The Perennial Matchmaker

Features such as flower forms, leaf shapes, and plant habits all play a part in interesting pairings, but color is what draws many of us to perennial combinations. There’s a lot of science behind how we perceive color and a good deal of theory behind the art of combining colors to create specific effects. Ultimately, color is a very subjective thing; if you find two hues pleasing together, it doesn’t matter whether art or science agrees, because you’re the one who’ll be enjoying the plants you combine. But if you’re new to creating combinations or are at a loss for ideas, classic color themes may provide a useful starting point. Here are some basic concepts to consider when you’re working with color-based combinations.

One simple way to approach the subject is by using a color wheel: a visual representation of the colors of the rainbow arranged in a circle.

An artist’s color wheel includes three primary colors—red, yellow, and blue—plus the secondary colors you get by mixing equal amounts of two primaries: orange between red and yellow, green between yellow and blue, and violet (purple) between blue and red. Tucked among those are tertiary or intermediate colors, which include a primary and a secondary color: blue-green, for example, or yellow-orange, or red-violet. Adding white to these hues produces tints (also called pastels, if there’s a good deal of white); adding black to hues gives shades; and adding gray (some black and some white) creates tones.

If you decide to delve deeper into color theory, you’ll find that there are a number of other ways to explain the ways colors can be described and combined to make other colors. (Computer monitors, for instance, use red, green, and blue as the three primary colors, while printing processes use cyan, magenta, and yellow.) It’s all very interesting, but keep in mind that working with color in the garden is much different than on a computer screen or on paper because we’re looking at blooms and leaves against all kinds of backgrounds and in many different kinds of light, depending on the time of day and the weather. And the plants themselves are continually varying slightly or dramatically in color, depending on their growing conditions and the age of their flowers and foliage. However, we can still use the basic terms and ideas to approach plant pairings and groupings.

Go monochrome. If you’re particularly drawn to one color, that can be a good starting point for a combination or even a whole garden. Technically, no pairing or planting is ever truly monochrome: Even if all the flowers are tints and shades of blue, for instance, there are greens from the various leaves and stems and probably yellows and whites from markings or parts within the blue flowers. Still, the intention is obvious enough that we can think of it as a “blue garden.”

Working with one color sounds like an easy way to go, and it usually is if you’re working with just a few perennials. You simply need to remember to add contrast with different flower forms, leaf shades, plant habits, and so on, since their colors are so similar, or the combination won’t offer much variety to hold your attention. This variety becomes increasingly important as you expand from a pairing to a grouping to a whole garden. Once you try your first monochrome garden, you’ll appreciate how much thought goes into creating something that appears to be so simple!

Stick with similarities. Combinations based on colors that are close to each other on the color wheel (also known as analogous colors) can actually be easier than monochrome combos, because there’s already some variety in the hues. One way to think of similar hues is to divide them into “warm” or “hot” colors (reds, oranges, and yellows) and “cool” colors (greens, blues, and purples). Pastels and whites also tend to look good together, creating a very soft, delicate effect. Deep shades paired with black or near-black work well, too, producing a rich, powerful impression. When you work with these sorts of similarities—hot colors, cool colors, pastels, or saturated shades—you’re practically guaranteed to come up with pleasing color combinations.

Add drama with contrast. Don’t feel like playing it safe? Have fun pairing colors that are directly or almost directly across from each other on the color wheel, such as yellow with violet, blue with orange, and red with chartreuse (yellow-green). (These are called complementary and near-complementary colors.) Or try a triadic scheme, using three colors that are spaced at equal intervals around the color wheel, such as red with yellow and blue or red-orange with blue-violet and chartreuse. Dark and light contrasts, such as black with white or red with silver, are also quite striking.

These sorts of groupings tend to be vibrant and attention grabbing: very useful in a border that’s seen from a distance. Up close, the effect of high-contrast combinations depends on the viewer: Some people find them cheery and playful, while others may consider them gaudy and chaotic. Again, you’re the one living with the plants, so if you enjoy a flamboyant garden, then go for it! If the idea appeals to you but you’re not confident with trying high-contrast combinations in high-visibility spots, save them for a side yard or a backyard border and stick with more restrained color schemes out front.

Once you start looking at perennials with an eye toward creating combinations, you’ll notice that their most obvious colors aren’t the only hues they have to offer. Considering their more subtle touches of color can inspire interesting partnerships that lead to truly sophisticated combinations. Focusing on these sorts of subtleties in your combinations is a wonderful way to make even a very small garden worthy of close attention. Taking fine details into account also works well in plantings that you can admire up close: by a door, along a path, or next to your deck, patio, or favorite garden bench, for instance.

