garden edging on a hill
I have a nice little flower garden at the bottom of a hill on a corner of my lawn. I want to make a stronger/better defined edge between the lawn and the garden, I've used plastic edging in the past but it just doesn't hold its shape. Over time the pressure of the hill warps the edging, tipping it over and not holding its form.
Anyone have ideas on how to make something more permanent? I don't know if there is commercial edging that is much deeper than what I found (maybe 4" or so), something more like 8 inches might hold. I also have some left over bricks - I was thinking of building something like a little retaining wall with those but I'm not sure if that would work. If the border wasn't curved I'd use PT lumber, drill some holes in it and use rebar to pound into the ground.
Any input would be appreciated!