There are a number of cultivars of A. millifolium, but 'Paprika' stands out for me thus prompting this separate post. The facts below are very similar to the non-cultivar species except for the dusty-rose flower color and its shorter height when in bloom.
The photo below is a good representation of what you will find in the nurseries, with its upright stems and not too much else going on. This yarrow is good for meadow applications, where it can weave itself in and around other plants. Containers, too, and certainly beneficial to pollinators.
There are other cultivars that merit our attention, such as 'Terracotta', so make sure and research whichever desirable colors work with your design.
facts
Botanical Name: Achillea millefolium
Achillea: Honoree, mythological warrior Achilles, who used yarrow extract to heel wounds.
Millefoium: Having many leaves (or leaflets). For this species, the leaves have a fine texture.
Common Name: Common yarrow; milfoil
Family Name: Asteraceae
Origin: Native; Northern Hemisphere
design considerations
Positioning: Foreground, under foot (infrequently), allowed to move freely
Garden Themes: Native/Mediterranean/dry, cottage/informal, pollinator, wildflower, rain
Uses: Meadow/prairie, habitat, container, cut flower (fresh or dried), mass, border, edging, ground cover, lawn substitute (with limitations), green stormwater infrastructure
identifying characteristics
Type: Herbaceous perennial
Form: Mat, basal, erect clump
Texture: Fine
Size: 8" tall and spreading, but to 2' tall when in bloom
Outstanding Feature(s): Flower
Stem: Gray, gray-green, silver; underground rhizomes
Leaf:
Type: Pinnately compound (tetraploid, with leaflets arranged three dimensionally)
Arrangement: Alternate
Shape: Oblong
Margin: Entire
Color: Gray-green, light green, silver
Surface: Feathery
Flower: Summer to Autumn. Showy, dense compound corymbs, dust-rose fading to copper or pink.
Fruit: Autumn. Tiny achenes, readily viable
cultural requirements, tolerances & problems
Sunset Zones: A1-A3; 1-24
USDA Zones: 3-9
Light: Full sun
WUCOLS SF Bay Area Hydro Zone: Low (non-cultivar species; Medium for cultivars)
Soil:
Texture: Sand, loam, clay
Moisture Retention: Well-drained
pH: Highly acidic to highly alkaline
Tolerances: Drought
Problems: May become invasive
Branch Strength: N/A
Insects:
Disease: Stem rot, powdery mildew, rust,
citations & attributions
Bayton, R. (2019). The Royal Horticultural Society's the Gardener's Botanical: An Encyclopedia of Latin Plant Names. London: Mitchell Beazley.
Calscape. "Common Yarrow." California Native Plant Society, Sacramento. Accessed on August 17, 2021, from https://calscape.org/Achillea-millefolium-(Common-Yarrow).
Fire Effects Database System. "Achillea millefolium." United States Department of Agriculture, Washington D.C. Accessed on August 17, 2021, from https://www.fs.fed.us/database/feis/plants/forb/achmil/all.html.
Norris Brenzel, K. (Ed.). (2012). The New Sunset Western Garden Book. New York: Time Home Entertainment, Inc.
Plant Finder. "Achillea millefolium." Missouri Botanical Garden, St. Louis. Accessed on August 17, 2021, from http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=277129.
Plant Finder. "Achillea millefolium 'Paprika'." Missouri Botanical Garden, St. Louis. Accessed on August 30, 2021, from https://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=241837&isprofile=0&.
Water Use Classification of Landscape Species. "WUCOLS IV Plant List." University of California, Division of Agriculture and Natural Resources, Davis. Accessed on August 17, 2021, from https://ucanr.edu/sites/WUCOLS/Download_WUCOLS_IV_List/.
Photos:
Nursery Plants: "Achillea millefolium Paprika 7zz" by David J. Stang is licensed under Wikimedia Commons.
Faded flower cluster: "Achillea millefolium Paprika 2zz" by David J. Stang is licensed under Wikimedia Commons.
Feature flower cluster: Purchased from Shutterstock.