The planet is dying of thirst. Monthly water charges, once costing pennies per day, are soaring. Water restrictions, once limited to car washing, are exploding. As the planet grows ever more parched, water wars, once isolated skirmishes, are erupting all over the world from the Central Valley in California to sub-Saharan Africa to the Australian outback. And we gardeners, lovers of lush lawns and English cottage gardens, will be forced to rethink and redesign our gardens, replacing our water guzzlers with plants that thrive in dry conditions. Fortunately the plant kingdom is rich with flowering perennials that tolerate drought, and horticulturists who tinker in the plant world are creating new cultivars daily expanding the realm. Following are some ideas to begin the discussion of a reimagined garden of sun-loving perennials that need minimal water. As an added bonus most of them attract butterflies or birds or both – Mother Nature has generously provided for her flying friends.
In addition to designing a drought-tolerant garden another challenge is to create a garden that changes and delights throughout the growing season. With those two goals in mind one of the gardener’s first choices must be the early blooming Penstemon digitalis whose stems are covered with white tubular flowers in mid spring throughout most of the country (USDA Zones 3-8). Lasting well into summer this native has long been a favorite to anchor the back of the garden, and if you’re a fan of the “Wow” factor choose the dramatic cultivar ‘Husker’s Red’ whose white flowers sparkle against its red stems and deep maroon leaves.
Blooming a little later in spring the Mulleins are short-lived but self-sow readily in USDA Zones 5-9. Although the springtime bloom lasts only from June to July, your Verbascum may produce a second flush of flowers in the fall. For those gardeners mourning the demise of a cottage garden as water restrictions tighten, you’re in luck; Verbascum ‘Southern Charm’ with its pastel blossoms in lavender, buff, cream and rose hues loves dry soil and is an old time favorite for the center of a cottage garden.
If your taste runs to hot colors select V. ‘Carribean Crush’ a tropical mélange of orange, yellow and mango shades.
Closer to the front of the garden and blooming at the same time as Verbascum, Savia x sylvestris ‘May Night’ quickly forms a thicket of deep violet spikes that top out at about 18 inches in May and June in USDA Zones 4-8. If you are diligent and dead head you may get a second flowering of this fragrant beauty later in the season just in time to attract birds and butterflies on their way to warmer climes. A favorite of the Royal Horticutural Society, many Salvia cultivars, including ‘May Night’, have been honored with the Society’s Award of Garden Merit.
Summer is the season when those perennials that love it hot, dry and sunny put on their best performances, and one of the longest blooming is Yarrow, or Achillea millefolium producing non-stop flowers from June through September. Known as the “Nosebleed Plant” for its reputed ability to staunch the flow of blood, it is named for Achilles who recognized its medicinal power and used the plant to heal his warriors’ wounds. Although most gardeners are familiar with the yellow version of Yarrow, there are many varieties available from subtle pastels to hot and steamy colors like ‘Paprika’.
If you garden anywhere from the desert to the high Rocky Mountains in USDA Zone 3-9, this is a plant that cries out for a spot in your water-wise garden.
Another long lasting summer bloomer, the North American native Agastache or Giant Hyssops also boasts cultivars in a variety of colors, and one of the most prized is ‘Blue Fortune’ whose soft powdery blue spikes rise above licorice-scented dusty green leaves.
Although more tender than other drought-resistant flowering perennials (USDA Zones 6-9), if you can provide a sheltered site at the back of the garden, it merits a try; it is beloved by gold finches as well as bees and butterflies.
Speaking of butterflies Asclepias tuberosa is a must-have perennial in any drought-resistant garden since it provides food for the endangered Monarch butterfly.
Named for the Greek god of medicine, Butterfly Weed blooms from June to August throughout most of the country, but site it carefully; Asclepias has a long tap root (hence the species name, tuberosa) and resents being moved once it has settled in. As a tribute to the critical role it plays in the life of a Monarch butterfly, A. tuberosa was named Perennial Plant of the Year in 2017.
If your garden cries for a shot of yellow, one of the most reliable perennial flowers is Thread Leaf Coreopsis, or Coreopsis verticillata, a member of the Sunflower family. In addition to lean, dry soils, this versatile plant tolerates the heat and humidity of northern Florida as well as the chilly temperatures of southern Maine and all across the country from USDA Zones 3-9. Coreopsis blooms from June through September, but shear it back in late summer for a second burst of flowers in the fall. If your garden is dominated by soft pastels choose the pale yellow variety ‘Moonbeam’
or if your garden tends to hot and steamy colors the bright yellow ‘Zagreb’ can hold its own.
Although most gardeners are familiar with Purple Cone Flower, Echinacea purpurea, horticulturists are busy developing many new cultivars, including a recent introduction, ‘Cheyenne Spirit’ a bright coral variety that blooms from June through August.
A low maintenance perennial the Cone Flower flourishes in USDA Zones 4-9, and within that range the brown center cones are a big draw for the three “Bs”, birds, butterflies and bees. In addition the plant has substantial commercial value; today Echinacea products contribute over $100 million to the pharmaceutical industry, but Native Americans were well aware of its medicinal benefits centuries before now.
Every garden needs a bright white flower to add punch to the pastels or calm the vivid riot of color, and the Shasta Daisy capably fills that role in a dry garden.
Developed by Luther Burbank in the 1890’s and named for the snow on Mt. Shasta in California, Leucanthemum x superbum (USDA Zones 5-9) can grow as tall as four feet with a two foot spread, but despite its height this plant needs no staking. To brighten a mid-summer bouquet choose ‘Becky’, a handsome cut flower variety that was elected Perennial Plant of the year in 2003.
The final choice for a drought-tolerant perennial garden, Russian Sage creates an airy blue cloud from July through the first frost. In spite of its common name, Perovskia altriplicifolia is not native to Russia at all, but to Central Asia, and in this country it is hardy from USDA Zones 5-9. Topping out at about 4 feet, this delicate-looking but sturdy plant commands a spot at the rear of the garden, and to restore its strength cut it down to the ground in late winter. A well-loved cultivar, ‘Blue Spire’ was honored by the Royal Horticultural Society with the Award of Garden Merit.
So plan today to create a drought-resistant garden for that inevitable tomorrow when the water wars heat up and the restrictions come down. Design the bones, fill in the spaces and disconnect the irrigation system.
High Country Gardens