The state of California has been parched, baked and seared under the latest in a string of droughts of historic proportions. Under a gubernatorial mandate to reduce water use by 36% the time has never been more right to wean off the green and bring our desert landscapes into line for a sustainable future. Upon first encounter the vast, open seemingly lifeless expanses of desert can oft times seem a harsh and foreboding place. The lush and verdant landscapes of the valley’s communities offer a sense of comfort and familiarity for first time visitors and longtime residents alike but belie the arid nature of the area in which we live. The American standard landscape of turf and foundation plantings of ubiquitous shrubs uses 75-90% more water than a water efficient landscape and misses out on the opportunity to establish or re-enforce a sense of place and a blending of our neighborhoods with our unique natural surroundings. We are fortunate to live in a land that offers the natural diversity of palms to pines in such close proximity, but judging from our landscapes we often seem to forget about the desert in between.
The lack of many landscapes to celebrate our arid heritage is even more astonishing given the incredible diversity of unique and remarkable plant species indigenous to arid and semi-arid regions that are available for use. Plants such as cacti, agaves, ocotillos, aloes, euphorbias, alluaudias, yuccas, dasylirions and nolinas offer an almost endless variety of size, form, texture and bold accents from which to choose. Let’s take a look at what makes up an effective and water efficient desert landscape.
What is Desert Landscaping
Most people think of cactus and sand or gravel.
These can be key components but it can be so much more with a blend of plants adapted to arid climates and hardscape elements, rock, cobble, and DG.
Like the desert itself there should be a spatial component, informal spacing and separation of plants or groupings of plants looks most natural. Many of the varied accent plants suitable for desert landscaping also lend themselves to interesting formal treatments.
Irrigation supplied by drip or low flow systems with an eye towards water conservation.
It should evoke a regional sense, a southwest flair. Carpets of turf and hedgerows of privet could just as easily be in the Midwest or back East.
Use of native plants helps to establish a sense of place.
What are the Advantages?
Plants from arid climates are adapted to growing in typically well-draining impoverished soils, making the chore of amending the soil unnecessary. In fact some plants, members of the pea family most notably, can actually enrich the soil by fixing atmospheric nitrogen with the help of bacteria living on their roots.
Plants accustomed to hot, arid climates will be less stressed by the weather and therefore, hopefully healthier and less prone to disease and insect problems.
Use of native plants will help support local populations of birds and insects. Even just a few native plants in each landscape can help bridge the ever widening gap between open spaces. eighteen species of local butterflies have been recorded visiting desert lavender, a fragrant member of the sage family. Resident and migratory hummingbirds love chuparosa. Queen and Monarch butterflies use desert milkweed as a host plant. Cactus wrens will nest in cholla branches.
Drip irrigation promotes less weed growth since water is delivered to single spots instead of broadcast sprayed.
Properly selected and sited trees can reduce cooling costs by 10 to 30% .
Shade canopies from trees and shrubs can lessen the urban heat island effect of our paved world.
Established arid adapted plants will weather the storm when the irrigation clock malfunctions in the middle of summer and fails to deliver water for a week or more.
Elimination or reduction of areas of turf reduces the amount of resources used to maintain it.
What Makes it Attractive
The incredible variety of succulents and accent plants available for use – cacti, euphorbias, agaves, aloes, yuccas, nolinas, dasylirions, ocotillos.
Rock in the landscape, from boulders to cobble to DG. Our native soil doesn’t bring a lot to the plate as far as bringing color to the landscape. Adding a layer of DG can help bring a finished look to a landscape.
Rocks can fill voids and balance out a landscape where the temptation is to plant more plants.
Wide variety of materials available from local rock yards.
The right plants in the right setting give it the right feel.
Water-efficient doesn’t mean colorless. Seasonal splashes of color from plants like penstemons, brittlebush, chuparosa, Texas rangers, palo verdes and smoke trees enliven the landscape. Some plants provide almost year round color in our mild low desert climate; Baja fairy duster, angelita daisy, desert marigold and Baja ruellia seem to always be in bloom. And don’t forget about the spectacular displays put on by many of the cacti!
How do you Maintain
Along with planting drought tolerant species the most critical step in reducing water use in the landscape is managing the irrigation schedule, changing it with the seasons and shutting it down when significant rain events occur.
Keep an eye on the plants, if something looks dry check the bubbler, if a large area looks dry check the irrigation clock.
Right plants in the right spots should lead to minimal pruning. Southwest plant material looks better allowed to grow naturally. When needed, selective pruning should be practiced rather than shearing. Eliminating the weekly shearing reduces time spent on maintenance, reduces the amount of green waste produced and allows for greater flower production.
Deadheading or removing spent flowers can help tidy up and encourage repeat blooming but remember many plants such as brittlebush produce seeds that are relished by wildlife. Allowing the plants to go to seed increases the likelihood of wildlife spending time in your landscape.
Some older plants that have become sparse with age can be rejuvenated with a hard pruning at the right time of year.
