Small Backyard Designs: Great Groundcovers for Your Seattle Garden

By Janine Anderson, CPH
Professional Member, APLD

Although often overlooked, groundcovers can play an important role in a landscape. Not only do they provide a backdrop against which to showcase larger plants, they also knit together the various elements of a composition. They are useful for weed suppression and erosion control and provide cover for birds and beneficial insects.

Groundcovers can be evergreen or deciduous. Some are suitable for sun, others for shade. Some require regular irrigation, while others prefer drier conditions. Many adapt to a variety of situations. This article introduces several of the many fine candidates for various scenarios, and all are under, or can be easily maintained under, two feet in height.

Soaking Up the Sun
Many groundcovers are evergreen so will cover the ground year round. Among these is Mount Vernon laurel (Prunus laurocerasus ‘Mount Vernon’). This variety of English laurel stays under two feet tall, and despite its slow growth rate, it gradually expands to cover an area five feet in diameter, weaving around and complementing larger plantings.

Mount Vernon laurel (Prunus laurocerasus ‘Mount Vernon’). Photo courtesy of Pat Breen, Oregon State University

Among the numerous evergreen conifers that make good groundcovers, Siberian cypress (Microbiota decussata) is an easy, effective groundcover whose sprays of lacy, scale-like foliage radiate out from its center. It can reach eight feet in diameter while staying under two feet tall.

Siberian cypress (Microbiota decussata). Photo courtesy of Pat Breen, Oregon State University

Many varieties of juniper perform well in sunny sites with well-drained, sandy soil. Some of the loveliest are shore junipers. Juniperus conferta ‘Blue Pacific’ is a dwarf selection that reaches one foot tall and spreads to six feet. Native to the sea coast of Japan, it has feathery blue green foliage and gray berries.

Shore juniper (Juniperus conferta ‘Blue Pacific’). Photo courtesy of Janine Anderson

Though another conifer, Podocarpus ‘Blue Gem’, can reach four feet tall, pruning can keep it below the two-foot threshold. This cooperative, blue-needled shrub is both easy and interesting, making it worth the small effort required to keep it at two feet. Blue Gem is adaptable to a variety of conditions, including some shade.

Podocarpus ‘Blue Gem’. Photo courtesy of Janine Anderson

Evergreen “creepers” that are content in full sun include ornamental strawberry (Frageria chiloensis), creeping Taiwan bramble ( Rubus rolfei), and barren strawberry (Waldsteinia ternata ). All of these have attractive foliage, flowers, and berries. The bramble and ornamental strawberry have white flowers, while those of the barren strawberry are a cheerful yellow. A word of caution: Taiwan bramble is a tenacious groundcover that can spread to 12 feet of more, so make sure you want the coverage it will provide.

Creeping Taiwan bramble (Rubus rolfei) cascades down rock wall and provides lush green backdrop for foreground plantings. Photo courtesy of Susan Picquelle

Two evergreen groundcovers with shrub-like forms that are effective massed, as hedges, or edging walkways are wall germander (Teucrium chamaedrys) and sun rose (Helianthemum nummularium). In the mint family (Lamiaceae ), wall germander gets only a foot or so tall, and its magenta flowers are attractive to bees. Although evergreen, it tends to look best if cut back in early spring to keep it from getting leggy. Sun rose has a more relaxed habit, enabling it to cascade over a wall. The flowers of its several varieties come in tones of yellow, pink, rose, peach, and bright orange. As with wall germander, judicious trimming can keep sun rose dense and compact rather than leggy.

Flowering wall germander (Teucrium chamaedrys) flanks granite risers. Photo © Doreen Wynja

Cool in the Shade

Pachysandra , a groundcover often planted in shady areas, became a lot more interesting after plant explorer Dan Hinkley introduced the variety ‘Windcliff’ into the market. In full to light shade, this stoloniferous stunner has fragrant white flowers in early spring and then again in autumn. Its blanket of evergreen foliage reaches four to six inches tall. Another Hinkley introduction for shade, Beesia deltophylla, is an evergreen clumper with lustrous heart-shaped leaves and wispy spikes of small white flowers in early summer.

Older dark green foliage along with fresh, bright green spring leaves of Pachysandra axillaris ‘Windcliff’. Deeply lobed leaves are from evergreen vine (x Fatshedera lizei ‘Annemieke’) that scrambles through garden bed. Photo courtesy of Janine Anderson

The six-inch-tall Himalayan maidenhair fern (Adiantum venustum) is an evergreen groundcover that slowly colonizes an area of about three feet wide. You will enjoy its emerging bronzy fronds most if you cut off the previous year’s foliage in January. In spring, the foliage turns bright green.

Fresh, bright green fronds of Himalayan maidenhair fern (Adiantum venustum) below dark green column of Azara microphylla. Photo courtesy of Janine Anderson

Some small, shade-loving groundcovers can become dense carpets or weave around pavers. Two of these are brass buttons (Leptinella squalida ) and alpine water fern (Blechnum penna-marina). Both of these little gems stay under five inches tall and can take some foot traffic. Brass buttons has green tones of feathery, fern-like foliage. Alpine water fern is a true fern for moist, shady sites. It grows slowly, eventually reaching four feet in diameter. It performs best with moisture-retentive soil and regular summer water.

Grasses, Vines, Sedums, and Herbs

Many other plants, including grasses, vines, sedums, and herbs, can make excellent groundcovers. Among these are mondo grass (Ophiopogon japonicus), which has dark green, grass-like evergreen leaves and produces tiny spikes of lilac flowers. Vines, such as the Fatshedera shown in the Pachysandra photo, can often do double duty as groundcovers, weaving around shrubs and trees. The very fragrant star jasmine vine (Trachelospermum jasminoides) makes a good groundcover as well.

A sea of mondo grass (Ophiopogon japonicus) borders path and unifies garden elements. Photo courtesy of Janine Anderson

Creeping sedums and herbs such as thyme and oregano are great for planting below shrubs, between stepping stones, and along walkways. They require sun and will not tolerate wet sites.

This medley of sun-loving, drought-tolerant groundcovers comprises two succulents, Sedum reflexum ‘Blue Spruce’ (left) and Sedum spathufolium ‘Cape Blanco’ (top), and two thymes, the flowering Thymus praecox ‘Coccineus’ and the nearly flat mat of Thymus serpyllum ‘Elfin’ (bottom). Photo courtesy of Janine Anderson

Conclusions

When starting a new garden or renovating an existing one, don’t forget to add groundcovers to your list when you visit the nursery. These small wonders can be the finishing touch you need for an inspired composition.

If all this seems overwhelming, seek out a landscape designer for assistance.