliage can make a small space look larger. Too much of one texture can look boring or busy.

Next week: Color and perennial pairings

Melody Parker is a master gardener.