One of the most useful colors in any garden is silver. Aside from white, no other color produces such a strikingly pale neutral that coordinates with virtually everything. Silver defines boundaries and balances color. It helps anchor a garden through strong contrast and visual buoyancy. It can even sit quietly in the background and let everything else shine.
Excluding metal objects, when we say “silver” in gardening terms we mean living foliage with a silvery bloom or cast. The color isn’t metallic, obviously. “Silver” foliage is closer to gray, powder blue, sea-glass green or pistachio, often with white fuzz. A few flowers can also pass as silver. All are valuable to the gardener for their high-contrast properties. In both very low and very strong light, these cultivars often reflect a silvery or pale countenance, hence the term “silver”.
Most silver plants are native to hot, dry climates. That’s because they’ve evolved silky hairs or a light color to deflect heat. Some of the best silvers in the plant kingdom belong to succulent agaves and cacti. But Pennsylvania is not the Southwest! We won’t be discussing these desert flora, since the most silvery aren’t hardy in zone 6.
Succulents however, also come in miniature silver versions that can stand in for their big cousins in rock gardens and containers. I won’t spend much time on succulents either; they deserve their own article. But I couldn’t resist including photos of several entries in a silver foliage and container competition I visited years ago. Stunning!
Containers aside, growing silver plants in wet summers and getting them to thrive is a challenge no matter which cultivars you choose. Let’s explore the most reliable.
It’s very important to give these plants full sun and excellent drainage. (Exceptions are a few silvers for shade like painted ferns, lamium and brunnera.) Most will not survive otherwise. Crushed stone or pea gravel mulch helps deter stem rot and fungal diseases.
Without further ado, in no particular order:
Wormwood or Mugwort
If you’ve heard of wormwood, southern wormwood, mugwort, or its Latin name artemisia, you might know this plant by its association with the alcoholic spirit absinthe. Absinthe is made from Artemisia absinthium, a species native to Europe and North Africa. In addition to absinthe the liquor industry uses absinthium extract as a bittering agent for a range of other liquors. (Don’t try this at home!)
Out of 470 species, several artemisias are supposedly hardy in our area: Silver Mound, Powis Castle, Silver King, Silver Queen, Valerie Finnis and Silver Brocade. I find that’s only partly true.
You’ve surely seen or grown Silver Mound or Powis Castle. Silver Mound looks like a fluffy, mint-green pouf of foliage. Powis Castle is taller with finely divided foliage. I find both to be short-lived.
As much as I adore them, they rarely survive beyond two years. Silver Mound splays open by midsummer, looking bedraggled and sad. A wet winter or even a bad storm can easily do them in. For that reason I don’t recommend either one. Silver Brocade is similar to Silver Mound.
These are xeric plants after all, happiest in a drier climate with low humidity. You can’t blame them for sulking here!
On the other hand, North American nativars Valerie Finnis, Silver King and Silver Queen (also called prairie sage) have been reliable for me. At 18″ to 24″ tall they contribute substantial presence to a mixed border. They will self-seed and spread via runners if neglected, so manage them proactively or use a physical barrier. I once grew Valerie Finnis and forgot about it. By season’s end I was composting it by the wheelbarrow load. So, I get it– artemisia is not for everyone.
Why would anyone put up with this rampant thug at all?
Because Valerie Finnis, for instance, is a billowy pale aqua-turquoise, stays disease-free all season and provides unparalleled contrast. It’s the perfect mid-border filler. A nice-sized patch makes a terrific foil for so many plants! It’s excellent in cut flower arrangements too.
Then again, I admit I’m partial to silver plants no matter how badly they behave, so that’s probably why I do it.
Lamb’s Ear
This old-fashioned favorite is indispensible for a true silvery look. Lambs ear (Stachys byzantina) comes in several cultivars; the two most popular are Silver Carpet and Helen von Stein.
Silver Carpet – This is the more silvery of the two. Some people like the leaves but not the flowers; if you’re one of them, just cut the spikes off as they start to form. I happen to love the flowers, pointing skyward like fistfuls of pale arrows. When backlit, a clump in bloom is a sight to behold. The bees think so, too!