Many desert trees want to grow as big shrubs, they will need to be lifted over time if an overhead canopy is desired. In high wind areas, canopies may need to be opened up to lessen the wind sail effect and allow air to pass through.
Do not top trees, topping destroys the natural shape of the tree and promotes weak branching that may become a liability down the road.
Suspend the use of herbicides and pesticides, few if any insecticides are target specific and kill as many or more beneficial insects as pests. Systemics are passed not only to the bug sucking on the plant but to the hummingbird drinking the nectar and the bee gathering the pollen. If you have a plant that has such a problem that can’t be remedied without chemicals maybe you can do without that plant.
Plan on bubblers or emitters near the drip line of trees at maturity where the feeder roots will be to encourage a wide spreading root system.
Water Use and Why Does it Matter
Theoretically water is a renewable resource but demand is exceeding supply.
It shouldn’t really be a question of whether we can afford our current rate of water use financially, but rather viewed from a moral perspective. The ongoing drought in California has made reduced water use a mandate.
The Coachella Valley was blessed with an underground aquifer that has supported the greening of the desert but it can’t last forever.
Recharge basins were developed to replenish underground stores but can’t keep up with withdrawal rates.
Continued wasteful practices roll the dice on the future of the Valley.
70 – 80% of domestic water use goes to the landscape. It’s an area where real savings can be made.
Install low flow irrigation or retrofit existing systems.
If removing turf that is inter-planted with trees remember to provide sufficient irrigation for the trees when redoing the irrigation system.
Water early morning to minimize water loss due to evaporation.
If planning a landscape with plants with varying water needs group or zone them together so they can be irrigated separately. When everything is on one system you are always watering for the least drought tolerant plant.
WUCOLS – Water Use Classification Of Landscape Species is available on line to help identify water needs of plants. Look for most recent version WUCOLS IV. The Coachella Valley is Zone 6. The plants are rated by high, medium, low and very low water use.
Smart irrigation – controllers linked to satellite feeds sending daily adjustment according to current conditions.
CVWD website offers examples of seasonal irrigation schedules. Check with your water agency to see if they are offering incentives for switching to Smart controllers or reducing the amount of turf in your landscape.
Any Pitfalls to Avoid
Save water and headaches from lost plant material by planting in season, late Sept. through March. Planting during the hot season can be done but will take diligence with watering and some plants will struggle with getting established.
Consider exposure orientation, for most desert plants an eastern exposure is heaven, a western – not so much. For those really hot exposures like west walls and reflection off light colored surfaces use plants that can handle it.
In desert landscaping it’s all about getting water to the plants roots – make sure that bubblers are upslope from the plant and that water is indeed getting to the plant and not channeling off somewhere else. It’s amazing how a subtle shift in contour can deflect the water away. Make temporary basins if needed.
Basic landscaping 101 – know the ultimate size of the plant, especially when it comes to the relationship between spines, thorns and walkways. Planting a one gallon or five gallon agave or desert spoon too close to the path will result in body or plant mutilation or removal down the road.
If using an organic mulch that stays wet keep it off the stem or trunk.
Do not plant too low, dig the hole just as deep as the root ball so it won’t settle. Digging deep and adding amendments to the hole are no longer recommended.
Low Water Use Plants
In addition to the native plants already noted, the following is a list of plants classified as low water use by WUCOLS (Water Use Classification Of Landscape Species) plus some plants deemed low water use at The Living Desert. All succulents are considered low water use with an occasional exception.
This is not an all-inclusive list as there are certainly many plants yet to be evaluated but does offer an ever expanding selection of plants that have had at least some level of expertise directed at gauging their water use requirements.
Look for the newest version, WUCOLS IV Plant List, on-line.
The low desert is in Zone 6. The plants are rated high, medium, low an very low water use.
Many of these plants can be purchased in The Palo Verde Garden Shop at The Living Desert. If you don’t see what you’re looking for contact the nursery manager and she will try to locate them for you. If homeowners and landscapers supply the demand at the nurseries the growers will do their best to fill that demand.
