I don't care for the way the black plastic edging looks, but if you don't mind it, you can mow over it if it's buried flush with the grass. Shouldn't cause a water issue if it's flush.

Do a search on "edging" on this forum for lots of past discussions about the pros and cons of various edging materials and methods.

We used it here. Not because we LIKED it, but because it was cheap (we got a ton of it for about 25% of the price, that should tell you something about its "value"!). It's also easy to install and you get a clean edge between turf and border and that's important if you haven't time or inclination to edge borders.

That said, we have been working to eliminate it. It heaves with the relentless freeze/thaw cycle in New England. The pressure treated stakes we used DO rot, as well as heave (throw out the silly "pins" provided with the stuff. Make your own stakes, 12-16"L of pressure treated lumber). And it's really pretty homely. BUT, for us it served a purpose and it fit the budget.

We're edging some borders, dividing and transplanting groundcovers in others. The biggest project though, is the creation of a low, stacked stone wall around the planting that surrounds "Sanitary Ridge" (an ugly raised septic system). The pallet of stones is here, and my summer "project" awaits.

You have to use the things that will allow you meet your goal. Our chief constraint was money and then time. The plastic stuff "bought" us some of each. We never regarded it as "hardscape", though!

I took saypoint's advice and did a search. I only read a few before I realized that perhaps my first and real question is.....
Will Fescue creep into my beds? I guess I was thinkin maybe it
wouldn't but after reading some of the posts I got the implied impression that it would?
If it doesnt I probably won't bother. If it does I will continue to consider using it.
Thanks,
Mary

Mary,
In a recent post about edging (can't remember if it was this particular forum) many people used the "trench" method - - dig down deep, then fill with mulch. You get a nice natural border that way. I'm guessing you don't get much creep from neighboring stuff if you dig deep enough.

I've mentioned this in other threads, but I trench the edges of my lawn with a flat spade, and then use the string trimmer turned vertically every few weeks to beat back the encroaching lawn of fescues and clover.

I think you will find the plastic edging will end up being an eyesore over time. I dig down vertically 8" and then about 12" out come in at a 45 degree angle to meet the bottom. Then mulch the heck out of it, stomp it down pack it in. Affter about 4-5 years the mulch decomposes and you will start to get grass runners into the bed but they pull out relatively easy. every 5-8 years you will need to spade the whole thing again, but you just toss grass and mulch in a compost pile and refill with mulch.

This may sound weird, because I guess you can do it either way, but do y'all have the vertical cut on the outer edge and angle into the bed, or cut vertically at the bed edge and angle the outside edge?

When I first started trying to trench edges, I did the latter--cut straight down at the actual bed edge and made the 45 degree angle cut a few inches farther out, because that seemed the most natural way to work the edge when standing outside of the bed. Then later, I saw diagrams of the opposite, which gives a very clean straight lawn edge; but it seems like you would have to stomp in your flower bed to do that.

??

The angled portion extends into the bed, with the vertical cut at the lawn side. I don't angle my cuts, I just cut straight down with a flat spade, and flip a chunk of sod out into the bed by pushing down on the spade handle and then lifting the chunk. You can shake out the soil and remove the grass and roots, or remove the whole lump the first time, and just shake them out when you neaten the edges occasionally later on, when there is less material to deal with.

If you want an angled trench, cut downward to slice the bed edge, then cut the angled part from the side by shoving the spade in horizontally, but at an angle. For new beds, you can walk in the bed and cut the angle that way, but not for existing beds. I don't bother with the angle.

Thank you for description, saypoint.