Most of our beds are well separated from anything else. But we have one bed, in the backyard, up against the fence, that is not.
Linda planted a passion flower vine to grow along the fence, but, it turns out, it also sends roots out into the yard and tries to pop up vines all thru the grass. So our intention is to put a stone border around this bed, to keep the roots from getting into the yard.
The first step is to dig a trench around the bed.
Then, I tried to take it down deeper. The design was to bury a metal barrier that would block any roots from going into or out of the bed, and then pour concrete on top of that and put limestone blocks -- the standard 4x4 ones -- on the top.
I bought some corrugated metal landscape edging. Made by Dakota Tin, sold by Walmart $64.93. Two pieces, each 10 feet long and 12 inches tall. And a rubber mallet to hammer it into the ground partially below the concrete to be poured.
But digging down, we hit solid rock almost immediately. Just barely 12 inches below the surface. Apparently this section next to the fence was not excavated very far down.
We also uncovered two irrigation pipes leading into the bed -- one next to the concrete pad for the electrical box, and the other at the other end of the bed, next to the fence.
So the new design is to just use the metal edging as yet another part of the barrier -- forming one side of the concrete wall to be poured.
The corrugated tin had to be shaped to fit around the irrigation pipes and the uneven rock at the bottom of the trench. Then we bought the cement -- 15 bags.
and we position the metal barrier in the trench.
Then we pour the cement in the trench -- keeping the metal barrier to the inside of the cement pour. We top it off with a line of 4x4 limestone blocks, put the dirt that we dug out back and it is done.
We have been pulling out any of the vine starts that we see in the yard for the last few weeks; we will probably need to do that for a couple months until the roots that are in the back yard now are exhausted and die.