San Diego County's biome is California Chaparral. From mini-mountainous peaks and down eleven west-ward draining watersheds, our county boasts of micro-climates and plant groupings with unique characteristics. Some micro-climates you may encounter or live in are: Oak Savanna, Sycamore and Willow Riparian Corridors, Chaparral, Coastal Sage, Mountains, and Desert.
Depending on where your home or land is sited within these micro-climates will determine which varieties will thrive best. Adaptive traits drought tolerant plants sometimes exhibit are: waxy or glossy leaves, water storing leaves or tissues, serrated leaf margins, silver or light reflecting color, and the ability to solar track or reduce UV overexposure.
Explore the Water Conservation Garden near Cuyamaca College to see an excellent exhibit showcasing water wise and drought tolerant plants.
A young Chilopsis growing in a storm water harvesting basin in East County San Diego. ©ecologyartisans.com
An impressive small to large tree, desert willow provides very distinct seasonal interest. During winter, this deciduous California native sheds all of its leaves and can appear to look quite dead. But, fear not! This hardy and water thrifty plant is merely resting for spring. Beautiful pink-to-lavender-to-magenta flowers (they are similar in appearance to penstemons) hang alongside green, narrow (hence "linearis") leaves.
Height: 15 to 40 feet
Spread: 6 to 27 feet USDA
Zones: 5 to 10
Links: Wildflower.org or Las Pilitas
AKA: Desert willow, Flowering willow, Willow-leaved catalpa, Willowleaf catalpa, Bow willow, Flor de mimbre, Mimbre
Vitus agnus-castus growing in a parking lot planter. photo cc KM
Hailing from the Mediterranean region (which shares a very similar climate to ours: long, hot summers; short, wet winters), Chaste tree is a great insectary attractant, especially for butterflies. This evergreen shrub impresses with delicious scented foliage and attractive lavender flowers. Full or partial shade. Thrips can sometimes attack this plant and over watering leads to root rot (once established infrequent deep waterings are recommended). This tree was once used medicinally in ancient times to regulate female hormones.
Agave parryi nearing full size. photo cc Dallas Krentzel
Succulents are usually a top choice for water starved regions with mild winters. Agaves can range from soft bodied shade lovers to leathery Mad-Max survivors. Artichoke agave aligns with the survivors. Sharp, slightly curved spines edge the margins of these silvery-blue leaves. A gorgeous contrast of deep red spines with a prominent apex spine on each leaf will quickly teach a gardener respect. The dense rosette of leaves looks akin to an artichoke thistle. Slow growing and of reasonable mature size, you can periodically forget to water these and they will be no worse for wear.
Goodding's Verbena in bloom. photo cc Katja Schulz
Perfect for that landscape zone at your home that is rocky and gets baked by the sun. While drought tolerant, this verbena appreciates some moisture to show off its pink and purple flowers. Low growing with a three foot spread, Goodding's verbena is a nice addition. Well draining soils are a must, as is full sun. Can be short lived even though it's a perennial, but readily reseeds. Great butterfly attractant.
Blooming sundrops. photo cc Ray Mathews
Another low-growing subshrub perennial, sundrops displays soft yellow flowers that can be coaxed into re-blooming with some irrigation during the growing season. If you're planting a rock garden, then this plant is perfect for you! While deciduous, sundrops will remain evergreen in frost-free zones of your landscape. Pruning is best done in early spring by pinching the tips after flowering to increase the shrubbiness. Use well draining soils.
Nitrogen fixing native, this lupine brings seasonal beauty to native landscapes. photo cc The Marmot
Native California annual, arroyo lupine emerges every spring to grace hillsides with soft palmate leaves and purple-blue and violet blooms. Disturbed areas are one of its favorite habits, readily reseeding, this native helps rebuild soil with its deep and extensive root system. Its tolerance for heavy soils and extra water makes it more robust in garden landscape settings whereas its cousins can be notoriously difficult to cultivate. Leguminous, this plant helps fix nitrogen in the soil if its partner bacteria is present (use native soil from healthy, existing areas where it's growing to help inoculate your garden).
Prime time bluebells edging a walk. photo cc Patrick Standish
This herbaceous annuals puts off enjoyable blue flowers during its springtime bloom. Originating in sandy, desert edge environs, this is a great Zone 4/5 plant or any area where you are cultivating California chaparral natives. Grows well with "tiny campanulas, annual viper bugloss or for contrast with shorter calendulas."
Yellow catkins of Prosopis chilensis grafted to Prospsis juliflora. photo cc Dick Culbert
Mesquites are hardwood trees that withstand brittle environments if they get a foothold and enjoy periodic soakings. This thornless grafted mesquite adds welcome dappled shade to hot patios, sunward sides of structures, and private gathering areas. Tall, stout and arching, this graft blends the benefits of a Southwest native rootstock and South American thornless species. Full sun and limited ground cover competition is ideal for this tree.
Close up of rips and marginal spines of Fence Post Cactus. photo cc Forest and Kim Starr
As long as heat and sun and low-moisture soil are in right balance, this cactus can be left alone. Used for perimeter and home fencing in the southwest and Mexico when planted in tight spacing. Spines are easy to navigate and handle with gloves. Propagate these columnar cactuses by placing calloused cut ends directly into the soil.
Bush anemone flowers in full bloom. A great native hedge plant. photo cc The Marmot
Wishing to create a California native hedge that can stay attractive throughout the season? Bush anemone will please and attract pollinators with its 2-3 white flowers and soft yellow stamen. Low rainfall areas like San Diego should supplement with irrigation. Keep fertilization low, as will all natives, or leggy-ness and stunted lifespan can occur. Height: 5-15 feet Spread: 1-5 feet USDA Zones: 8 to 10 Links: Moosa Creek Nursery or Las Pilitas
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