About the Author
Nancy J. Ondra is the author or coauthor of more than a dozen gardening books. She grows a wide variety of ornamental and edible plants at Hayefield, her 4-acre homestead in Bucks County, PA.
Excerpt. © Reprinted by permission. All rights reserved.
Achillea
classic summer perennials
Yarrows
Full sun; average to dry soil
Yarrows (Achillea) produce an abundance of tiny blooms clustered into flat- topped flower heads. Among the well-known yarrows with yellow flowers and silvery to gray-green foliage are 3- to 4-foot-tall 'Coronation Gold' and 'Gold Plate' fernleaf yarrow (A. filipendulina) and 18- to 24-inch-tall hybrids 'Moonshine' and Anthea ('Anblo'), all of which are hardy in Zones 3 to 9. Common yarrow (A. millefolium) and its hybrids, which usually flower at about 2 feet in height, expand the color range to include white, pinks, reds, and oranges, as well as yellows. They typically have very lacy bright green or graygreen leaves and are hardy in Zones 3 to 9.
Color Considerations
Yellow-flowered yarrows make striking partners for blue- to purple- flowering perennials, such as 'Brookside' and Rozanne ('Gerwat') hardy geraniums (Geranium), mountain bluet (Centaurea montana), and perennial salvias (Salvia). The bright yellows, including 'Coronation Gold' and 'Moonshine', also make eye-catching co-stars for equally intense reds and oranges, like those of Arkwright's campion (Lychnis x arkwrightii), butterfly weed (Asclepias tuberosa), 'Lucifer' crocosmia (Crocosmia), and Maltese cross (Lychnis chalcedonica), as well as other strong yellows, such as Jerusalem sage (Phlomis russeliana) and sundrops (Oenothera fruticosa), and crisp whites, like 'Becky' Shasta daisy (Leucanthemum x superbum). The bright yellows are excellent for echoing companions that have yellow- centered or -throated blooms, like those of Frikart's aster (Aster x frikartii) and many irises and daylilies (Hemerocallis).
When you're choosing companions for hybrids of common yarrow, be aware that it's common for their colors to fade as the flowers age. 'Cerise Queen' starts out bright pink and turns light pink, for instance, while 'Apricot Delight' goes from orangey pink to creamy pink, and 'Fireland' (also sold as 'Feuerland') turns from bright red to peachy yellow. Cut off the older blooms if you don't like their softer colors or leave them and select partners with the multicolor effect in mind.
Yarrows in the pink and softer yellow ranges, such as 'Saucy Seduction' and Anthea, look good with blues, purples, creams, and whites, as well as with silver, gray, and blue foliage. 'Inca Gold', 'Terracotta', 'Fanal' (also sold as 'The Beacon'), 'Paprika', and others in the oranges and reds are also interesting with blue leaves, as well as with yellow-variegated foliage and the buff-colored flower and seed heads of summer-blooming ornamental grasses, such as blue fescues (Festuca), blue oat grass (Helictotrichon sempervirens), and tufted hair grass (Deschampsia cespitosa).
A Perfect Match
I love making combinations with peachy and salmon colors, and 'Peachy Seduction' and 'Terracotta' yarrows are two of my go-to bloomers in this color range. They're beautiful with 'Black Adder' anise hyssop (Agastache), 'Walker's Low' catmint (Nepeta), and other purple-blues.
Shapes and Textures
The yarrows with yellow flowers and silvery leaves are usually clump formers, while common yarrow and its hybrids tend to spread out into broad patches. Most aren't particularly distinctive, shape-wise, except for individual clumps of fernleaf yarrow and its taller cultivars, such as 'Gold Plate', which are very upright and contrast well with mounded forms.
The deeply cut foliage gives yarrow plants a fine texture, but that's only obvious in spring and fall. Their primary shape-related feature is their umbel-form blooms (with many small flowers clustered into flat-topped heads). Repeat their strong presence with other perennials that have a similar shape, such as showy stonecrop (Sedum spectabile) and wild quinine (Parthenium integrifolium); with broad daisy-form flowers, like those of echinaceas (Echinacea) and rudbeckias (Rudbeckia); or with other large blooms, like those of daylilies and true lilies (Lilium).
