Blue Boy Clematis vs Cow Parsnip - TreeTime.ca

Blue Boy Clematis vs Cow Parsnip

Heracleum maximum

Clematis integrifolia Blue Boy

CUSTOM GROW

NOT AVAILABLE THIS SEASON - MIGHT RETURN

Cow Parsnip
Blue Boy Clematis

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.

Blue Boy Clematis is a cold-hardy, fast growing, woody climbing vine. Hundreds of stunning steel-blue bell shaped flowers adorn the vine throughout the summer that droop and appear to hang in the air. The fibrous stems spread and create a fan-like symmetry shape.

This species will do best with support from a trellis, fence, or even other shrubs or tree stumps.

The Blue Boy Clematis was developed in Manitoba, Canada in 1947 by famous breeder Frank L. Skinner by crossing C. integrifolia x C. viticella, but it didn’t gain popularity until the 1990’s.

Cow Parsnip Quick Facts

Blue Boy Clematis Quick Facts

Zone: 2a
Zone: 2b
Height: 1.8 m (6 ft)
Height: 3 m (10 ft)
Spread: 1.2 m (4 ft)
Spread: 0.6 m (2.0 ft)
Light: partial shade, full sun
Light: partial shade, full sun
Moisture: normal, wet
Moisture: normal, wet
Growth rate: fast
Growth rate: medium
Life span: short
Life span: medium
Growth form: upright
Spreading: seeds - low
Suckering: medium

Toxicity: sap causes skin irritation

Foliage: very large, palmate leaves
Flowers: large clusters of white flowers
Flowers: steel blue
Bloom time: spring to early summer
Hybrid: no
Hybrid: yes
Catkins: no
Catkins: no


Native to: AB, BC, SK, MB, ON, QC, NS, NB, NL, YT, NT, PE
Other Names: american cow parsnip, common cow parsnip