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.
Update: 25 July 2022.
The border seems to be helping with the vines growing out of the bed, but not with the grass growing into the bed. The border was designed to be just at ground level, so we could mow the lawn with the tires of the lawn mower running along the top of the border.
But Bermuda grass sends out runners, above ground, and these seemed to really want to just go right over the border and into the bed. We need a higher border to stop the runners from just going right over the border.
So we got 20 feet of 4x4 limestone blocks from Whittlesey Brothers (27 June 2022, $36.90) and lined them up next to the border.
We bought a bag of mortar mix from Home Depot (25 July 2022, $8.64), and mortared the stones on top of the border.
This should keep the Bermuda grass out of the backyard bed.
It seems that after 3 to 4 months of pulling up every upstart vine we see in the back lawn, the roots have mostly stopped trying to send up more vines (unless they are just discouraged by the heat of a Texas summer, and lack of rain.)