These 3 silver-leaved plants are no-fail choices:
Acacia baileyana ‘Purpurea’ (Zones 9–10) is a lovely form of the Cootamundra wattle. Often considered a sunroom plant, it can be grown outside in warmer zones. The finely cut, fernlike foliage is blue-gray and the new shoots a deep purple—a wonderful contrast. The bright yellow flowers in spring are of secondary importance and lack the subtlety of the soft, delicate foliage. This is a good shrub to grow against a wall. Being light and leggy in habit, it is also very useful for providing height among the low-growing mounds of other gray-leaved plants, such as santolinas and lavenders.
Artemisia abrotanum (Zones 5–8), or wormwood, has been in cultivation for centuries, the original attraction being its aromatic leaves. One of the many herbaceous and woody artemisias, it is easy to grow and quickly makes a small upright shrub with gray-green downy leaves. Grayish flower buds appear ath the end of the stems in summer; there are best trimmed to prevent the shrub fwom opening up under the weight of the foliage when wet. In garden centers it is often found with the herbs rather than the shrubs.
Artemisia ‘Powis Castle’ (Zones 6–9) is a well-known and widely grown artemisia. The foliage is deeply cut and feathery, the habit, compact when young, becoming sprawling. It makes good groundcover, and when planted on top of a wall it cascades over the edge. This artemisia likes full sun and well-drained soil and dislikes wet, cold sites and heavy soil; on clay, add lots of pea gravel when planting to improve drainage.