Groundcover plants perform a wide variety of “services” in the landscape, ranging from erosion control to acting as living mulch, and even providing color and texture in hard-to-access areas where maintenance can be a challenge. Then there’s simply filling the space with lush, green and often colorfully blooming plants.
More and more, however, groundcovers are becoming the responsible citizens of the landscape, supporting efforts to reduce supplemental water usage. Once many of these plants have become established, they require considerably less water to maintain a healthy presence and, in some cases, can thrive on rainwater alone.
It’s no secret that much of the West is struggling through historic, multiyear drought; in a relatively new twist on weather reports, we’re hearing not just about the geography, but the population affected. In the case of the Western states, the U.S. Drought Monitor claims that that’s 54,919,681 people. In California alone, state-mandated restrictions require a 25 percent reduction in water use. Part of Governor Jerry Brown’s mandate requires 50 million square feet of lawns throughout the state be replaced by drought-tolerant landscaping. Good move.
Sooner or later, no matter where they live, clients and customers will ask for plants that can handle periods of aridity. And that’s where many groundcover selections can fit the bill.
Arenaria ‘Wallowa Mountain’ (Wallowa Mountain desert moss, aka sandwort; also called ‘Wallowa Mountains’) is a native, xeric selection from the Wallowa Mountains in Oregon that performs beautifully from West to East in sandy to average soil; it prefers full morning sun and afternoon shade. Some believe it does best only in Western sites, but there’s a lovely planting in the Allen Centennial Gardens in Madison, Wisconsin, where the accompanying picture was taken by Plant Select executive director Pat Hayward. Wisconsin = hot, humid summers, a far cry from the high desert west of the Great Divide.
This exceptionally low-growing, velvety, mat-forming plant reaches only one-half to 1 inch tall and spreads to about 14 inches. The bright green, tiny foliage resembles moss, yet it’s decidedly drought-tolerant. A few small white flowers appear now and then, but relative to the evergreen expanse, they’re insignificant.
This Arenaria is hardy in zones 4 to 8, performs nicely in sun, partial sun and shade, and needs very little water once established.
Artemisia versicolor ‘Sea Foam’ is a vigorous groundcover with soft, lacy foliage that’s an eye-catching silvery blue. Mature height is about 8 to 12 inches, and the plant spreads to about 24 inches in sun, partial sun and shade. Good for the Xeriscape garden, it’s also a trouper in gardens located in deer country – yet another xeric groundcover that’s deer resistant.
‘Sea Foam’ is hardy in zones 4b to 8, and performs well in clay, loam and sandy soils, where it provides winter interest.
Callirhoe involucrata (winecups) announces its presence in the dry landscape with brilliant, wine red flowers that bloom from spring through hard frost. Reaching only about 6 to 8 inches tall (but spreading up to about 30 inches), this native groundcover thrives in a Xeriscape setting and at the front of the border, soaking up full sun. (It also will perform well in partial sun to shade.) It’s hardy in zones 3 to 9 and prefers a loam soil, although it lives well in rocky soils in prairie locations in the wild.
Winecups is a member of the mallow family (Malvaceae), which is evident in the cup-shaped, five-petaled, poppy-like blooms.
Delosperma (ice plant), like Callirhoe, is proof positive that groundcover plants can provide brightly colored blooms as well as ground protection and water savings. Daisy-like flowers – some reaching 2 inches across – cover this exceptionally low-growing succulent throughout spring, covering the tiny leaves with an array of colors. Red Mountain Flame (Delosperma dyeri ‘Psdold’), pictured here, virtually glows a fiery crimson. Other selections from Plant Select include purple Table Mountain, Lavender Ice, orange and purple Fire Spinner and a blush Mesa Verde, among others.
Ice plant reaches only about 1 to 2 inches tall and spreads up to 18 inches in zones 5 to 8; it loves the sun but will perform nicely in partial sun to shade, as well. Tolerant of a wide range of soils, it is deer resistant and provides winter interest.
Marrubium rotundifolium (Silverheels horehound) is actually from Turkey, but was adapted to become a reliable, “eversilver” groundcover that is part of the PlantSelect collection. It’s a vigorous, mat-forming plant that’s hardy in zones 4 to 9 and does best in full, Western-type sun – this plant loves it hot and dry. It thrives in a variety of soil types, ranging from clay to loam to sandy.