Bloom attributes. Petals usually provide the overall color, but if you look closely, you’ll notice color in other flower features, as well. The reproductive parts in the center, for instance, are generally yellow, green, bronze, or brown to near-black. It’s also quite common for petals to include several tints or shades of one color, or even multiple colors, creating markings such as stripes or bands or a contrasting center “eye.”

Flowers include structures called sepals, which cover the petals while the flower is developing. They’re often hidden by the petals when the blooms open, but sometimes they peek through not-quite-overlapping petals or are evident when you look at the flower from the side, adding green or other colors to the blossom.

Foliage features. Leaves can be just as valuable as flowers for providing color: even more so, in fact, because leaves are around for most or all of the growing season (sometimes even all year), while blooms are much more fleeting. In the greens alone, there are striking tints, shades, and tones, from green so dark that it’s practically black to cool blue-greens and gray-greens and brilliant yellow-greens. Other pigments can add varying amounts of red and purple to the green, creating moody maroon and rich burgundy, while hairs or waxy coatings on the leaves or air pockets below the surface can make green leaves appear gray, powder blue, or silver.

Like flowers, individual leaves can include multiple colors as well, from subtle shades of one color to distinctive spots, splashes, speckles, and stripes, or contrasting edges or centers. Many variegated leaves are green with white, cream, or yellow markings, but foliage can also show combinations of two or more other colors, such as yellow with red or gray with burgundy.

Additional interesting elements. Other places to look for colors that you can play off of in plant partnerships include buds, leaf and flower stems, fruits, seeds, and seed heads. It’s fair also game to consider colorful accessories, such as painted posts, bits of trellising, decorative pots, and other sorts of garden ornaments, as well as nearby features, such as paving, walls, fences, hedges, and arbors.

Understanding some of the basic facts and theories about color will help you figure out why certain combinations might or might not be pleasing to your eye. But when you actually put two plants next to each other, you’ll find that colors can appear and combine very differently in the garden than art and science may lead you to expect. Here are some tips to keep in mind when you’re working with specific colors in your combinations.

Rousing reds. By themselves, red flowers are bright and attention grabbing, but in the garden, they may get lost if they’re set against lots of green leaves. Adding white flowers and white-variegated and bright silver foliage adds more contrast, but the overall effect of a red, green, and white garden may be more suited for the Christmas season than a summer border. Reds with yellow flowers and leaves, and some orange, too, are equally festive but far better suited to the growing season.

The most interesting “red gardens” usually include maroon, burgundy, and purple foliage to add variety to red flowers and leaves. These foliage colors help to separate violet-reds, pinkish reds, and orange-reds, which may not look good right next to each other. It can be a real challenge to find enough red-flowered perennials to make a good show at any one time, so take advantage of annuals, bulbs, and shrubs with red flowers, leaves, stems, or fruits, too.

Tricky pinks. Adding white to red makes pink, but that simple formula hardly does justice to the wide range of pinks available in perennial flowers. Add a little white to pure red and you get a vibrant reddish pink; a lot of white produces a delicate pale pink. If you start with an orangey red, you get coral to salmon to peachy pink; a purplish or bluish red with white can produce hot pinks, fuchsias, or rosy pinks. Adding gray to red produces many more varieties of pink.

There are so many kinds of pink, and so many terms for the various tints, tones, and shades, that depending on written descriptions when you’re planning pink combinations can produce very disappointing results. You’ll combine two pinks that sound like they should look good together only to find that they’re just not quite right to your eye. To further complicate matters, some flowers hold their particular pink from start to finish, while others fade or deepen as they age or as weather conditions change. Seeing particular pink flowers in person—at a garden center, for instance, or in someone else’s garden—is the safest way to judge whether the pairing is pleasing to your eye.

Of course, pink flowers can combine beautifully with many other colors, especially when they’re similar in intensity: strong pinks with bright yellows, blues, and purples, for instance, and paler pinks with soft yellows and creams, baby blues, lavenders, and peaches. Pairing pinks with reds and oranges is a challenge, but it’s worth attempting if you enjoy adventurous combinations. (Adding deep purple or burgundy foliage to a pink-and-orange or pink-and-red combo may be all that’s needed to make the flowers look fine together.)

Joyful yellows. There’s certainly no shortage of yellow perennials for any time in the growing season. There are greenish yellows, clear yellows, and orangey yellows, from soft ivory to cream to bold, brassy gold: not just in flowers, but in foliage, as well. On petals, the primary yellow may lighten or darken from the outer tip to the attachment point, or it may appear with white or with other colors, such as red, orange, or green. Leaves may be a solid yellow or yellow with green, red, blue, silver, or white. Yellow leaves (often referred to as golden, or as chartreuse if they’re a greenish yellow) may hold the same color all through the growing season, develop a reddish or orange blush in cool weather, or turn green or whitish as they age.

