Epimedium alpina ©2001
Epimediums & Companions for Dry Shade
When the shade is produced by native conifers, roots offer competition and the plants have to be tough.
by Phil Wood
Dry shade challenges gardeners but offers opportunities to grow many intriguing groundcover plants. When the shade is produced by native conifers, roots offer competition and the plants have to be tough. Consider plants from the barberry family, Berberidaceae, which offers beautiful and useful plants, both native to our area and from other parts of the world.
Epimedium rubrum with its bright spring foliage.
Epimedium pinnatum sbsp. colchicum grows well on the north side of a house under a redflowering currant (Ribes sanguineum).
Epimedium rhizomatosum flower with long spurs.
Vancouveria hexandra ©2005
The genus epimedium contains many garden worthy plants from a large area, stretching from the eastern Mediterranean to Asia. They grow 12 to 15 inches in height and make a dense groundcover. Once established, many will do well with very little summer water, especially those from Europe and Asia Minor. New varieties are coming from modern plant explorers searching in China. These Chinese species may need more summer water when planted in our dry summer region—the high mountain valleys from which they come receive summer rains, so plant the Chinese species where they will get irrigation.
Epimedium pinnatum subsp. colchicum, from the Caucuses and Turkey, performs very well in my Seattle garden. Placed on the north side of the house, it gets no additional summer water. The evergreen leaves look good year round. Butter yellow flowers appear in early spring.
Epimedium perralderanum is another good evergreen, yellow-flowered epimedium. A similar cultivar, Epimedium x perralchicum, is a cross between the two species already mentioned. ‘Frohnleiten' is a selection of Epimedium x perralchicum with red-flushed new leaves.
Epimedium x versicolor‘Neosulphureum', and a similar plant, ‘Sulphureum', have yellow flowers too, and red flushed new foliage. They are hybrids between E. grandiflorumfrom Asia and E. pinnatum colchicum.
For orange-red flowers, check out Epimedium x warleyense. In spring the new leaves emerge with a red flush, then turn to green. The plant is a hybrid of E. alpinum from southern Europe and E. pinnatum colchicum. Epimedium x warleyense ‘Orangekonigen' has paler flowers than the species.
The green leaves of Epimedium ‘Black Sea' turn purple-black in the fall with the onset of cold weather, with pale yellow and orange-red flowers in spring.
Semi-evergreen and needing some summer water, Epimedium x rubrum has rose red flowers and red-flushed foliage. The leaf color is more intense in full sun.
Most of the European and Asia Minor epimediums will take full sun if given extra summer water. Remove the leaves of deciduous epimedium as it dies down. The foliage of evergreen epimediums looks tattered before the end of winter; cut it back in January or February so the new leaves grow up cleanly. This cutting back also lets the spring flowers stand out without getting lost in the leaves.
Vancouveria, inside-out flower, is the little cousin of the epimedium. Also in the barberry family, the three species in the genus are all native to the west coast of North America. They make good groundcovers for dry shade. Vancouveria hexandra is native to Washington and Oregon. It grows 12 inches high and carries white flowers in spring, thriving in shade or part shade and is drought tolerant once fully established. The foliage is semi-evergreen. Shear it back when it looks ragged in winter.
The two evergreen species are Vancouveria chrysantha, with yellow flowers, and Vancouveria planipetala with white flowers. Both are native to southern Oregon and northern California. V. chrysantha is the most drought tolerant of the three.
Mahonia nervosa, low Oregon grape, is another barberry relative native to the northwest and is small shrub instead of a perennial, having woody stems and evergreen leaves. The yellow flowers appear in spring on this two-foot shrub that thrives in part or full shade. The leaves look like prickly holly leaves. For a sunnier location, plant Mahonia repens, creeping Oregon grape. The leaves are more rounded than M. nervosa and the plant is lower, to one foot. The foliage turns bronze in winter.
Add foliage contrast with a few companion plants from other plant families. Iris foetidissima, gladwin iris, from Europe, provides strong linear form that complements the rounded form of the plants previously discussed. It is a strong performer in dry shade and produces seed capsules that split to reveal bright orange seeds. Plant the cultivar ‘Variegata' for clean looking green and cream spikes of foliage.
Throw some more northwest natives in the mix. Pacific Coast irises are hybrids of several native species and provide flowers in many colors for dry, partialshade. Another flowering native perennial, with a ferny texture to compliment the blade shaped iris leaves, is western bleeding heart, Dicentra formosa. Add a third texture with false solomon's seal, Smilacina racemosa, with its double ranked leaves and fragrant white blooms at the tip of the plant, which give way to red berries.
Once you get these started by giving some summer water for the first few years, you will have a planting offering interest and change throughout the seasons.