The invasive root system and strong growth can damage foundations, buildings, flood defences, roads, paving, retaining walls and architectural sites. It can also reduce the capacity of channels in flood defences to carry water.
And it has taken root in our backyard behind our shed.
I tell my colleague (who happens to be a master gardener) about the invasion. She says, "Ooooo Mommy...that's not good. Not good at all. That stuff can come up through concrete. Once you have it it takes a lot of work to get rid of it."
So, based on my colleague's instructions on how to kill the unkillable, today Chris and I undertake the arduous task of trying to eradicate the invader.
Step 1: Pull and dig out each plant as deep as you can. The knotweed has a taproot that can be as long as two feet. This step is a pain in the butt as the plants root themselves pretty firmly and require a LOT of digging and pulling.
Step 2: Pour a good 3-5 count of white vinegar into the hole where the taproot remains.
Step 3: Smother the area where the knotweed was growing - cover with black plastic and heavy rocks so that no sunlight or water can get to the taproot, which will regrow if given the chance
Step 4: Bag the plants you have pulled up in a plastic bag and toss them in the garbage. According to a few websites I checked out you should NOT put these in with the compost because they can live for a while, re-root and grow again thus spreading to other parts of the state.
Step 5: Repeat Steps 1-4 when the knotweed reappears and grows through the plastic (which, according to my colleague, it will...)
The score so far...
Chris & Jenn: 1
Japanese Knotweed: 0
Bring it on, blasted plant! We're ready for you!