Plant splashes of purple throughout the garden

I love plants with purple foliage. They are equally capable of promoting peace or inciting a riot in the garden. Ease the harshness of red flowers with neighboring plants with purple foliage. Or create theatrical combinations when plants with purple foliage are paired with plants boasting yellow or orange blooms.

Purple foliage looks even darker when it is planted near plants of high contrast, like annuals or perennials with silver foliage. Or achieve a gentler effect when purple is mingled with pastel-colored blooms. There is a plethora of annuals and perennials offering purple foliage. Here are just a few.

Install purple carpet in the garden with Ajuga. Commonly known as carpet bugle, it has many cultivars with purple foliage. Catlin's Giant is one of the largest growing 6 to 8 inches tall. Chocolate Chip is one of the smallest remaining a ground-hugging 2 inches. Create a stunning combination by planting either under large gold-leaved hostas or the Aralia Sun King.

Choose one of many varieties of coleus with purple foliage. Some are solid-colored; others edged in lime, gold or red. Some feature large leaves; others small, intricate foliage. With varieties for sun or shade, every garden or container needs at least one (or ten).

Purple Knight Alternanthera has striking dark purple foliage when grown in full sun. Let its color and texture trail over the edge of large containers. Another trailer, Purple Queen Setcreasea, has broad, deep purple leaves, ideal for containers, hanging baskets or as a ground cover in full sun to light shade.

Chocolate Eupatorium has clusters of white flowers in September and reaches 3 to 4 feet tall. It is best grown in full sun with consistent moisture. Without a constant supply of water, site it in light shade. It is spectacular paired with blue-foliaged plants.

Sedum has several purple-leaved cultivars. Smaller varieties are best for edging; taller types are ideal for the middle of a border. All are low-maintenance plants and prefer a hot, dry location.

Hillside Black Beauty bugbane has dark purple, fern-like foliage. Growing up to 7 feet tall, it carries 12-inch spires of ivory white flowers in September and October. It may take some searching to find this perennial and it can cost a pretty penny, but it is well worth the time and money to include this stunning specimen in the landscape.

The family of coral bells (Heuchera spp.) may offer the most cultivars of perennials with purple foliage. The foliage of Obsidian resembles purple satin; the leaves of Midnight Rose are splashed with rose-pink; and the foliage of Amethyst Mist is overlaid with silver. Coral bells perform best in filtered light all day or morning sun and afternoon shade.

The danger when planting purple-foliaged plants is overdoing it. Using too many can create a black hole in the garden. Instead, strategically position small groups in different areas in the landscape to provide continuity, to give the eye a path to follow as it moves across the garden.

• Diana Stoll is a horticulturist, garden writer and speaker. She blogs at gardenwithdiana.com.