I bet many of you are thinking ‘what the heck is glaucous, anyway?’
Well, according to Webster, glaucous means:
1. of a pale yellow-green color, or of a light bluish-gray or bluish-white color
2. having a powdery or waxy coating that gives a frosted appearance and tends to rub off
And here’s a fun-fact from Wikipedia: the first recorded use of glaucous as the name of a color was in the year 1671.
So, while this word has been around for hundreds of years, it still eludes many gardeners.
I wonder if it’s partly because it’s such an unattractive sounding word (sounding like something stuck in the throat.)
Or maybe it’s because the definitions are a little all over the place: is it pale yellow-green? Or light bluish-gray? Or, bluish-white? Frosty? Powdery? Hmmm…
Whatever the reason, one of my favorite color combos of all time is glaucous and purple/maroon/burgundy, all nestled together.
There are a few reasons why this combination works so well.
One reason is that all of those subtle colors contained in a glaucous leaf makes for some pretty cool combo-opportunities when combined with purple. Temperature cool, as well as visually cool.
Take a look at the color wheel, and you’ll notice there’s a line drawn down the middle that separates the cooler and warmer colors.
Notice that all the colors in this glaucous-purple combo just so happen to land on the ‘cooler’ side of the wheel: violet thru yellow-green.
In contrast, the other side of the wheel has warmer colors: red, orange, and yellow (Click here for some examples of warming up the garden).
Another reason why this glaucous-purple combo is so lovely to look at is that they’re analogous to one another.
What’s analogous mean?
Simply put, it means if you choose colors that are next to one another on the color wheel (usually in groups of three to six) the effect will be calming and pleasing to the eye.
That’s because analogous colors have components of each within them, therefore allowing the combination to blend seamlessly with one another.
Take a look at the color wheel again, and you’ll see that the yellow-green/bluish-gray glaucous colors are neighbors with maroon/burgundy/purple. The result is a cooling, refreshing, pleasing, harmonious combination.
And, thanks to the glaucous foliage (with its blue, green, and gray undertones) these combinations tend to be a little out-of-the-ordinary, adding that much-needed ‘oomph’ to your garden bed.
Here are a few of my favorite examples that include foliage, edibles, succulents, and flowers, too!
Matilija Poppies (romneya coulteri)
I don’t know which I love more, the color of that foliage or the giant, fried-egg flower?
Honeywort (cerinthe major purpurascens “Blue Honeywort”)
I grow these from seed every spring (thanks to Annie’s Annuals) and am always rewarded with freebie-seedlings that surprise me again in the fall.
St. John’s Wort ‘Sunburst’ (hypericum ‘Sunburst’)
My favorite St. John’s Wort variety, not only because of its fabulous blue-green foliage (that helps those yellow flowers to really POP) but because it’s also rabbit and deer-resistant.
Red-Leaf Rose (rosa glauca)
While I do see tinges of red in the leaves, I’d rather call this the Blue-Leaf Rose for the glaucous shades that are also there. Either way, it’s a most unusual rose to add to the garden. This beauty would look fantastic planted against a dark green shrub, like the viburnum below. To read more about this unique variety, click here.
Fringe Flower (loropetalum chinense var. rubrum ‘Razzleberri’)
There’s a ton of loropetalum varieties out there, but the tried-and-true ‘Razzleberri’ tends to be the most reliable for me, as well as having those desirable glaucous colors in certain months of the year. Whenever possible, I like to place something steely blue nearby, like the ‘Globosa’ spruce and ‘Elija Blue’ fescue, below.
Gopher Spurge (euphorbia charasias sub. wulfenii)
I love euphorbias for so many reasons (click here to see why!), but the blue-green foliage of e. wulfenii is one of my favorites. It can re-seed when happy, so make sure to remove the dead flowers to prevent that from happening. Or not – depending on how much you love them, too! In the second photo, you can see how great it looks when paired with the blue-purple colors of the purple sage (salvia purpurea).
Hibiscus ‘Perfect Storm’
Don’t even get me started on why I love this plant so much. It’s a hardy (as in HARDY!) hibiscus, way more resistant to drought than the tag indicates, gorgeous leaves that change color throughout the seasons, lime green flower-pods, and the biggest, most amazing flowers you’ve ever seen. Don’t believe me? Click here and scroll down to see proof!)
The blue-greens in the foliage are especially stunning with the nearby blue Monch’s aster flowers.
Blue Rye Grass (leymus arenarius ‘Glaucus’) & Honeybush (melianthus ‘Antonow’s Blue’)
Succulents seem to epitomize just how gorgeous a glaucous leaf can be. There are way too many varieties to list, but some of my favorites are below: graptopetalum, beschorneria, echeveria imbricata, and agave parryi.
Of course, I have to include hostas as having the quintessential glaucous foliage. Just like the succulents above, there are too many varieties to list here, but below are a few of my favorites: ‘Hadspen Blue,’ ‘Great Expectations’ and ‘Mouse Ears.’
A trip to Freeland and Sabrina Tanner’s always-fabulous garden perfectly demonstrates that edibles, too, can provide amazing glaucous colors in the garden. Examples here are Tuscan Kale, cabbage varieties, blueberries, and artichokes.
Phew! I realize I’ve left off a million more glaucous plants, but there’s only so much time in a day.
What are some of your favorites?