Unless you want to do a natural edging border with a small trench, the two most popular edging options are black plastic and bullet paver. They each have pros and cons. Plastic edging is much cheaper to buy and it’s the option that most homeowners go with. The downside is that it can be damaged by a lawn mower and can crease along curves. Paver edging is more expensive but it won’t get ruined by a lawnmower. If you can afford it, paver edging is higher quality, looks better, and will last longer.