Cow Parsnip vs Nuttalls Sunflower - TreeTime.ca

Cow Parsnip vs Nuttalls Sunflower

Heracleum maximum

Helianthus nuttallii

CUSTOM GROW

NOT AVAILABLE THIS SEASON - MIGHT RETURN

Cow Parsnip
Nuttalls Sunflower

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.

Nuttall’s Sunflower is a native perennial wildflower known for its bright, golden-yellow blooms. Flowering from mid to late summer, it offers a late-season nectar source for various bees, butterflies, and other pollinators, while the seeds provide a fall food source for birds. The upright growth habit adds structural height and visual variety to your landscape.

Nuttall’s Sunflower can be found growing in moist to wet meadows, prairies, and open spaces. It can spread quickly via underground rhizomes, making it ideal for large-scale plantings. It is well-suited for naturalization, soil stabilization, riparian zones, and wetland restoration projects. If planting in smaller urban yards or gardens, extra care and maintenance will be required to limit its spread.

Cow Parsnip Quick Facts

Nuttalls Sunflower Quick Facts

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

Toxicity: sap causes skin irritation

Foliage: very large, palmate leaves
Flowers: large clusters of white flowers
Flowers: golden yellow, daisy-like
Bloom time: spring to early summer
Bloom time: late summer to early fall
Hybrid: no
Hybrid: no
Catkins: no
Catkins: no


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