Japanese Knotweed (Fallopia japonica)
Description
- Native to eastern Asia
- Small green-white flowers grow in showy plumes off stem and leaf joints
- Stems are hollow and bamboo-like, with reddish-brown speckles
- Leaves are heart-shaped and 8-10 cm across
- Zig-zag pattern of leaf arrangement on the stem
- Grow just about anywhere including waste sites, along roads, in meadows and wooded areas and along streambanks
Consequences of Invasion
- Dominate stream banks
- Increases erosion
- Degrades wildlife and fish habitat
- Reduces sight lines and block access to water bodies for recreation
- Can grow over 3 m in a year
- Able to grow through cement, house foundations, and walls
- Extensive root systems are capable of resprouting even after many years of control
- Roots can break off and float downstream to form new infestations
Prescription for Control
- Cutting is not effective
- Most effective way to eliminate it is to use a stem injector to inject stems with herbicide
- Very important to control sprouts in new areas
- Will not compost effectively
- Must be bagged and buried deep in a landfill
- Must be managed consistently through the growing season
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