An area in my garden is dry and shady. Can you recommend plants to use there as ground covers?
Bridget McManamon, Ashland, OR
The rosette evergreen foliage of Mrs. Robb's spurge thrives in dry shade.
Barbara Blossom Ashmun, a garden designer in Portland, Oregon, responds: Because of the five mature, productive plum and apple trees original to my garden, I’ve become a pro at finding perennials for dry shade. My strategy is to grow shade-loving plants that are normally thugs in rich moist soil but have enough vigor to withstand drought. Plants with deep roots and succulent leaves that store moisture well are also good choices for dry shade.
At the head of my list is Mrs. Robb’s spurge (Euphorbia amygdaloides var. robbiae, USDA Hardiness Zones 6–9). Glossy evergreen leaves arranged in rosettes are topped by columns of bright- yellow bracts that bloom all spring. Mrs. Robb runs quickly underground, but it’s easy to dig out any surplus. Another romper, pink-flowering ‘Claridge Druce’ cranesbill (Geranium X oxonianum ‘Claridge Druce’, Zones 4–8), provides continuous summer color. It travels by root and by seed, so be careful to weed out seedlings that jump too far.
Bishop’s hat (Epimedium X versicolor, Zones 5–9) spreads more modestly, with deep roots that gradually expand. Its heart-shaped evergreen leaves rise on wiry stems, and dainty yellow flowers top the foliage in spring.
Some variegated perennials can also form luminous carpets in dry shade. Growing from deep-rooting corms, winter-blooming magenta Cyclamen coum (Zones 5–9) flaunts handsome leaves marbled with silver. Its corms increase in size over time, and ripe seedpods explode, sending out seeds, which germinate easily. Variegated archangel (Lamiastrum galeobdolon ‘Variegatum’, syn. Galeobdolon luteum, Zones 4–8) is also beautifully marked with silver and grows from creeping rhizomes. It displays spikes of lemon-yellow flowers in summer.