Silver Carpet is easy to keep within bounds with one cut-back immediately after bloom and another at season’s end. Use gravel mulch and well-drained soil for the healthiest plants. If the foliage starts looking ragged, cut it back hard and it will regrow afresh.
Helen von Stein – Helen is “flowerless” with luxuriant felty foliage that looks quilted and edge-stitched. Pistachio in color, the leaves take on a silver cast in strong light. Helen is a fast spreader; be prepared to give some away or ruthlessly compost the extras. Lovely for low borders where a lush, neat appearance is important all summer.
Dusty Millers
Dusty Miller (Silver Ragwort Senecio/ Jacobaea) is a catch-all term for several half-hardy perennials with lacy silver-gray foliage. We typically treat them as annuals in zone 6. We’re all familiar with them.
To make a design statement with it in the garden though, you need a lot of these plants, so it can get pricey to mass them. But dusty miller is unsurpassed for adding zip and contrast to containers and borders.
Senecio
Here’s an exciting introduction for containers with real “wow” power: Senecio Angel Wings. It’s so silver it’s nearly white. This annual is best appreciated in a pot or up close where it will stay tidy all summer, putting on very little growth. It’s a novelty plant to be sure, rather unreal in its appearance. Just look at that foliage!
Silver Ground Covers
If you want a good silvery ground cover, try Cheddar Pinks or Snow-in-Summer. Both make neat, small-leaved mats of soft gray-green. Some people also have good luck with brunnera and lamium; I don’t.
Cheddar Pinks
Cheddar pinks are members of the dianthus family. Dianthus Bath’s Pink is getting hard to find at nurseries because newer hybrids are displacing it. But Bath’s has absolutely superb foliage for rock gardens, walls, raised beds and low borders. I love its strong vanilla-clove scent wafting through the spring air. When the flowers finish just give it a haircut once, and voila! You’ll have a lovely ground cover the rest of the season.
Other dianthus varieties can be substituted but may not be very silvery, with varying degrees of hardiness. Bath’s has the best foliage hands down for use as a groundcover. I haven’t had much luck with other dianthus varieties the last few years.
A word of caution…Bath’s Pink must have excellent drainage and lean slightly alkaline soil or it will languish. Don’t even try it in rich soil. (It loves pea gravel; a raised bed or berm helps with drainage.)
Snow-in-Summer
I happen to think snow-in-summer (cerastium tomentosum) is an outstanding groundcover for sun-baked areas. A quick haircut after spring flowering will keep it neat the rest of the season, right into cold weather. In mild winters it remains mostly evergreen year-round.
Here it’s paired with golden barberry, blue fescue (another great silver), annuals and dwarf conifers. It will spread modestly and “flow” around rocks, too. As with dianthus, give it full sun and good drainage.
Other Silver Foliage Options
- Licorice plant helichrysum petiolare — an annual petite vine, wonderful for pots or tumbling over walls
- Silverheels Horehound Marrubium rotundifolium — a low mounding groundcover with silvery edges and undersides. Prefers it dry. (Regular horehound is nice too, but not silver).
- Miscanthus Morning Light – variegated Chinese Silver Grass (and others; many grasses turn buff to silvery in winter). Exceptionally lovely when the plumes are backlit in low light.
- Blue Fescue grass – small but mighty! A terrific silver choice.
- Rose campion – an airy biennial with hot pink or white flowers. Its habit is similar to lambs ears, but lankier. Trim occasionally.
- Japanese Painted Fern – several variegated choices for shade
Lavender? Depends
Lavender is popular in Europe as a contrasting color for knot gardens and borders. But with our harsh winters and humid summers I find most lavenders challenging to sustain. Lavender foliage can be dark gray and unsightly in early spring, so I hesitate to recommend it for silver effects.
If you want to grow lavender for its silver value, consider Ellagance Snow [sic?] a white-flowered cultivar. It will read as “silver” much better than a purple-hued lavender. Of course, purple lavender looks absolutely stunning as a companion to any silver plant!
If you want to pair the two, try Phenomenal, a new (purple) hybrid bred to tolerate extreme conditions better than most, with the white.
