I use the green steel stuff. I think the heavy top edge black plastic is also ok. I have used the pound in plastic also, but it is best as a barrier to the neighbor's bermuda grass.

I use the steel edging, also.

Lesson learned - if using rock, brick or pavers where you have St. Augustine, put the steel down first, then cover with the other stuff!

Hehehe. St. Augustine will climb over most anything, if left unattended.

It really likes washing machine discharge, though. All that laundry detergent suits it real well. (In Florida, anyway.)

Of course, here, the heat plus dryness, kills everything.

Yes, St. Augustine WILL climb over almost anything, but it is so much easier to pull out than Bermuda. I edge about 4 inches from my edging, and this eliminates the runners from going into the bed.

We use the 8-foot landscape timbers for our main raised edibles bed, stacked 3 high & held in place with rebars staked through holes drilled at each end. That raises the bed about 8 to 10 inches (at the edges). We build up dirt toward the center of the bed (8 by 15 feet) many more inches.

For some of our foundation plantings and out by the sidewalk, we use lengths of a black plastic that comes in 20-foot strips about 6 inches high and has a big, rounded upper lip. We partially bury it, and that raises the bed about 4 inches at the edges. The plastic is flexible so we can fashion curves with it. It's mostly self-supporting by the way it's shaped at the opposite from the top lip, with a kind of v-shaped "dirt catcher" lower lip. I don't even remember if we had to stake it...we probably did nail something to the bottom lip to bury in the ground, whether it was what came with the plastic or something we fashioned ourselves.

We'll use the plastic until it wears out, then go to stone and/or steel.

I have a lot of areas with the green steel edging, but it is starting to look a little rusty. We had landscape timbers along the front sidewalk we just pulled up because we had the city out to replace some sections of sidewalk that had sunk and was dangerous (the sidewalk, not the timbers). We're going to replace all that with stone and probably put stone in front of the metal edging to hide it - eventually. I would like to get rid of all the landscape timbers because most of them are rotting. We also keep the lawn grass scalped back about 3-4 inches from the edging. That way we don't have to weed eat every week when the lawn needs mowing.

I've used everything at one time or another. And the easiest thing to use is no edging. This did not seem possible until I was driving through Highland Park - very expensive neighborhood, with professional gardeners. I noticed all their flowerbeds and shrubbery rows were raised on .almost berms of soil with plenty of mulch. At the edge of the gardens were 6" trough full of mulch. Using that method no grass sneaks in under rocks or edging infiltrating the whole bed before you know it. You can easily stab down through the mulch and catch any grass.

I am saying this even though I have bought tons and tons of rock for walls and edging. Ants love it. Grass hides in it. I will continue to spray my rock walls with roundup every month to keep the grass from going under, around, between and through it. I will pour boiling water on it to get rid of ants. It looks great, but I don't recommend it.

I quit using the metal edging because it would have caused injury if you fall on it, my dd has a little balance problem, and I'm overprotective.

Thanks txgardenlady, you said what I did not make clear.
We mostly go with NO edging too. For reasons you gave.

But since the question seemed to ask for something tangible, I mentioned our main tangibles.

Very soon, I will be creating a raised bed for a patch of cannas, recycling (as bed "walls") four concrete "thingies" that formerly took the pouring-out runoff from our downspouts and moved the water away from the foundation. (I really should know the word for those things! Splashguards? Runoff guides?) Anyway, I think they'll look really good, once I get them set on-edge in the ground.