Commonly asked questions

How Do I Manage Japanese Knotweed?

Per Hoboken City Code, property owners are responsible for caring for street trees and tree pits in front of their property, as well as all vegetation on their private property. Japanese Knotweed (Polygonum caspidatum) have been increasing in prevalence in Hudson County.

These are perennial plants  that are native to Japan. The plant forms in large clumps up to 13 feet tall and produces small greenish-white flowers. Once established, it is extremely persistent. Reproduction occurs both by vegetative cuttings and seeds, making this plant extremely hard to eradicate. Once introduced it spreads rapidly by rhizomes and is extremely competitive.

Below are some suggestions to manage Japanese Knotweed:

Strategy 1: Dig it Out

Small stands of the plant can be mechanically dug out, like a weed. Once removed, shade the area with black plastic, tarp or shade cloth to reduce additional growth.  

Strategy 2: Treat with Herbicides

Large stands of the plant can be chemically treated with herbicides.

Strategy 3: Contact an Expert

Consult a New Jersey licensed tree care expert who can inspect the issue and recommend solutions.

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