Achillea millefolium
common yarrow
compoSitaeFlat heads of red, white, or pink flowers;
ferny, dark green leaves
2–3 ft. high; 2 ft. wide
Full sun
Blooms June–August
Zones 4–8
pruning Young plants can be
deadheaded to lateral buds for
summer-long bloom. With age or when
grown in conditions that promote
leggy growth, such as very wet condi-
tions or hot weather early in the season,
plants may need to be cut back (hedge
shears work well) by a third to half after
first bloom to prevent flopping, then
sheared again down to basal foliage as
the second bloom phase is completed.
Plants often send up sporadic small
blooms from basal foliage. Deadhead-
ing prevents seeding. Cutting plants
back by half or two-thirds before
flowering in early June, or when about
18 in. tall, can produce shorter, stockier
plants that are self-supporting early in
the season, though they may still flopslightly by late season, depending on
other growing conditions. Flowers are
smaller but more numerous on
cut-back plants and flowering may be
slightly delayed. Cutting back after
flower buds form may mean no bloom
for the season. These aggressive
yarrows often need pruning to keep
them in their own space. Cut foliage
and roots back, if necessary, to give
neighboring perennials room. Leave
basal foliage over the winter. Cut
back any damaged sections in the
spring if needed.
other maintenance Invasive
habit, plants can spread 2–3 ft. in a
season, and a good deal of mainte-
nance is required to keep plants in
bounds. Plants require staking if not
cut back for height control. Division in
spring or fall every couple of years
keeps plants vigorous.
related plantS The Galaxy
Hybrids (Achillea millefolium × Achillea
‘Taygetea’) offer a variety of outstand-
ing colors, but the plants are
short-lived in my experience and flop
and spread like the species. Achillea
millefolium ‘Fire King’ is aAchillea millefolium