It’s showtime in the perennial flower border. The Oriental poppies, pink and blue pincushion flowers, bleeding hearts and hardy geraniums are vying for center stage and each plant is striving to be better than the year before. The bearded iris will return for many years but must be divided and replanted as older parts of the plant die out. A successful perennial border is the reward for all your hard work.
Perennials are nonwoody plants that come back in the garden year after year. Unlike annuals, most of the perennials we plant are hardy. Hardiness is a reference to a plant’s ability to survive the coldest weather of a specific location. Although perennials that are hardy in Southwest Washington typically die to the ground through the winter months, the plant itself is still alive and will return bigger and stronger in spring.
Every gardener has a different idea of the perfect perennial garden. Just as some prefer light opera to country music, a gardener may prefer the blowsy, full-blown look of an English flower border to the sparse suburban penchant for individual plants floating in a sea of bark dust. The wonderful twist to this garden story is that many of the same plants can pull off entirely different garden styles.
The tall, flower-laden stalks of delphinium, rising up in spires of blue, pink or pure white florets, take on the personality of the garden they are planted in. Amid a gathering of complimentary-colored perennials, the delphinium adds stature and grace to the planting mix. In large clusters of 10, 25 or 50, with no other plants but an evergreen backdrop, the look is rich and abundantly generous.
Brunnera macrophylla Jack Frost is the Perennial Plant Association’s 2012 Perennial Plant of the Year. Other common names for brunnera include Siberian bugloss and false forget-me-not because of the plant’s tiny, bright blue flowers that resemble those of the annual flowering true forget-me-not. The flowers stand above the 12-inch-high foliage and the plant spreads to about 20-inches wide. The heart-shaped leaves are frosted silver with a delicate pattern of light green veins. Jack Frost has been one of the best perennials in my garden for many years now.
In general, perennials prefer soil that is well-drained and amended with organic matter. There are perennials for every level of sun exposure. The bright yellow coreopsis will bloom throughout the growing season in full sun if deadheaded as each flush of bloom fades. The equally vibrant Ligularia (The Rocket) can take only tempered sunlight in the morning and evening. These plants would fall over in a faint if made to face the noonday sun.
The easy growing daylilies start to bloom this month but their upright sprays of garden green leaves emerged weeks ago to fill out the early spring flower border. As much as we adore the blossoms of our perennials, the value of the plant’s foliage is paramount to the success of a finished garden look. A plant’s flowers come and go as fleetingly as a celebrity’s star power. The texture of an established garden relies on more than colorful bloom alone.
Many perennials are grown specifically for their interesting foliage. The hosta, beloved by gardeners and slugs alike, can carry a shady border through the growing season with a delightful array of leaf color, texture and form. The variegated hosta Francee and patriot add light to dark areas of the garden. The leaves of Sum and Substance and Inniswood will actually develop richer leaf color if they receive a smattering of sunlight over part of the day.
Shady areas of the garden can be made lighter with the addition of silver- or golden-leafed plants such as Lamium Beacon Silver or L. Aurea. The chartreuse flowering bracts of Euphorbia Robbiae sit atop foot-high, dark green plant stalks. This invasive perennial groundcover grows well in inhospitable locations. Try it at the foot of a Douglas fir where little else will grow. The mottled markings on the leaves of pulmonaria stand out in dappled shade.
All perennials look their best with regular maintenance during the growing season. Deadhead spent flowers to keep the garden looking neat and to prolong bloom. Above all, choose a wide variety of plants that help express your personal take on the garden. The shasta daisy reminds us that simplicity can satisfy the soul. The Japanese anemone is grace personified. Whatever your choices, once established these stars of the flower border will return each year to revive their 15 minutes of fame.
Robb Rosser is a WSU-certified master gardener. Reach him at Write2Robb@aol.com.
