Japanese Knotweed

In addition to the Horsetail problem we have a Japanese knotweed problem which is resisting almost everything I spray on and around it. I use high amounts of ammonium sulphamate last year which helped but it came back this year. I used VERY high levels of Sodium Chlorate (why do all the good ones get banned?) this year but it just keeps dieing and coming back within a week.

Is Picloram the next best chemical to use?

Also should I cover the affected area with a tarp to stop the plant getting any sunlight?

 

Maybe some good old engine oil might do the trick?

 

Hi Andyh

Amateur Gardening had some useful hints on getting rid of knotweed recently. This method doesn't claim to get rid of it immediately, but it should weaken it so that other treatments work more effectively.

(1) Buy the smallest funnel you can find and glue an empty biro to it so that you have a thin nozzle which can be used for getting chemicals into the plant.

(2) Mix up some Bayer Tree Stump Killer as directed.

(3) Cut all stems of knotweed down to below their lowest leaf joints, to reveal their hollow stems.

(4) Insert funnel into each plant stem and pour a small amount of the stump killer mix into the plant. Revert to spray mixes for further treatments later in the year.

Hope this helps.

 

There is a herticide available from aggricultural suppliers, called, "Tordon.22k"
This will kill Japanese Knotweed after a couple of applications.

Engine oil, Diesel, Glysophate,or covering with a tarp will "not" work
Knotweed is very resilient, if you cover it with a tarp it is capable of growing up to five metres underground to find a way out. Also you can eat it, it tastes like rhubarb.


John.

 

So St John says you can eat it!

or

you can

 

:rotfl::hehe::lollol:

 

Tordon.22k = Picloram