With so many perennials in this category to choose from, yellow is a wonderful place to start for a pairing, grouping, or entire garden. Try bright yellow with rich red and orange flowers and dark foliage for a hot tropical look; cool it down with violets and blues; or team it with white for a cheery effect. Softer yellows are outstanding partners for baby blues, pale purples, light pinks, and peachy flowers, and with silvery, gray, or blue leaves. Or go for a “yellow garden,” based on a range of tints and shades plus greens from the leaves and perhaps a dash of blue, silver, and/or peach.

Active oranges. Though few gardeners would claim orange as their favorite flower color, it can be part of some really interesting and exciting combinations. Bright orange flowers create exuberant groupings with similarly intense yellows, scarlet, and reds, and they look terrific with purple and/or chartreuse foliage. Or use somewhat deeper shades of orange, amber, and rust with reds, violets, and purples, along with dark foliage, to create a sunset-to-twilight combo or border.

Pairing orange with pink may sound awful at first, but it can work; in fact, it can look great! Try putting some purple foliage between these colors, or use the tan seed heads of ornamental grasses instead. Coppery leaves, like those of New Zealand sedges (Carex) and some heucheras (Heuchera), include touches of both pink and orange, so they, too, can make good blenders.

If you’re not comfortable with vivid oranges, consider trying tints instead. Soothing colors, like salmon, apricot, peach, and buff, are lovely with light yellows, pinks, blues, and lavenders in flowers and with greens, blues, grays, and silver in leaves.

Agreeable greens. It’s easy to overlook the value of green in plant pairings. It’s so common in leaves and stems that we often forget it is there, but it can play a big part in the overall appearance of a combination or planting, particularly when and where flowers are scarce, such as in winter and spring, or in shady areas in summer and fall.

Like other hues, green comes in all sorts of interesting variations, from bright yellow-greens to cool blue-greens, with shades so deep that they’re practically black, as well as lighter tints and tones of pale green and gray-greens. With some attention to choosing contrasting shapes and textures, it’s possible to make memorable combinations working only within the greens.

Bright and deep greens make a crisp contrast with white, silver, pastels, red, and scarlet, and they make vibrant companions for yellows and oranges. Rich purples and blues get lost against darker greens but look brilliant with yellow-greens (as do reds and oranges). Light greens, blue-greens, and gray-greens blend gently with white, silvers, and pastels.

Enchanting blues. There’s something special about blue flowers, so it’s not surprising that so many of us are drawn to creating combinations with them. While there aren’t many true blue perennials, there are plenty that are on the purple-blue side, and when you consider all the various tints, shades, and tones, there’s no lack of great candidates for blue duos and trios, as well as entire beds and borders.

Because blues are so close to greens, it’s very easy for them to get lost against a lot of green leaves. Keeping them where you can see them at close range is one way to handle that; setting them against a light background, such as a pale fence or wall, is another. Light-colored companions—such as white and yellow flowers and silver, yellow, and white-variegated leaves—also help to make blue flowers into true standouts. Many blue flowers already include a bit of white and/or yellow in the middle, so pairing them with a white- or yellow-petaled partner and then adding white-and-green, yellow-and-green, or solid yellow foliage is a simple formula for a stunning combination.

Blues with reds can be interestingly attention grabbing or unpleasantly jarring, depending on your taste; either way, they’re a strong pairing, and just a touch of one with a lot of the other can go a long way.

Blues are very pretty with pinks, especially if you match their intensity (cobalt blue with fuchsia pink, for instance, or baby blue with pale pink). A border based on blues, blue-purples, and pinks with touches of white, gray, and silver is a classic look and easy to design. Or expand to a wider pastel palette of light blues and lavenders with soft yellows, pinks, and peachy flowers combined with accents of blue leaves and cream-variegated foliage. These paler colors are easy to see, so they’ll work well even in a border that you view at some distance.

Vibrant purples and violets. Though different gardeners use different terms for the basic colors in this range, we all know these mixes of blue and red when we see them. In many ways, the clear purples and violets act like blues, blending into green leaves and needing lighter flowers, foliage, or backgrounds to help them get the attention they deserve.

Bright purples and violets create exuberant combinations with equally vivid yellow, red, and orange flowers and look amazing with golden to chartreuse foliage. They’re great with pinks, too; in fact, it’s not unusual for flowers that we call purple or pink, such as cultivars of hardy geraniums (Geranium) and phlox (Phlox), to include a good amount of both of those colors. Rich reddish purples and violets are absolutely exquisite with deeper shades of gold, orange, red, and other twilight colors. Or set yourself to the challenge of a border based on shades of blues, purples, violets, and red. Adding white or gray to purple and violet gives us lovely varieties of lilac, lavender, and orchid, and these make charming partners for white and pastel selections.

