With this method there is no need to cut canes, or handle viable plant material for disposal. Canes too small to inject can be injected upon secondary follow up visit.
When? Injections can be made anytime during the growing season.
What to use? Glyphosate (surfactant free) is the primary herbicide for use in control of knotweeds. An Active Solution of at least 41% Glyphosate is required. Many Stores carry Glyphosate at lower percentage active ingredient, but for stem injection you need greater than 41%. Other herbicides have been reported to work but operators will want to verify with local application regulations.
PRODUCTS (USA): Aquamaster. Rodeo. Imazapyr. Roundup Super Concentrate.
Why inject below the third node for Japanese Knotweed?
If plants were injected above the third nodes only the upper portion of the canes will be affected. The rhizome structure will survive to propagate.
Where application rates were maintained at the recommended 3-4 cc’s per injection, control project-wide was 98%.In the course of making applications, occasionally stems will be overlooked and not treated. Follow-up is a key element of successful removal of any invasive species. Using the recommended injection rates plus careful application techniques will produce the best results..