Edging Bermuda grass lawns really requires an edger if you want those perfect square lawns. Yes, I can do it with a trimmer / weed eater, but in the end, the edger is so much easier and faster and cleaner. You’ll see a LOT of people trying to teach methods using a weed eater, but in the end, Bermuda grass REALLY needs an edger for proper lawn edging.
The edger below is the one I own. I really struggled with NOT buying a gas one, but in the end I’m very pleased with it. You really only have to pull it out every few weeks so it’s not like a constant pain to drag out cords.
Here is the link for the edger: https://amzn.to/2tOFGaN