Three Silver-Flowered Options
Bluestar
Also called Amsonia. A. hubrictii is a two-for-one cultivar. The flowers are pale blue silvery stars, almost steely. I use it to echo larger silver plants. In fall, bluestar’s foliage turns a rich golden yellow. Mass this bluestar close together for maximum impact, as the individual blooms are small. The foliage will form soft, billowing clouds.
Incidently, A. hubrictii is not the same as the hybrid Blue Ice, also lovely; that amsonia has a bluer flower with a different look.
Globe Thistle
Echinops Star Frost bears flowers that resemble steely orbs, a useful, fun form in the garden. (Being in the midst of the pandemic, I realize it also resembles sars-cov-2, the virus that causes covid– but let’s stay positive!) Wonderful to behold on a frosty morning, like silver lollipops.
Rattlesnake Master
An Eryngium cultivar named Rattlesnake Master is a prairie native with spiky silver balls on freely branching stems. It was named by Native Americans who used it to treat snakebite. You can’t beat this plant for architectural structure. It’s a tall native that can be slow to establish, so consider accordingly.
By all means if you can grow other eryngiums (sea holly) feel free to do so — they are among the most silvery plants there are! Unfortunately I’ve had terrible luck with them so I no longer try.
I’m sure there are other splendid silvers out there that I’m missing…add your thoughts in the comments. There are loads of variegated cultivars, blue or gray succulents, conifers and shrubs. But this list should at least get you started!
Not Recommended
The below choices are often touted for their silvery foliage. Because they’ve been problematic for me, I can’t recommend them. I sometimes grow them, but admittedly not well. By all means, use them if you wish.
- Russian Sage – the largest varieties get floppy and unwieldy; new hybrids can lack substance or foliage isn’t silvery enough. Hopefully there will be improved cultivars coming out soon.
- English and French lavenders – hard to sustain in wet winters; foliage can get ratty and discolored. Try overwintering these in pots in an unheated, frost-free garage.
- Eryngium (Sea Holly) – hard to sustain in wet conditions
- Lamium – temperamental; foliage can turn unsightly or go dormant after bloom
- Showy Milkweed – ungainly and awkward; foliage gets ratty. May die out in wet conditions
- Siberian bugloss Jack Frost – lovely but not reliably hardy
- Wooly thyme – hard to sustain; too petite to make an impact
- Yarrow – gray-green foliage gets ratty; needs frequent trims to stay presentable
Non-living silvers
You don’t have to limit silver to just plants. By introducing metallic, light gray or highly polished elements like driftwood, granite, sculpture, pavers and so on, you can easily create a sense of calm. Silver’s neutrality never detracts or clashes. This means you can use a lot of it without being visually overwhelmed, the way you would with a strong color in large amounts. Silver unifies, defines, and adds sparkle.
Even reflections off a water feature or fountain can count as silver.
Some people like to add lots of baubles, wind chimes, flags, statues and so on. I prefer a garden to be as natural and uncluttered as possible with just one or two elegant, substantial focal points. The result is far more restful and restorative (to me, anyway).
Although cool colors compliment silver best, it can also tone down hot reds and yellows, balancing their heat. You can’t go wrong.
Silver in Winter
Finally, not enough of us consider our gardens “out of season.” A winter garden can be very beautiful in its own right, and it’s not that hard to have one if you remember to plan for it.
How might you use introduce silver in winter? With less plant material to work with, it can be as simple as taking advantage of sunlight where reflections occur naturally. Depending on the time of day, sometimes you even get gold.
Some possibilities:
- Position a few architectural plants so they catch the winter sunset; hydrangeas and grasses are wonderful for this.
- Select trees with shiny, pale or papery bark like sycamore, apple, birch and cherry. Their reflections “read” as silver.
- Consider adding a heated water source for its reflective qualities, whether it’s a koi pond, a birdbath or fountain.
- Add interesting forms such as corkscrew hazel (Harry’s Walking Stick) whose twisting branches turn silvery in hoarfrost
- Incorporate at least one conifer to enjoy it enrobed in icicles.
- Plant a pussy willow for its silvery catkins in early spring.
All will provide extra sparkle and definition.
By placing the right plant or element in the right place, invite silver into your garden for a lovely garden experience all year long.
