Showy Aster vs Cow Parsnip - TreeTime.ca

Showy Aster vs Cow Parsnip

Eurybia conspicua

Heracleum maximum

CUSTOM GROW

CUSTOM GROW

Showy Aster
Cow Parsnip

Showy Aster is a native perennial wildflower recognized for its tall stems topped with clusters of light purple blooms. Blooming from late summer into autumn, it provides an important late-season source of nectar and pollen for pollinators. It also produces seeds that are eaten by birds, extending its value to wildlife beyond the flowering season.

Drought tolerant once established, Showy Aster grows well in urban, rural, and disturbed sites. With its mix of ecological value and ornamental appeal, it is ideal for pollinator gardens, naturalization projects, and ecological restoration.

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.

Showy Aster Quick Facts

Cow Parsnip Quick Facts

Zone: 2b
Zone: 2a
Height: 0.6 m (2.0 ft)
Height: 1.8 m (6 ft)
Spread: 0.5 m (1.5 ft)
Spread: 1.2 m (4 ft)
Light: partial shade, full sun
Light: partial shade, full sun
Moisture: any
Moisture: normal, wet
Growth rate: fast
Growth rate: fast
Life span: short
Life span: short
Growth form: upright, colony-forming
Growth form: upright
Spreading: rhizomes - medium, seeds - medium
Spreading: seeds - low


Toxicity: sap causes skin irritation
Foliage: very large, palmate leaves
Flowers: purple-blue, with yellow centers
Flowers: large clusters of white flowers
Bloom time: late summer to early fall
Bloom time: spring to early summer
Hybrid: no
Hybrid: no
Catkins: no
Catkins: no


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