If you’ve spotted a tall, bamboo-like plant with broad leaves and clusters of tiny white flowers in your yard, chances are you’re dealing with Japanese knotweed — one of the most aggressive invasive weeds in Seattle.
At Lee’s General Landscaping, we’ve helped many homeowners take back their yards from knotweed infestations. Here’s what you need to know.
What Is Japanese Knotweed?
Knotweed was originally brought to the U.S. as an ornamental plant, but it quickly became a noxious invasive weed. In Seattle, it’s commonly found in yards, along fences, and near waterlines. It grows up to 12 feet tall, spreads underground with powerful rhizomes, and can push through asphalt, patios, and even building foundations.
Why Knotweed Is a Problem
This isn’t just a nuisance plant — knotweed is destructive:
- Spreads quickly: Its rhizomes can grow 30+ feet underground and sprout new shoots anywhere they reach.
- Damages property: Knotweed can crack pavement, lift retaining walls, and compromise foundations.
- Harms the environment: It crowds out native plants and destabilizes streambanks, increasing erosion.
- Hard to kill: Cutting it down only makes it come back stronger — even a tiny root fragment can regrow.
Because of these issues, Washington State classifies knotweed as a noxious weed, and landowners are responsible for controlling it.
Safe and Effective Removal Methods
There’s no quick fix with knotweed, but there are safe ways to control and remove it:
- Mechanical Removal
- We cut and dig out knotweed using commercial tools.
- This often requires repeated visits since rhizomes are extensive.
- Excavation and soil screening may be needed for severe infestations.
- Herbicide Treatments
- Selective herbicides (applied properly and legally) can weaken rhizomes over time.
- Herbicide should never be used near vegetable gardens or without proper safety training.
- Combination Approach
- The most effective strategy is often a mix of cutting, digging, and carefully timed treatments.
- Installing landscape fabric and mulch afterward helps suppress regrowth.
At Lee’s General Landscaping, we design a custom plan for each property, balancing safety, cost, and long-term control.
Professional Hauling and Disposal
You can’t just toss knotweed in the compost bin — it can re-root and spread. We bag, haul, and dispose of knotweed waste properly at approved facilities to prevent reinfestation.
Why Hire Professionals for Knotweed Removal?
DIY attempts often make knotweed worse. Because the plant can regrow from tiny root pieces, cutting it down without follow-up just fuels the infestation.
Hiring professionals ensures:
- Root-level removal with commercial equipment
- Safe disposal so knotweed doesn’t spread
- Preventative measures like mulch and fabric to protect your yard
- Long-term monitoring and control
Lee’s General Landscaping: Seattle Knotweed Removal Experts
Knotweed requires persistence, knowledge, and the right tools. At Lee’s General Landscaping, our crew has hands-on experience tackling knotweed across Seattle and King County. We offer:
- Knotweed identification and inspection
- Step-by-step removal and treatment
- Haul-away and safe disposal
- Mulch installation for ongoing suppression
- Follow-up plans to keep your yard knotweed-free
✅ If you’ve found knotweed on your property, don’t wait — it only spreads faster. Contact Lee’s General Landscaping for a professional consultation and let us help you reclaim your yard.