The bright green foliage is rounded and softly felted, but the best part is the silver lining that shimmers and glows, giving silverheels its distinctive aura.
Reaching only about 2 to 4 inches in height, silverheels horehound forms a mat that spreads up to about 36 inches. Plus, it’s deer and rabbit resistant.
Teucrium chamaedrys ‘Prostratum’ (prostrate germander), native to rocky, dry, Mediterranean hillsides, reaches only about 6 to 8 inches tall, but spreads to nearly 4 feet in a densely mounding habit. It’s a tough evergreen plant with small, deep green, glossy leaves that feature serrated margins. In spring and summer – and into fall – flower spikes boast small, pink to lavender to purple blooms. The plant prefers well-drained soils, but once it’s established, it’s a reliable addition to a xeric landscape and is hardy to Zone 6.
Prostrate germander prefers full sun, and the plant responds well to occasional deadheading and a reasonable overall pruning in late winter.
Zauschneria garrettii ‘PWWG01S’ (Orange Carpet hummingbird trumpet) is an outstanding and colorful groundcover that spreads rapidly to about 24 inches (with a height of 6 to 8 inches) in sun, partial sun to shade in zones 3 to 8. Masses of dramatic, orange-red, trumpet-shaped blooms cover the plant from mid- to late summer, attracting hummingbirds and pollinators to help spread the wealth. This dazzling plant is an outstanding selection for high country gardens, and performs well in clay, loam and sandy soils.
Woody plants to the rescue
A number of woody plants qualify as groundcovers, providing much needed soil stabilization as well as requiring very little maintenance. Once many of these low-growing shrubs are established, their thirst also is reduced to a trickle – in some cases, rainwater is all that’s needed.
Sumac is an excellent example: Rhus trilobata ‘Autumn Amber’, a selection developed in New Mexico, provides beauty and toughness for challenging sites. A Plant Select choice introduced in 2014, this low-growing shrub reaches 6 to 18 inches tall and can spread 6 to 8 feet serving, for all intents and purposes, as a beautiful form of living mulch. Give it room to grow and it’ll cover the space; it’s also easily kept in bounds with a hand pruner.
Creeping branches hold glossy, bright green, dramatically lobed leaves that turn amber to reddish in fall.
Best of all, this Zone 4 hardy shrub requires little water once it’s established, and is considered a xeric selection.
Evergreen groundcovers are an unbeatable way to provide protection and color year round, and Monrovia’s Alpine Carpet juniper (Juniperus communis ‘Mondap’) is a fantastic, blue-green candidate. It’s a slow grower that reaches only about 8 inches tall, but spreads to about 3 feet in full sun in zones 3 to 6, and it’s one of the company’s “waterwise” selections. Only occasional moisture is required once the plant is established. Alpine Carpet is tolerant of extreme cold and humidity, and it’s deer resistant. This plant thrives in rocky, thin soils and can be used for erosion control on difficult slopes.
Then there’s manzanita (Arctostaphylos × coloradoensis), an evergreen shrub that requires very little water once established in the landscape. Plant Select offers three Colorado natives – ‘Chieftain’, ‘Panchito’ and mock bearberry, which, according to Pat Hayward, resembles its relative, kinnikinnick, but with more “presence” and less thirst.
‘Panchito’ (pictured here) grows to about 10 to 14 inches tall and spreads to about 36 inches in sun, partial sun and shade, and offers very small, waxy, white to light pink flowers from February through April. On mature plants, these are followed by small red berries. This deer-resistant shrub grows in both loam and sandy soils in zones 4b to 8.
Fast-growing, Australian native Eremophila glabra ‘Mingenew Gold’ (Outback Sunrise emu) has been tried and tested in extreme heat, and it’s one of Jeff Grass’s recommendations for an arid-setting groundcover. Grass is the Arizona and New Mexico sales rep for Mountain State Wholesale Nursery in Arizona, where high temperatures and low moisture are the norm.
This durable evergreen thrives in full sun and reflected heat, which means it loves to be planted in difficult sites, such as along roadways. It also does well in part shade and is hardy in Zone 8. At maturity, the plant stands only about 1 foot tall, but spreads 6 to 10 feet. Masses of yellow, tubular flowers cover the plant in spring.