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Ask the Master Gardener: Think beyond cacti, succulents for landscaping plants that use less water

Question: I don’t care for cacti and succulents. What other landscape plants use little water?
Answer: Actually many plants other than those usual suspects have adapted to get by with less water or to store water for later growth.  A good place to start would be the UC Davis Arboretum All-Stars: http://arboretum. ucdavis.edu/plant_search.aspx  
According to this website, “The horticultural staff of the UC Davis Arboretum have identified 100 tough, reliable plants that have been tested in the Arboretum, are easy to grow, don’t need a lot of water, have few problems with pests or diseases, and have outstanding qualities in the garden.”
But of course, the All-Stars aren’t the only drought-tolerant plants to be found. There are certain plant characteristics that suggest a plant may tolerate water stress. Look for silvery or fuzzy foliage, which are often clues that a plant has lower water requirements. The presence of fine hairs on the leaves of some plants like silver sage (Salvia argentea) is an adaptation that traps moisture at the leaf surface.
Michael V. Mickelbart, Dept of Horticulture & Landscape Architecture at Purdue University, writes, “Leaf hairs (called trichomes) appear as grey or white pubescence and reflect light and reduce water loss. While we still don’t fully understand how trichomes affect plant water loss, leaves that are covered with these small hairs typically lose less water than those that do not.”
The thickening of a leaf or needle with a wax coating is another indication of drought tolerance. Waxes are thought to prevent water loss and reflect light, which keeps leaf temperature from becoming too hot.
Since large leaf areas have more surface area from which water can be lost, drought-tolerant plants will often have small leaves (or in the case of conifers — needles). Another way trees reduce leaf area is by having deeper sinuses. Sinuses are the indentations between leaf lobes.
Trees and other shrubs with large leaves that are cut with deep sinuses are more tolerant of dry conditions because their total leaf area is reduced by the sinuses. And some plants roll or curl their leaves when stressed for water, thereby reducing the leaf surface exposed to sunlight and consequently the water loss.
Then there are the plants that flower only in winter or spring, going dormant during the long, hot summer months. Think of the beautiful spring bulbs, like tulips, daffodils, and irises. They grow, flower and die before the dry season ever arrives.
Some plants have a deep, expansive root system that can find and capture water, even in small quantities. They tend to do better in hot climates than plants with shallow root structures.
Note: Almost all landscape plants don’t become drought tolerant until they are established. They require consistent moisture for about one year after planting.
Do some research but don’t assume “California native” is synonymous with “drought tolerance.”
There are many lists of drought-tolerant plants online. Besides the Arboretum All-Stars, check out Sunset’s list of “Top 50 Water-Wise Plants”: http://www.sunset.com/garden/flowers-plants/water-wise-plants. And it’s not all succulents and cacti!