Cow Parsnip vs Lewis Mock Orange - TreeTime.ca

Cow Parsnip vs Lewis Mock Orange

Philadelphus lewisii

Heracleum maximum

COMING SOON

(new stock expected: fall of 2026)

CUSTOM GROW

Lewis Mock Orange
Cow Parsnip

Lewis Mock Orange is a flowering ornamental shrub that produces an abundance of white, fragrant blooms. The flowers have a sweet scent similar to orange blossoms, with a hint of pineapple. They bloom for several weeks from late spring to early summer, attracting pollinators and other beneficial insects.

Native to North America, Lewis Mock Orange is found from the southernmost portions of Alberta and British Columbia, and south into the northwestern United States. It makes an attractive shrub and can be used in hedgerows, pollinator gardens, and naturalization projects. Blooms occur on the previous year’s wood, so it is recommended to prune after it has finished flowering.

Cow Parsnip is a native perennial wildflower known for its tall growth, very large leaves, and broad clusters of white flowers. The abundant blossoms provide nectar and pollen for a wide variety of pollinators, including bees and butterflies. Birds and small mammals feed on its seeds, while the foliage serves as a larval host for certain butterfly species.

Cow Parsnip is often among the first native perennials to establish in disturbed or open sites. It typically grows in moist meadows, along streambanks, forest edges, and roadsides. Although usually a short-lived perennial or biennial, it readily self-seeds and maintains strong populations where conditions are favorable.

Cow Parsnip is the only native Heracleum in North America and should not be confused with the highly invasive Giant Hogweed (H. mantegazzianum).

Note: The sap of the Cow Parsnip can cause phytodermatitis when exposed to ultraviolet light (sunlight). This can cause rashes or even burns. Care should be taken if pruning or handling this plant.

Lewis Mock Orange Quick Facts

Cow Parsnip Quick Facts

Zone: 4a
Zone: 2a
Height: 3 m (10 ft)
Height: 1.8 m (6 ft)
Spread: 2.4 m (8 ft)
Spread: 1.2 m (4 ft)
Light: partial shade, full sun
Light: partial shade, full sun
Moisture: dry, normal
Moisture: normal, wet
Growth rate: medium
Growth rate: fast
Life span: medium
Life span: short
Growth form: upright to arching, multi-stemmed
Growth form: upright
Spreading: suckering - medium, seeds - low
Spreading: seeds - low


Toxicity: sap causes skin irritation
Foliage: very large, palmate leaves
Flowers: fragrant, white
Flowers: large clusters of white flowers
Bloom time: mid spring to early summer
Bloom time: spring to early summer
Hybrid: no
Hybrid: no
Catkins: no
Catkins: no


Native to: AB, BC
Native to: AB, BC, SK, MB, ON, QC, NS, NB, NL, YT, NT, PE
Other Names: california mock orange, lewis mockorange, western mock orange, western syringa, wild mock orange
Other Names: american cow parsnip, common cow parsnip