ACHILLEA. Yarrow. Europe, Asia, N. America. Rugged perennial daisies, with finely cut, often aromatic leaves and flat-topped flower clusters. Ours are mostly spring and summer blooming. Full sun, well drained soil, moderate to little watering when established. Most are hardy to 0o and below.
clavenae (argentea). Silvery yarrow. A tidy mat of silver-grey, rather broadly cut leaves, providing pleasing color contrast in the border. It produces smallish heads of white flowers on 4-8" stems.
filipendulina ‘Coronation Gold’. Fernleaf yarrow. A widely spreading plant with finely cut grey leaves. Throughout the summer months it carries broad heads of brilliant yellow flowers on 2-3' stems.
Galaxy Series. This is a group of hybrids recently imported from Germany. The proud parents are reputed to be A. millefolium (pink and red flowered forms) and A. ‘Taygetea’. The plants most resemble A. millefolium vegetatively, making thick mats with pale to dark green, dissected leaves. Flowering stems are mostly around 2' tall, and freely produced in the warmer months. The flowering heads are quite large, like those of A.’Taygetea’, but unique in their colors: These range from garish scarlets and oranges to soft pink and buff shades. We are currently growing ‘Heidi’, with huge clusters of deep pink blossoms fading to pale pink; ‘Paprika’, with burnt-orange flowers; ‘Salmon Beauty’, with flowers colored pale salmon, fading creamy yellow; and ‘Debutante’, a seed strain spanning the full range of colors for this series.
x kellereri. This is one of my favorites of the group. It forms dense hummocks, up to perhaps 1' broad, with narrow, finely divided grey leaves. Clusters of unusually large, pure white flower heads are carried well above the foliage on 8-10" stems.
millefolium ‘Pink Island Form’ (formerly classified as A. borealis). A pink variant of a normally white flowered California native, received from the Santa Barbara Botanic Garden. It forms broad mats of dark green leaves, with clusters of rich pink blossoms rising continually on 2’ stems, late spring to fall. We are also growing a race of short-stemmed, white flowered plants from the high Sierra.
millefolium. As it is now conceived, this is the most cosmopolitan of all yarrows, circling the Northern Hemisphere. It makes a dense mat of finely dissected leaves, deep to pale green in color. The flower clusters are broad and well elevated above the foliage. Normal flower color is pure white to what might be described as “dirty cream”, though pink variants are occasionally seen in the wild. Hybrids with other species have greatly extended the color range (see Galaxy Series above). ‘Red Beauty‘ is one of the smaller cultivars with attractive dark green, fernlike leaves. Its 18" stems carry crimson flower heads throughout the summer months. ‘Snowsport‘ has lighter green foliage, 18-24" stems and thick clusters of snow-white flowers.
‘Moonshine’. I have grown at least three different selections claiming this name, usually under the “species” taygetea (which the British now treat as a single cultivar). This is all very confusing. The latest incarnation, which at least satisfies recent textbook descriptcations, has attractive grey-green stems and leaves and broad heads of bright yellow flowers, presented from mid-spring to fall if the spent flowers are removed.
tomentosa. Dwarf Yarrow. This species produces dense green mats, the flowers carried just above the foliage. Its smaller forms are sufficiently well-behaved for the rock garden. ‘Maynard’s Gold’, also known as A. t. ‘Aurea’, is the most robust of the cultivars I have grown, making a broad, slightly greyish green mat with flower stems up to 6" high. The flower heads are unusually broad and colored a vibrant yellow. ‘King George’ is a smaller plant with greyer leaves and creamy yellow flowers.