Radiant whites. Oh, the many possibilities for combinations with white! It’s hard to beat the crisp, clean effect of a simple white-and-green or white-and-blue pairing, and a white-and-yellow combo is radiant even in shade or twilight. Bright white also adds zip to a border based primarily on pastels. It’s outstanding with silvers and creates a strong contrast with reds and purples in both foliage and flowers.

Besides pure white, there are plenty of perennial flowers that are basically white but have touches of green, blue, purple, pink, yellow, or other colors appearing in features such as bands, streaks, stripes, edges, and centers or mixed into the white itself (often most notably in cool weather). It’s easy to play off of these additional colors when choosing a companion: a yellow-leaved partner for a white-and-yellow iris, for example.

A white garden or moon garden is always a tempting project, and there’s no lack of great candidates to work with besides white and almost-white blooms, such as green leaves that are variegated with white or cream. (Cream in leaves tends to be white in hot weather and strong sun and more yellow in cool weather, but it’s wonderful either way.) Silver, gray, and blue leaves are also superb with white.

The one drawback to white flowers is that they can look terrible once they’re past their peak, so remove the aging blooms as they turn brown. Or keep your whites away from high-traffic spots; you won’t notice the discoloration nearly so much from a distance.

On the Dark Side

When it comes to foliage, “purple” is a very different color than it is in flowers. Chlorophyll is what gives leaves a green appearance, but it’s not the only pigment they contain: Anthocyanins (reds and blues) can mask the green to a greater or lesser extent. Because the green is still there, you generally don’t get a clear color, like the purple of an iris or aster. Instead, it’s usually a shade anywhere from a wine red (burgundy) to reddish brown (maroon) to a chocolate brown to near-black. Features on top of or within the leaves can create grayed purples—as on the younger leaves of ‘Purple Emperor’ sedum (Sedum)—or silvery purples—as on some heuchera (Heuchera) cultivars, such as ‘Blackberry Ice’. With all of this variation, it’s often easier to think of foliage plants in this group as “dark” rather than “purple.”

Dark foliage looks great mixed with “hot” colors, such as oranges, golds, yellows, and reds, adding a touch of sophistication that can save the grouping from appearing garish or gaudy. Paired with white, yellow, or pink flowers or yellow or silver foliage, dark leaves create a strong contrast. Dark foliage is often a terrific companion for flowers that include dark centers, spots, bands, or other markings, such as many daylilies (Hemerocallis) and true lilies (Lilium). And it creates sultry duos with equally dark blooms, as in this pairing of ‘Erica’ Culver’s root (Veronicastrum virginicum) and ‘Queen of Night’ tulip.

The color variations in dark foliage aren’t very obvious in a planting you see from a distance, but up close, leaves that lean toward brown can look very different from those that are more of a reddish purple. For that reason, it’s a good idea to see the leaves for yourself before you settle on a specific combination. Also, keep in mind that the intensity of leaf darkness can vary by site and season. Purples, reds, and browns tend to be strongest in full sun and on new growth, particularly in cool weather; if they get too much shade, or if the weather gets hot, they may appear a purplish or brownish green.

IN THE PINK. Soft pinks are beautiful with blues, as in the combination of ‘Bevan’s Variety’ bigroot geranium (Geranium macrorrhizum) with ‘Ultramarine’ forget-me-not (Myosotis sylvatica) (left). They also make a great match with dark foliage, as on ‘Dark Towers’ penstemon (Penstemon), shown with the pods of ‘Cramers’ Plum’ love-in-a-mist (Nigella damascena) (right).

YELLOW BEDFELLOWS. Pinks and purples—like those of Joe-Pye weeds (Eupatorium) and ironweeds (Vernonia)—pair prettily with yellow-flowered partners, such as ‘Lemon Queen’ perennial sunflower (Helianthus); solid yellow foliage, like that of Briant Rubidor weigela (Weigela florida ‘Olympiade’); and yellow-variegated leaves, like those of ‘Oehme’ palm sedge (Carex muskingumensis).

USING BLUES. Mixing tints and shades of purple and blue, as with dark ‘Caradonna’ perennial salvia (Salvia nemorosa) and paler ‘Walker’s Low’ catmint (Nepeta), tends to create a soft, hazy effect. Working in some strong shapes, such as the very vertical stems of just-in-bud Japanese iris (Iris ensata), is one way to add some drama; a contrasting background—in this case, ‘Royal Purple’ smokebush (Cotinus coggygria)—is another option.