It needn't be so.

One problem might be in how you define a border. The best ones, you may assume, use only perennial plants, but deciduous and evergreen shrubs have long been acknowledged as options.

Even in publications devoted to gardening, it's not uncommon to see photographs of borders that include shrubs among the billowing bee balm, daisies and phlox.

The benefits of integrating small shrubs into a border are many. Not only do they not require the dividing, staking and deadheading of perennials, but they maintain their form and foliage throughout the season.

While some flowering shrubs bloom for only part of the time, the foliage typically shines.

In the winter, dwarf conifers and broadleaf evergreens are attractive throughout, a big improvement than a long, wide border of flattened and cut-back perennials.

What shrubs work best in a perennial bed? Size is sometimes a consideration, but plant breeders have new compact shrubs that offer many options.

Shape is also a consideration. Some tend to be low and spreading; others are upright and still others form dense mounds or grow in a loose fountain shape.

Well-designed borders will rely on more than color, their contrasting features, shapes and sizes all contributing interest.

Upright growing shrubs

An upright-growing shrub can become a focal point or the beginning of a path; several at the back of a border can create a strong backdrop for shorter perennials.

One good choice is the Dwarf Russian Almond (Prunus tenella), which has pink flowers in May and small, red fruit (which birds love) in July.

Another option Is the "Autumn Magic" Black Chokeberry (Aronia melanocarpa "Autumn Magic"), with fragrant white flowers coming in spring, glossy leaves in summer, brilliant red leaves in fall and black berries for birds.

Mock Orange in a small-scale, fragrant version (Philadelphus "Miniature Snowflake") is a relatively new introduction, dotted with small, white double flowers in June.

Mounding Shrubs

A mound seems to work well in the middle or front of a border, offering a smooth transition from one section to another.

One choice, St. John's Wort (Hypericum kalmianum) provides a burst of bright yellow in July and August, with blue-green leaves that complement the blooms.

"Carol Mackie" Daphne is a highly fragrant shrub that has leaves outlined with a thin, cream-colored margin and pink flowers in May and June.

Potentillas is a species with which breeders have been tinkering for years. The result is a number of versions that offer relief from the yellow that was once omnipresent. Today gardeners can choose from a wide range of colors. The potentillas bloom from June to September.

Arching Shrubs

With Long, flexible stems of fountain-shaped or arching shrubs, these offer drama and movement to a plant combination.

Smoothleaf Snowberry (Symphoricarpos) works well as an accent plant at the back of a border. Plants have dark green leaves on arching branches, pink flowers in June and tight clusters of opaque white berries in August.

Japanese Kerria (Kerria Japonica) have double], yellow flowers from June to August, with green stems adding color to the winter landscape. They do, however, sucker.

Spreading, prostrate shrubs

Low growers work best in front, knitting a section to the next and helping guide the eye through the space.

Deciduous Cotoneasters (Cotoneaster cvs.) is a highly abundant species, one of the smallest being the early creeping cotoneaster, with glossy, tiny, round leaves that turn bright red in fall. Birds will snack on the red berries that follow.

Spreading Junipers (Juniperus cvs.) are not just for foundation plantings but can be refined enough for an elegant border.

Cutleaf Stephandra (Stephanandra incise "Crispa") has graceful branches with leaves finely cut like a fern. It produces white flowers in June.