|Abutilon palmeri||Indian mallow||shrub|
|Senegalia (Acacia) berlandieri||Guajillo||tree/shrub|
|Acacia craspeodcarpa||Leatherleaf acacia||tree/shrub|
|Acacia pendula||Weeping acacia||tree|
|Vachellia (Acacia) pennatula||Fern-leaf acacia||tree|
|Acacia redolens||Prostrate acacia||ground cover|
|Acacia salicina||Willow acacia||tree|
|Acacia stenophylla||Shoestring acacia||tree|
|Acalypha monstachya||Rasberry Fuzzies||perennial|
|Adenium obesum||Desert Rose||succulent|
|Agave spp.||Agave||succulent accent|
|Ambrosia deltoidea||Triangle-leaf bursage||shrub|
|Anisacanthus thurberi||Desert honeysuckle||shrub|
|Anisacanthus wrightii||Desert honeysuckle||shrub|
|Antigonon leptopus||Coral vine||vine|
|Baccharis sarothroides (male only)||Desert broom||shrub|
|Baccharis Starn||Starn baccharis||shrub|
|Baccharis x Centennial||Centennial baccharis||shrub|
|Baileya mulitradiata||Desert marigold||perennial|
|Bauhinia congesta||Cow-foot orchid tree||tree/shrub|
|Berlandiera lyrata||Chocolate flower||perennial|
|Bignonia capreolata||Cross vine||vine|
|Bouteloua curtipendula||Sideoats grama||grass|
|Bouteloua gracilis||Blue grama||grass|
|Buddleja marrubiifolia||Butterfly bush||shrub|
|Bursera spp.||Elephat trees||tree/shrub|
|Caesalpinea pulcherrima||Red bird of paradise||shrub|
|Calliandra californica||Baja fairy duster||shrub|
|Calliandra eriophylla||Pink fairy duster||shrub|
|Celtis pallida||Desert hackberry||shrub|
|Celtis reticulata||Western hackberry||tree|
|Ceratonia siliqua||Carob tree||tree|
|Cordia boissieri||Texas olive||large shrub|
|Cordia parvifolia||Little-leaf cordia||shrub|
|Coursetia glandulosa||Baby bonnets||large shrub|
|Cupressus arizonica||Arizonia cypress||tree|
|Dalbergia sissoo||Indian rosewood||tree|
|Dalea frutescens||Black dalea||shrub|
|Dalea greggii||Trailing dalea||ground cover|
|Dalea pulchra||Silver smokebush||shrub|
|Dasylirion spp.||Desert spoon||accent shrub|
|Ebenopsis ebano||Texas ebony||tree/shrub|
|Eremophila spp.||Emu bush||shrub|
|Ericameria larcifolia||Turpentine broom||shrub|
|Euphorbia xantii||Shrubby euphorbia||shrub succulent|
|Eysenhardtia orthocarpa||Sonoran kidneywood||tree/shrub|
|Eysenhardtia texana||Texas kidneywood||tree/shrub|
|Fallugia paradoxa||Apache plume||shrub|
|Forestiera neomexicana||Desert olive||shrub|
|Fouquieria spp.||Ocotillo||shrub succulent|
|Furcraea spp.||Furcraea||accent succulent|
|Galvezia juncea||Baja bush snapdragon||shrub|
|Glandularia (Verbena) goooddingii||Gooding’s verbena||perennial|
|Gossypium harknessii||San Marcos hisbiscus||shrub|
|Gossypium thurberi||Thurber’s cotton||shrub|
|Haematoxylon brasiletto||Brasil||small tree|
|Havardia mexicana||Mexican ebony||tree|
|Hesperaloe parviflora||Red yucca||accent succulent|
|Hesperocyucca whipplei||Our Lord’s candle||succulent accent|
|Jatorpha cinerea||Lomboy||shrub succulent|
|Juniperus californica||California juniper||shrub|
|Leucophyllum spp.||Texas Rangers||shrub|
|Macfadyena unguis-cati||Cat claw vine||vine|
|Mariosousa (Acacia) willardiana||Palo blanco||tree|
|Mascagnia macroptera||Yellow orchid vine||vine|
|Maytenus phyllanthoides||Mangle dulce||shrub|
|Melampodium leucanthum||Blackfoot daisy||perennial|
|Oenothera caespitosa||Tufted evening primrose||perennial|
|Pachycormus discolor||Elephant tree||tree succulent|
|Parkinsonia spp.||Palo verde||tree|
|Pedilanthus macrocarpus||Slipper plant||shrub succulent|
|Poliomintha maderensis||Mexican oregano||shrub|
|Portulacaria afra||Elephant food||shrub succulent|
|Psilostrophe cooperi||Paper flower||perennial/shrub|
|Psilostrophe tagetina||Paper flower||perennial/shrub|
|Quercus fusiformus||Escarpment live oak||tree|
|Rhus lanceolata||Prairie flameleaf sumac||shrub|
|Rhus ovata||Sugar bush||shrub|
|Ruellia californica||Rama parda||shrub|
|Ruellia peninsularis||Baja ruellia||shrub|
|Ruellia x brittoniana||Dwarf ruellia||subshrub|
|Salvia apiana||White sage||shrub|
|Salvia brandeegei||Santa Rosa Island sage||shrub|
|Salvia californica||Baja California sage||shrub|
|Senna artemisioides||Feathery senna||shrub|
|Senna phyllodenia||Silvery senna||shrub|
|Solanum hindsianum||Baja nightshade||shrub|
|Sophora secundiflora||Texas mountain laurel||shrub|
|Tecoma stans||Yellow bells||large shrub|
|Tetraneuris acaulis||Angelita daisy||perennial|
|Vachellia (Acacia) farnesiana||Sweet acacia||tree|
|Vauquelinia californica||Arizona rosewood||shrub|
|Vauquelinea corymbosa||Narrow leaf rosewood||shrub|
|Vitex agnus-castus||Chaste tree||tree/shrub|
|X Chitalpa tashkentensis||Chitalpa||tree|
|Yucca spp.||Yucca||succulent accent|
|Wedelia acapulcensis||Devil’s River sunflower||shrub|