Outside Plants That Make Great Borders

Spring

• For early color, plant creeping phlox (Phlox subulata) at the edge of a border. This trailing perennial grows to 9 inches tall and blooms with white, pink, blue and purple blossoms. It prefers sunny, well-drained sites. Cosmos (Cosmos spp.) bloom from spring through fall in a range of colors. These annuals grow from 3 to 6 feet tall and thrive in sun. Ornamental grasses make good border plants. Blue oats grass (Helictotrichor sempervirens) grows in 30-inch clumps of silver-blue foliage and produces 2-foot-tall flower stalks in late spring. It thrives in sun to partial shade and moist soil.

Early Summer

• Dianthus or pinks (Dianthus spp.) add color and scent to a border. These perennials bloom through early summer with pink, rose and white blossoms and grow to 2 feet tall. They prefer sunny, well-draining soils with a slightly high pH. Perennial astilbes (Astilbe x arendsii) also bloom in early summer. They produce pink, red and white flowers and grow from 1 foot to 4 feet tall. Astilbes grow well in partially shaded, moist sites. Annual bachelor buttons (Centaurea cyanus) bloom in early summer with white, blue, pink and burgundy flowers. These 3-foot-tall plants prefer moist soil in sun or partial shade.

Summer

• For midsummer color, plant blanket flowers (Gaillardia x grandiflora). These 3-foot-tall perennials bloom with yellow and red multicolored blossoms and thrive in sunny, dry sites. Cardinal flowers (Lobelia cardinalis) bloom with red spikes in late summer. They grow to 4 feet tall and prefer shady, moist sites. Annuals for summer color include agerathums (Ageratum houstonianum), 6- to 24-inch-tall plants that produce white, pink and blue flowers. They grow well in sun to partial shade and tolerate some drought.

Fall

• You can still have colorful borders into the fall. Plants with fall interest include Mexican or velvet sage (Salvia leucantha), a 3-foot-tall perennial that blooms with spikes of deep-pink and white flowers. It prefers sunny, well-drained sites and has aromatic, gray-green foliage. Lantana (Lantana camera) blooms into fall with orange, pink and yellow blossoms. It thrives in sunny, dry sites and grows to 12 inches tall. Fall-blooming annuals include snapdragons (Antirrhinum majus), which grow from 6 inches to 3 feet tall and thrive in sun to partial shade. They come in a range of colorful cultivars.