Seattle has its fair share of invasive weeds, but none are as notorious as giant hogweed (Heracleum mantegazzianum). Known for its towering height and umbrella-like white flower clusters, giant hogweed is more than a nuisance — it’s a toxic plant that can cause severe burns, blisters, and even permanent scarring.
At Lee’s General Landscaping, we’re trained to safely identify, remove, and dispose of giant hogweed infestations so you don’t have to risk your health.
How to Identify Giant Hogweed
This plant is huge and hard to miss once mature. Key identifiers include:
- Height: Can grow 10–15 feet tall.
- Stems: Hollow, thick (2–4 inches), with purple blotches and coarse white hairs.
- Leaves: Huge, jagged, deeply lobed leaves up to 5 feet wide.
- Flowers: Large umbrella-shaped clusters of small white flowers, spanning 2–4 feet across, blooming June–July.
- Habitat: Found along streams, vacant lots, roadsides, and neglected gardens in the Seattle area.
⚠️ Warning: Giant hogweed looks similar to cow parsnip and Queen Anne’s lace, but its size and purple-streaked stems are the giveaway.
Why Giant Hogweed Is Dangerous
- Toxic sap: Contact with skin, followed by sunlight, causes phototoxic burns — painful blisters, permanent scars, and even blindness if sap gets in the eyes.
- Spreads aggressively: Each plant produces up to 50,000 seeds, which can remain viable for years.
- Environmental impact: Outcompetes native vegetation, destabilizes soil, and worsens erosion along waterways.
- Legal status: Classified as a Class A noxious weed in Washington. By law, it must be eradicated wherever it’s found.
How We Safely Remove Giant Hogweed
Because of the serious health risks, this is not a DIY project. Our crew follows strict safety procedures:
- Protective Gear
- We wear heavy gloves, protective suits, and face shields to prevent sap exposure.
- Careful Cutting and Digging
- Plants are cut at the root crown (4–6 inches below soil).
- Large infestations may require multiple visits.
- Bagging and Hauling
- All plant parts, especially flower heads, are bagged immediately to prevent seed spread.
- Waste is disposed of at approved facilities — never composted.
- Follow-Up Suppression
- We monitor the site for seedlings and recommend mulch, landscape fabric, or replanting with natives to prevent regrowth.
Long-Term Control
- Act early: Removing seedlings is far easier than removing 12-foot giants.
- Don’t mow or weed-whack: This sprays sap and seeds — extremely dangerous.
- Report infestations: King County asks residents to report hogweed sightings since it’s a regulated noxious weed.
- Professional monitoring: Multiple years of follow-up may be needed to fully eradicate an infestation.
Professional Giant Hogweed Removal in Seattle
Attempting to remove giant hogweed yourself can lead to serious injuries. Professional removal ensures safety, legal compliance, and long-term control.
At Lee’s General Landscaping, we provide:
- On-site inspection and plant identification
- Full safety gear and removal process
- Proper bagging, hauling, and disposal
- Mulch and suppression to prevent regrowth
- Ongoing monitoring for new seedlings
✅ If you’ve spotted a massive plant with umbrella-shaped white flowers and purple-speckled stems, don’t touch it. Contact Lee’s General Landscaping immediately for professional giant hogweed removal in Seattle. We’ll keep your yard safe, clean, and free of this dangerous invasive weed.
