Leaf color is either silver or gray with no easily discernable green color.
Most gardeners’ acquaintance with veronicas is with the Veronica spicatas, ‘Red Fox’, ‘Icicle’, and ‘Sunny Border Blue’; the tall, spiky red, white and blue medium and high water-use veronicas. But consider the low water-use option, V. incana. Deadhead to prolong the blooms and water deeply once a month, once established in well-drained soil. The gray-green leaves should be a give-away by now as to its water requirements.
Wagons Ho! Rugged, ragged and windblown -- a true picture of the western and southwestern landscape. If you have a skeleton of a steer's head, now is the time to use it, along with that wagon wheel. Sometimes referred to as the western sage.
Big sagebrush is a coarse, many-branched, aromatic, pale-grey shrub with yellow flowers and light silvery-grey foliage. It flowers in late summer to early fall. The leaves are wedge-shaped with three lobes.
Chamisa or rabbitbrush is a medium tall shrub with blue-green stems that produce clusters of golden yellow flowers from September throughout fall, very showy in the landscape. Matted hairs on thin leaves cast a silvery appearance. Native throughout the southwest, in warmer climates it is evergreen. The official name has been changed to Ericamera nauseosa, but is still referred to as Chrysothamnus (meaning golden bush). Seeds prolifically -- is a good pass-along plant to friends, neighbors, relatives and passersby.
Shadscale lives in alkaline caliche soil in most of its native range throughout the Southwest and has a high tolerance of saline or sodic soils. Given improved soil conditions, it will grow larger. Do not improve the soil to insure it keeps its neat, compact shape. Shadscale blooms yellow flowers in early summer which mature into seed heads. Its silver-gray leaves are semi-evergreen.
Big Bend silverleaf is the most cold hardy of the Leucophyllums and has wintered over in Amarillo, Zone 7, for 5 years so far. Possibly cold hardy to Zone 6. It is hard to beat a more attractive summer blooming shrub for small xeric spaces. After summer rainfalls, Big Bend silverleaf, native to the Big Bend National Park area, becomes covered in silver blue flowers that twinkle like jewels among its silvery gray leaves. Hard to find, it's worth searching for.
Low water-use non-native hybrid shrub (Artemisia arborescens x Artemisia absinthium) from Europe and Asia. Vigorous grower, do not overwater. Coldy hardy to Zone 6. Ever-silver with elegant finely cut leaves. 'Powis Castle' is named for Powis Castle in Wales. Rarely flowers.
For more information and a list a gray and silver leaved plants, read Fifty Shades of Gray, my most viewed page.
Purple or desert sage prefers leaner, quick draining soils. It is said to grow 2-3 feet tall and deeply branched with silver gray foliage and a profusion of violet bluish flowers atop spikes in late spring and summer. Low water-use, but does better with once a month irrigation. One of the finest flowers of the desert, it is the sage of Riders of the Purple Sage, by Zane Grey. Grows throughout the Great Basin Desert.
Winterfat, formerly Ceratoides lanata, is a drought and heat tolerant that normally is found in poor, alkaline soils throughout the Southwest in grasslands and scrublands. Winterfat is a low rounded woody shrub with pale blue green to gray leaves. The distinctive characteristic is the long wooly seed stalk it puts up in the summer. Towards winter, the stalk appears to be covered with wool.
Lavender cotton, or gray santolina is a low mounding woody subshrub that should live on the lean side. Not that it won't overgrow if fed. It will maintain its compact shape in poorer soils without amending or fertilizing. Small silver gray leaves cover the shrub. Tiny yellow button flowers appear in summer. Evergreen, the santolinas are native to the Mediterranean area. Aromatic and edible, it's leaves were used as a flavoring in broths, sauces and grain dishes. Low water-use.
Grayleaf cotoneaster is a wonderful low growing shrub for the xeric garden. Evergreen or semi-evergreen in colder winters, it provides good winter interest, along with the other seasons. Small oval shaped silver/gray leaves cover the many arching branches. Tiny white flowers appear in late spring followed by red berries in late fall and winter. Low water use once established.
Artemisia versicolor 'Sea Foam' is mostly grown for its gray foliage. To keep it's desired compact shape, cut off flower stalks after blooming, which is its only maintenance. Soft, rubber-like feel to its short, clustered, needle-like appearance on short 1 inch wide columns. It gives the impression of a coral bed in your rock garden. Not invasive. 2004 Plant Select Plant.
A good drought tolerant ground cover for use in a border, in a xeristrip or a rock garden. Evergreen grayish green leaves with fine hairs (tomentose). Will grow too tall and gangling in too rich and moist a soil. Some areas of the country have noted Cerastium tomentosum to be invasive, but I have not seen those tendencies here. A good substitute for the annual alyssium. Cerastium tomentosum var. columnae is a commonly available variety.
Heucheras are native to the North American continent and make wonderful foliage and flower plants for your woodland border. Grown mostly for its interesting, evergreen foliage, coral bells will continue to flower on mature plants if kept deadheaded into the summer. Although the native heucheras are great in themselves, there are hundreds of hybrid cultivars to choose from.
Salvia argentea is a first class drought tolerant biennial to add texture to your xeristrip. Light gray green tomentose (hairy) foliage adds contrast against accent rocks. This biennial will flower the second year, but I could do without the sticky, and somewhat unsightly stalk whose white flowers open in succession and quickly turn brown. Cutting off the stalks only encourages the plant to send up more sticky stalks. The leaves of the plant may appear to mimic Lamb’s Ears, however, they are not tough and resilient, tears easily, and are shredded by hail.
Exciting drought tolerant groundcover! This gray-green leaved, evergreen groundcover adds quite a sparkle to any xeristrip or low water-use bed, border and rock garden. For prolonged summer blooms, water monthly during the growing season. Needs full exposure to sun and little water. Like's it's soil lean.
Delightfully fragrant with a sweet honeysuckle scent. A truly beautiful addition to any xeric bed or border.