For contrast, pair yarrows with small, simple flowers, like those of coreopsis (Coreopsis) or gaura (Gaura lindheimeri); with rounded clusters, like those of drumstick allium (Allium sphaerocephalon) and globe thistles (Echinops); with airy clusters, like those of catmints (Nepeta) and coral bells (Heuchera sanguinea); or with spiky blooms, like those of dense blazing star (Liatris spicata), penstemons (Penstemon), or perennial salvias (Salvia). Yarrow flowers look wonderful with the fine foliage textures of Mexican feather grass (Stipa tenuissima), New Zealand hair sedge (Carex comans), and other ornamental grasses.
Seasonal Features
Yarrows generally begin flowering in late spring in the South and early summer in northern gardens. Fernleaf yarrow and its selections are at their best through midsummer; then you can remove the dead flowering stems (cut them off close to the base of the plant, so the leaves will hide the stubs) or leave them in place to add structural interest in fall and winter. Other yarrows usually continue to produce new blooms through summer and even into early fall, especially if you regularly remove the finished flower stems. (This will also help to prevent an abundance of unwanted seedlings.)
Special Effects
If you're planning combinations for butterfly gardens, be sure to include pairings of yarrows with other butterfly favorites, such as butterfly weed (Asclepias tuberosa), pincushion flowers (Scabiosa), phlox (Phlox), and red valerian (Centranthus ruber).
Common yarrow and its hybrids, with their relatively loose growing habit, also look right at home in meadow gardens, interplanted with relatively low grasses, such as little bluestem (Schizachyrium scoparium) and prairie dropseed (Sporobolus heterolepis), and other meadowy perennials, such as butterfly weed and rudbeckias.
Yarrows are great in bouquets, too, so they're excellent companions for other long-lasting blooms, like those of coral bells (Heuchera sanguinea), lavenders (Lavandula), and purple coneflower (Echinacea purpurea).
Managing Your Yarrows
Yarrows (Achillea) may be short lived, especially in good soil, and usually benefit from being divided every other year. If you prefer to stick with lower-maintenance plants in your main perennial borders, consider keeping your yarrows--as well as other short-lived perennials, such as black-eyed Susan (Rudbeckia hirta), blanket flowers (Gaillardia), gaura (Gaura lindheimeri), and rose campion (Lychnis coronaria)--in a separate area. Interplant them with annuals and tender perennials that need to be replanted each spring anyway, and it won't be a big deal to divide or replace the yarrows at the same time.
Bloom Buddies
Marvelous Matches for Flowering Combos
Yarrows (Achillea) tend to grow best in soil that's on the dry and not- especially-fertile side. They can adapt to more regular watering and richer soil, though they tend to be sprawling there. Below are some other sun lovers that overlap with the peak early- to midsummer bloom period and make great companions for yarrows.
African lilies (Agapanthus)
Anise hyssops (Agastache)
Bee balms (Monarda)
Blackberry lily (Belamcanda chinensis)
Blazing stars (Liatris)
Blue flax (Linum perenne)
Butterfly weed (Asclepias tuberosa)
Catmints (Nepeta)
Coreopsis (Coreopsis)
Echinaceas (Echinacea)
Gaura (Gaura lindheimeri)
Globe thistles (Echinops)
Lavenders (Lavandula)
Marguerites (Anthemis)
Mountain bluet (Centaurea montana )
Mulleins (Verbascum)
Penstemons (Penstemon)
Perennial salvias (Salvia)
Red valerian (Centranthus ruber)
Rudbeckias (Rudbeckia)
Russian sages (Perovskia)
Speedwells (Veronica)
Summer phlox (Phlox paniculata)
Sundrops (Oenothera fruticosa)
Torch lilies (Kniphofia)
