Turning a Barren Slope into a Colorful Garden Oasis

From Moonscape to Lemonade Garden

“If you’re given lemons, you make lemonade,” says landscape designer Maile Arnold of the “lemon of a backyard” she transformed into the beautiful garden pictured here. Steep slopes and hard soil made this Glen Ellen, California site a gardening challenge. Construction cuts had left a hot, dry bank of white volcanic soil so desolate it looked like a moonscape.

Creating Drama at the Base

Arnold knew new plantings would take time to cover the bare slope, so she drew attention away from it by creating drama at its base. She built a dry‑stone wall 6 feet out from the slope’s base, filled it with fertile soil, and planted it with long‑blooming perennials in vibrant purples and reds to echo the house’s colorful Mexican interior.

Testing Plants on the Upper Slope

On the upper slope, Arnold experimented with a range of plants to see which would tolerate heat and poor soil. The proven winners? Lavender, Mexican bush sage, Myoporum parvifolium ‘Putah Creek’, red‑leaf Japanese barberry, rosemary, and smoke tree. She planted figs and persimmon trees at the bottom of the slope so their canopies will eventually provide shade and screening.

Informal Beds and Low‑Maintenance Paths

Throughout the rest of the backyard, Arnold planted informal, irregularly shaped beds with billowy perennials. Each bed contains an accent plant—such as a tree or rose—and is surrounded by grass and gravel paths made from decomposed granite.

Two years after planting, the garden is awash with colorful blooms from spring through fall. “The hot, bright, difficult place is now soft and beautiful,” says Arnold.

DESIGN: Maile Arnold, Sebastopol, CA (707/823-1373).

Color Makers for Hot, Dry Gardens

Blooming Plants

• CROWN‑PINK (Lychnis coronaria). White‑foliage perennial or annual to 2½ ft tall with magenta flowers. All Sunset zones.
• DAYLILY (Hemerocallis hybrids). Deciduous or evergreen perennials with grassy leaves and flowers in many colors; 1‑6 ft tall. All zones.
• ‘FIREBIRD’ PENSTEMON. Bushy, upright perennial 2‑4 ft tall with red tubular flowers. All zones (annual in cold climates).
• ‘IRENE’ TRAILING ROSEMARY. Trailing evergreen bush 1 ft tall by 6 ft wide with violet‑blue flowers. Zones 4‑24.
• MEXICAN BUSH SAGE (Salvia leucantha). Shrubby perennial to 4 ft tall with velvety purple flower spikes.
• MYOPORUM PARVIFOLIUM ‘PUTAH CREEK’. Ground cover to 3 in tall with bright green leaves and white flowers in summer. Zones 8‑9, 12‑16, 18‑24.
• ‘PROVENCE’ LAVENDER. Upright, rounded evergreen shrub 2‑3 ft tall with highly fragrant flowers. Zones 4‑24.
• ROSES. ‘Altissimo’, red climber; ‘Joseph’s Coat’, multicolored climber. All zones.
• SALVIA GREGGII. Evergreen shrub to 4 ft tall with small flowers from spring through fall. Many colors. Zones 8‑24.
• SANTA BARBARA DAISY. Spreading evergreen perennial ground cover, 1 ft tall by 4‑6 ft across. White or pinkish daisies all year in mild climates. Reseeds. Zones: 8, 9, 12‑24.
• ‘SISKIYOU PINK’ GAURA. Long‑blooming perennial to 3½ ft tall with rose‑pink flowers. All zones.
• TEUCRIUM FRUTICANS ‘AZUREUM’. Evergreen shrub 4 ft tall by 5 ft wide with dark blue flowers and gray leaves. Zones 4‑24.
• VERBENA BONARIENSIS. Airy, branching perennial with 3‑ to 6‑ft‑tall flowering stems topped with purple flowers. Reseeds. Zones 8‑24.
• V. RIGIDA. Spreading perennial 1‑1½ ft tall by 3‑4 ft wide with rough, dark green leaves. Lilac to purple‑blue flowers summer through fall. All zones.

Foliage Plants

• RED‑LEAF JAPANESE BARBERRY (Berberis thunbergii ‘Atropurpurea’). Graceful, deciduous shrub 4‑6 ft tall with bronzy red to purplish foliage all summer. All zones.
• SMOKE TREE (Cotinus coggygria). Deciduous shrub or tree to 25 ft tall with green leaves that turn red in fall and smokelike flowers. ‘Royal Purple’ has purple leaves. All zones.