Ask any 4-year-old what color leaves are, and they’ll confidently proclaim, “Green!” And green leaves are just fine, for the most part. We expect gardens to be basically green, from the verdant lawn to the tops of the trees (at least during the growing season). When it comes to plants, that glowing, chlorophyll-derived green implies life and health.
But one can have too much of a good thing. That’s why our landscaping includes plants with leaves that are a soft silver (that sounds much better than “gray”). No, I don’t want an entire yard full of them, but as accent plants, silvery leaves can make quite the impression.
There are many shades of gray, ranging from pewter to silver, with some tinted blue or green (described as “glaucous”).
While they’re beautiful in their own right, they look even better when paired with companions that will set off their striking color.
When it comes to flowers, I favor brilliant colors such as raspberry pink and flaming orange. Yet, if every plant in my border sported such intense hues, the effect would be blinding. That’s where a soft, dove gray interlude saves my eyesight. I use ground-covering perennials such as Missouri evening primroses, snow-in-summer, and lamb’s ears to tone it down a bit. Gray goes with everything.
Other Colorado-friendly perennials with gray-toned leaves include various Salvias, Artemisia sp., Greek and Serbian Yarrows, Sea Holly (which even has silver-blue flowers), sunroses (Helianthemum sp.), Russian sage, and catmint. And there are dozens more.
A number of ornamental grasses have gray to gray-blue foliage, such as Blue Oat Grass (below). Consider pairing them with similar-but-green cultivars for contrast. Festuca sp. is another, low-growing grass that is even more silvery; it’s perfect for edging.
Gray leaves also act as a neutral foil to container gardens. Dusty Miller is an old stand-by, but when the flowers are annuals, Santolina, Partridge Feather (Tanacetum), and other less-hardy perennials should also be considered.
Now that fall has arrived, silvery foliage plays the same role, only this time the costars are brilliant red maples and sumac, or flaming-orange little bluestem grasses. Our back neighbors have a maple that was planted directly behind our row of buffaloberries (Shepherdia). While I’m apprehensive that it will shade our sun-loving shrubs as it grows, right now the juxtaposition of crimson and silver is breathtaking.
Plants with silver foliage seem to fit Colorado’s intense sunlight and dry climate. Gray is reflective, and these plants thrive while our sunny days and thin air combine to overwhelm and burn more delicate leaves. That same reflective property also cools the leaves by several degrees.
Many gray-leafed plants are also fuzzy. Those little hairs offer some protection from drying winds and reduce transpiration, making these plants a good choice for an exposed hot, dry location. This is why many xeric species are dressed in silver.
Silver leaves also tend to be small and thick, rather than flat and wide. The reduced surface area is another adaptation to a dry climate. However there are exceptions, such as the floppy leaves of Silver Sage (Salvia argentea). Perhaps the thick pelt on the leaves is enough to maintain its xeric qualities.
Those gray, fuzzy leaves tend to be less palatable to herbivores, although nothing is deer or rabbit proof. As an added benefit, many insects are “programmed” to look for green, not gray.
In general, plants with silver foliage do best in full sun. They have the same chlorophyll as green plants, but it’s hidden by that fuzz, or a waxy cuticle, or other modifications of the leaf surface.
I may not want my great-grandmothers silver tea set (I’d hate to have to polish it), but silver plants don’t tarnish. Go ahead and fill your garden.
Photos, from top: Artemisia ‘Sea Foam’, Agave, Snow-in-Summer (Cerastium sp.), Sea Holly (Eryngium bourgatii), Sunroses (Helianthemum sp.), Blue Oat Grass (Helictotrichon sempervirens) x 2, with Japanese Blood Grass, Dusty Miller, Partridge Feather (Tanacetum), buffaloberry (Shepherdia), yarrow (Achillea sp.), Silver Sage (Salvia argentea).