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Hogweed

Heracleum sphondylium

Last reviewed: September 2026

Hogweed (Heracleum sphondylium)
Photo: no rights reserved

Toxicity unknown

Hogweed (Heracleum sphondylium) is not listed by the ASPCA Animal Poison Control Center (opens in new tab) or the other sources we check, so we have no verdict for it either way. Absence from those lists is not a clearance. If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.

Light

part shade

Water

medium

Size

24"–72" H × 12"–36" W

Bloom

May, Jun, Jul

Pollinators

bees, beetles, flies

Before you buy

Your city may pay you to plant this

Cities and water utilities offer rebates for replacing lawn with native and water-wise plants. We track 460 programs across 44 states, each with a link to the provider and the date we last checked it.

Find rebates in your area

Picture natives in your own yard

Wondering what could grow where Hogweed is now? Upload a photo of the spot and Patch Vision shows a rendering of it replanted with natives for your region.

Cow-parsnip is a tall, dramatic biennial with large umbrella-shaped white flower clusters that bloom from May through July. This robust plant can reach up to 6 feet tall with broad, deeply lobed leaves that create a bold textural statement in partly shaded areas.

In an HOA neighborhood

Hogweed takes more care to keep looking intentional in a front yard. Maintenance level: moderate. Consider it for backyard or mid-zone beds rather than the street edge.

Works well in: backyard only.

  • Very tall and wild appearance inappropriate for front yards
  • Dies back completely in winter leaving bare spots
  • Can cause skin irritation similar to giant hogweed

Wildlife value

The large flower clusters attract diverse pollinators including bees, beetles, and flies during the summer months. Seeds provide food for birds and small wildlife.

Common questions

How much sun does Hogweed need?
Hogweed grows best in part shade conditions.
When does Hogweed bloom?
Hogweed blooms in May, June, and July.
What pollinators does Hogweed attract?
Hogweed draws bees, beetles, and flies.
Is Hogweed HOA-friendly?
Hogweed takes more care to look intentional in a front yard. Consider it for backyard or mid-zone beds rather than the street edge.

Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

If something looks wrong

Common plant problems, and what to check first

These come up on almost any plant. Each guide lists the likely causes in the order they are worth ruling out, with one thing to check before you act on any of them, and links to the source it came from.

See all plant problem guides

Ready to grow Hogweed? Add it to your garden in Pollinator Patch to track it and get season-by-season care guidance.