By Greg Rubin
Article originally published in the newsletter of the San Diego Horticultural Society
Since starting my native landscape company in the early nineties, I have been approached by people who think that a native plant landscape means a cactus garden. The truth is, our California deserts actually have very few species of cacti. In fact, my old business card used to read “We’re Not Talking Cactus Here!” Not that there is anything wrong with cacti, but most of my landscapes tend to use evergreen, colorful shrubs and groundcovers that reflect the feel of Big Sur or Julian more than the desert. Then again, there are many folks who really like the open look of the southwest and want to capture that look at home. A truly authentic southwestern style landscape contains only a smattering of cacti and succulents; the backbone is still based on woody plants.
The plant palette for desert landscapes is surprisingly large.
Achieving the Southwest look is really about the setting. Our desert plant communities are adapted to extreme heat and meager precipitation. Each plant tends to be widely spaced from its neighbor, so it can have more room to gather moisture and nutrition. Because the density is so low, very little organic material is produced. The ground’s surface tends to consist of decomposed granite and small stones, often creating what is known as “desert pavement”. Boulder outcrops protrude from hills and low mounds, frequently accompanied by shrubs seeking shelter for their roots. The shrubs tend to be open, exhibiting dramatic shape and internal structure. Their leaves are usually small, though many are capable of dramatic seasonal flower shows following significant rains.
Unless drainage is perfect, desert landscapes prefer overhead watering. I always provide a completely separate irrigation system, as the desert, unlike its coastal counterparts, tends to receive as much moisture in the summertime (monsoons) as in the winter. This was evident on a recent trip I took during the summer of 2012. Especially heavy monsoonal rains had left the desert a verdant, sparkling green, despite temperatures regularly topping 110 degrees F. Because most of the winter’s moisture is blocked by coastal mountains, I rarely have to water my desert gardens between about November through May, watering two to three times per month during summer.
The plant palette for desert landscapes is surprisingly large. Although slow growing, the shrub that provides the greatest burst of green during the monsoon season is creosote bush (Larrea tridentata). This is a beautiful shrub with handsome structure and evergreen leaves. To me, the fragrance does not remind me of creosote, but rather a unique pungent sweetness that reminds me of the desert. One of the features of this wonderful shrub is its bright yellow flowers in spring.
There are many other desert shrubs to consider. When planting, remember that all of these plants need to be spaced far enough apart so that there are open areas between them when mature. Brittlebush (Encelia farinosa) is a mounding silver-gray shrub covered in bright yellow flowerheads in the spring. Its form and foliage provide an important contrast to upright, green desert shrubs. Apricot mallow (Sphae ralcea ambigua) is tremendously showy with its bright orange, cup-shaped flowers which are on display for many months. Apache plume (Fallugia paradoxa), from the rose family, is another favorite. This showy shrub is adorned with white flowers that transform into light pink plumes.
Salvia ‘Celestial Blue’ (Salvia pachyphylla x clevelandii) lends fragrance and produces deep purple flowers with bright pink bracts. These colors are complemented by the pink fairy duster (Calliandra eriophylla), which has tiny compound leaves and pink powder puff flowers.
Trees are important components to the desert landscape. I always recommend palo verde (Cercidium x “Desert Museum”), which has large yellow flowers on thornless branches and desert willow (Chilopsis linearis), which is covered in frilly, large, trumpet flowers and is available in many colors. Honey mesquite
(Prosopsis glandulosa) makes a beautiful shade tree with edible seed pods, though it is somewhat thorny. Desert olive (Forestiera pubescens) is a shrub/tree with gorgeous white bark, beautiful upright structure, and a benign nature.
Finally, use colorful perennials and succulents around the edges and near boulders. Consider penstemons like desert beardtongue (Penstemon palmeri) and showy penstemon (P. psuedospectabilis), goldenbush (Ericameria cuneatus) and succulents like various Dudleyas. Beargrass (Nolina sp.) can be used for spiky accents, and beavertail (Opuntia basilaris) works well as a rather benign but beautifully magenta flowered cactus.
Greg Rubin is a member of the CNPS San Diego Chapter. He is also the owner of California’s Own Native Landscape Design, started working with native plants back in 1985, while renovating his parent’s home in Chatsworth, CA. Although educated and subsequently employed in a successful engineering career, Greg maintained a fascination with natives based on this early experience. Soon, he was landscaping for friends and family on weekends and holidays. Demand continued to rise, and by 1993, Greg was able to start his successful and unusual landscaping business. Since that time, his company has designed over 600 native landscapes in San Diego County.