Batten Blooms
Cow Parsley
Anthriscus sylvestris

Cow Parsley

3a–8bHardiness zone
SpringSummerInvasive
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
Peak bloom
Summer
Not in bloom
Fall
Not in bloom
Peak bloom
In bloom
Background

Cow parsley (Anthriscus sylvestris) is a European native biennial or short-lived perennial in the carrot family (Apiaceae), naturalized across much of North America. It produces tall hollow stems topped with flat white umbels in mid-spring along roadsides, hedgerows, and woodland margins. The cultivar 'Ravenswing' is widely grown as a garden ornamental for its deeply cut, near-black foliage and is the primary reason gardeners plant this species intentionally.

Plants form a basal rosette in year one, then bolt to 3–5 ft in year two, set seed prolifically, and die. Self-seeding is aggressive on disturbed, fertile ground. Dangerously easy to confuse with poison hemlock (Conium maculatum): always check stems before handling any unidentified Apiaceae - hemlock stems are glabrous with purple blotches, while cow parsley stems are distinctly hairy and unspotted. Prefers moist, fertile soil and tolerates considerable shade. A neutral to slightly alkaline pH suits it well.

The roots contain deoxypodophyllotoxin and podophyllotoxin, compounds with documented antitumor and antiviral activity used as pharmaceutical precursors. Young spring leaves have a mild flavour and have been used as a parsley substitute in European traditional cooking. Plants provide early-season nectar and pollen to hoverflies and other pollinators before many other umbellifers come into season.

Good companions
YarrowChamomileComfreyWild Aster
Care guide
SunSun to part shade
WaterModerate
SoilAny; moist, fertile ground preferred
SpacingDo not plant in open garden - self-seeds prolifically
Height3–5 ft
Zone3a – 8b
Frost hardyInvasive
Seasonal tasks
winter
sowDirect sow seed into prepared, weed-free soil and leave it outdoors to cold stratify naturally; sow shallowly, as most small seed needs light to germinate.
spring
watchMonitor for powdery mildew and fungal leaf spot as growth becomes dense in late spring.
watchCheck emerging rosettes - hairy green stems and a faint parsley scent confirm cow parsley; toxic hemlock has purple-blotched, hairless stems.
summer
cutRemove spent umbels before seeds fully ripen to limit self-seeding; bag and dispose rather than compost.
buyOrder seed - about two months before sowing
buyOrder seed - about two months before sowing
fall
sowDirect sow seed into prepared, weed-free soil and leave it outdoors to cold stratify naturally; sow shallowly, as most small seed needs light to germinate.
cutCut dead stems to ground level in late fall to tidy the planting and reduce overwintering disease spores.
sowDirect sow seeds; they require cold stratification through winter and germinate the following spring.