by Carolyn Longstreth
Like many California homeowners, we have a steep slope on our property. When we bought the place in Northern California in 2006, I was baffled how to create a garden there. It’s an informal area but too steep for a cottage-style mix of roses and perennials. But the area turned out to be the sunniest part of our yard, despite its northwestern exposure and some large trees growing near the top. The gardener in me was drawn to it like a moth to a flame. We terraced the steepest spots and continued to ponder the challenge.
Eventually, I came up with the idea I now call my custom chaparral: We would plant the slope in a loose arrangement of low-growing, drought-tolerant woody shrubs– nothing taller than 6 feet. Between the shrubs, would be bunchgrasses, perennials and annuals. Because I love to grow natives and we did not plan to provide summer water, I decided to limit myself to California natives– not a major restriction, given the phenomenal diversity of our state’s indigenous flora. For me, using native species in the garden enhances the sense of place and, of course, makes the garden more attractive to birds, butterflies and other wildlife.
The slope garden is three to four years old now, but still getting established. Like a natural chaparral, the feeling is open, sunny and cheerful. But I have not tried to replicate the precise combination of shrubby species that grow on our sunny Marin hillsides. I planted several kinds of ceonothus and manzanitas, matilija poppy (one is plenty!), yellow bush lupine, silver-leaf lupine, Cleveland sage ( the cultivar, Winifred Gilman), California sagebrush, Oregon sunshine, California buckwheat, flowering gooseberry and a low-growing Fremontodendron (the cultivar Ken Taylor). In the shadier section, coffeeberry (cultivar Mound San Bruno), snowberry and other gooseberries are thriving.
These young shrubs give the otherwise unorganized space a bit of structure and a feeling of permanence. The gaps between them are filled with perennial buckwheats, foothill penstemon, monkeyflowers, California fuchsia, and bunchgrasses, such as Idaho fescue and purple needlegrass. In the shady area, native heucheras, hummingbird sage and California woodfern provide foliage contrast and flowers in season.
In April and May, the annual wildflowers create a joyful riot of color. The silky, bright yellow blossoms of coastal California poppies make a big statement, together with masses of tidytips. Quieter roles are taken by the lavender Chinese houses, the blue globe gilia and baby blue eyes, which thrive in partial shade on the mid-slope. When these have faded, clarkias and shade-tolerant large-flowered linanthus carry the display into June, July and even August.
This garden is not maintenance-free, partly because I mulch sparingly to leave room for the wildflowers. In winter, the chickweed, mustards and exotic grasses require weeding to prevent them from out-competing the annuals. Once this chore is finished, I just stand back and watch the young annuals surge to maturity. By late May or June, it’s time to weed again and cut the poppies to stimulate a second, less exuberant round of bloom. The shrubs and perennials appreciate occasional watering during summer, until they are fully established. By fall, the annual wildflowers have generally seeded themselves but periodically, I replant my favorites or try new species, always protecting the seeds and young plants from the birds with netting or floating row cover until they are a few inches high.
Like any garden, my custom chaparral is a work in progress. As it continues to evolve, I watch the changes, celebrate the successes, rethink the mistakes and plan for an even better slope garden next year.