Tips for edging driveways that nobody talks about

I put in 14-gauge Colmet steel edging along my 60-foot concrete driveway two summers ago to keep Tifway 419 Bermuda from jumping into the expansion gaps. Setting it flush with the concrete saved my weed eater line, but I found out the hard way that Bermuda runners don't care about a flat barrier. By mid-July, the stolons were literally vaulting straight over the top edge anyway. What acutally helped me was setting the steel roughly 1/4 inch lower than the concrete edge instead of perfectly flush, leaving just enugh lip to guide my stick edger blade down the concrete line without grinding metal on metal. Every couple of weeks I run the blade trough, and it slices anything trying to crawl across.

Also, definately second packing that trench solid. I used a hand tamper with moistened topsoil and sand along the yard side. If you leave loose dirt, the strip will start leaning toward the grass after a couple of hard rains and a mower wheel rolling too close.

I honestly don't know much about how grass spreads underground, but does Bermuda ever just tunnel right under the metal? Everyone keeps talking about the runners jumping over the top, but how deep does the strip acutally need to go into the dirt so roots don't punch under into the driveway base? Also, what happens near the street where a car tire might roll over the edge? whould driving over it just crush and bend that steel strip instantly, or is it sturdy enugh once the dirt is packed?

Bermuda rhizomes will punch four to six inches down easy if your sub-base has any sand in it. A standard four-inch strip won't stop the taproots, just slows them down.

Back before folks bought these thin prefabricated kits, we'd either pour a little three-inch concrete mow ribbon along the drive or drive half-inch rebar pins every four feet. If an errant tire rolls off the apron near the street, modern gauge steel folds flat into the mud in a heartbeat. Pin it deep with heavy rebar near the road edge, or you'll be out there with a wrecking bar straightening it out come spring.

Quick update — you guys got me paranoid about what’s happening underneath, so I dug down along a section this morning. Sure enugh, with my standard 4-inch strips, a few runners are alredy trying to sneak right under into the gravel sub-base. For anyone dealing with deep rhizomes, did you end up swapping out for 6-inch commercial edging, or is a concrete mow ribbon realy the only permanent fix?