Weeding the North Border: Organic responses to totally noxious invasive rhizomatic weeds and vines in an established border

Like many yard keepers, I share a "problem" border with a neighbor. You know the one I'm talking about--it's totally overgrown with some unknown invasive plant or plants and straddles the property line, making it a shared no-man's land.

Mine is on the north border of our property. It used to be someone's showpiece, I am certain, because it has some amazingly beautiful old flowering bushes, ground covers, and a few lonely crocus, hosta and other flowering bulbs, which have, of course, been completely overtaken with multiple invasive plants: a rhizomatic weed that keeps springing up no matter how much root you think you've gotten, at least two and probably three species of vine, including oriental bittersweet and things that look like grape vines but aren't. Oh, and possibly poison ivy. Yay.

I've conveniently ignored it for two summers, and finally last August, when the vines starting shooting out of the tops of every bush, smothering the mountain laurel and growing up into my dogwood, I realized that if I don't deal with it soon it will get so out of control it will be impossible. 

But, my problem is that I can't just dig up the entire border if I want to keep the old, established bushes.  Rooting out roots indiscriminately isn't an option--not to speak of the dangers if there is poison ivy root. And I don't just want to put down landscape fabric and mulch, because I want to plant more bushes there--a lilac, a witch hazel, hydrangeas--, and, ultimately I want to add perennials: peonies, maybe daisies, russian sage, cone flower. 

I can completely see a beautiful perennial flower border here. So, I need a living, breathing soil. Preferably clear of rhizomes, vine root systems and poison ivy.

Yesterday, after a fair amount of reading and research, I finally started to tackle it. Yes, in the SNOW!

And no, I'm not crazy. I have a plan. 

My plan is to play a long-game war for as long as it takes to smother, slash and uproot the weeds without affecting the existing flowering bushes, i.e., organic war. I'll wait as long as it takes. When they're gone, I'll plant.

So, first things first, here are the beautiful old flowering bushes in the border, from front to back.

The first two are a hardy blue-eyed daisy shrub side-by-side with an andromeda (pieris japonica). I can't find any mention  online of a hardy blue-eyed daisy, but in fact, I seem to have one. Here is what it looks like now (the privet hedge in the background is the neighbor's front yard):

Here's the Andromeda, now:

And here they are last August, completely overrun with multiple vines into one gargantuan monster bush. Ouch.

Behind the andromeda is a large, pink azalea on the neighbor's property, which the neighbor keeps well-weeded, shown here as it looked yesterday: 

And here, last August:

And then, underneath the dogwood is a very small white azalea, which you can see to the left and behind the dogwood here, in August:

Then from left to right (standing in my property), there is a medium-sized white rhododendron, a real mountain laurel, and another andromeda. Here are two photos, showing their relationship to the dogwood and to each other, taken from one of my second-story windows, yesterday:

And here is where the trouble starts. First, the land drops off in a gentle hillside and starts to be in full sun. The top of the hill is my property. The bottom is the neighbor's. But I don't know where the property line is. As I haven't weeded on my side of the property for two summers, by last August it was a nightmare:

At the far end, impossible to pick out in the tangle of weeds, is a beautiful old bush that has white flowers in June. No idea of its name.

These feathery weeds are taller than me. And, as I have been battling smaller versions of them on the patio for two years, I know that they propagate by rhizomatic roots that will resprout from the tiniest fragment left in the ground. Here are they are now, in dead of winter:

And here, in close-up:

 Those rhizomes are already sprouting new leaves, here, more visible on the patio:

My plan is to cut down all the canes to the ground and cover everything with black landscaping fabric, the polypropelene kind. I'll leave it down for the summer, then take it up and chop down anything, put it down again, and do the same thing again next spring, and the next, until the roots are dead.

I am imagining, though, that the rhizomes and vine root system will try to migrate and sprout out beyond the fabric, in the yard. So, when that happens, I will probably have to dig out whatever is coming up beyond the fabric. I haven't talked to the neighbor yet, but I will, because unfortunately,  I think, being no respecter of boundaries, the weeds will try to grow out on her side too, of course.

In fact, I've found a website from a guy who recommends this very thing for Japanese Knotweed (though my problem plant doesn't seem to be knotweed). Still, here's good description and link here.

For instance, you may wish to keep a tarp over the bulk of the problem area during the warm weather months, slashing/poisoning along the perimeter as necessary. Then, in late autumn/early spring, dig up as many of the rhizomes as you can (again, if only to ensure even ground for your tarps, lest they be punctured). Afterwards, place the tarps back on -- even though winter is on the way. You want the tarps to be already in place for the next growing season. That way, in case you get busy with your gardening in the spring and find yourself pressed for time, you don't have to worry about remembering the tarps.

So, yesterday, in the snow, I started. And I got quite a respectable pile of brush, in the few hours I worked.

And a pretty coating of onion snow, to boot.