Source for good quality, practical edging to encircle shrub
I recently planted three shrubs (Corylus americana, or American hazelnut) in a buffer area between my townhouse row and a public park. The shrubs are located just next to a "privacy screen" of white pine trees. The homeowners association sends massive lawnmowers to mow the strip of grass between the pine trees and the townhouse row. I would hope that the lawnmowers avoid any collision with my new shrubs, but will feel more confident after installing some good edging around the shrubs.
The edging must be formable into a circle (flexible, in small sections, or both). Should be wood or metal, not the cheap black plastic edging that all the discount stores carry. Please suggest mail-order sources.
I found some cedar edging in Lowes that is almost but not quite what I want. The cedar edging comes in sections of seven pieces, held together by a plastic tape strip and staples. Only the outer two wooden pieces (out of seven) are sharpened at the bottom to allow driving into the ground. I would be satisfied with this type of edging if every piece was sharpened at the bottom and could be driven like a stake (7/7 rather than 2/7).