Data provided by the participants of the Consortium of California Herbaria

View additional distribution information on the Jepson eflora

Cow Parsnip (Heracleum maximum) is a member of the Apiaceae (Carrot) family and the only member of this genus native to North America. Cow Parsnip is distributed throughout the continental United States and Alaska except the Gulf Coast and a few neighboring states. It is the only native member of this family to occur throughout the U.S. In California it occurs primarily in the northern half of the state. It is relatively large for an herb and features a large flower head consisting of the typical flat-topped umbels of the Carrot family. Chemicals in the plant may cause dermatitis in some individuals. It may be weedy or invasive in portions of its range.

Plant type

Perennial herb

Size

4 - 8 ft Tall

Form

Upright

Growth rate

Moderate

Calscape icon
Color

White

Flowering season

Summer

Special uses

Deer resistant

Sun

Partial Shade

Water

Low

Ease of care

Easy

Cold tolerance

Tolerates cold to -10° F

Soil drainage

Fast, Medium, Slow

Soil description

Tolerant of a variety of soils as long as sufficient moisture is provided.
Soil PH: 5.2 - 6.7

Sunset Zones

4*, 5*, 6, 7, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24

Site type

Meadows, moist places, wooded or open

Plant communities

Chaparral, Foothill Woodland, Lodgepole Forest, Red Fir Forest, Subalpine Forest, Valley Grassland, Yellow Pine Forest

Caterpillars
Butterflies

Butterflies and moths supported

3 confirmed and 3 likely

Confirmed Likely

Black Swallowtail

Papilio polyxenes

Anise Swallowtail

Papilio zelicaon

Epermenia californica