There are hundreds of edging ideas out there. Design ideas like fences, walls, foot edging, and hedges can be brought home by you on your camera phone as you move through your neighborhood.
Parks, city buildings, parking lots, and hospital buildings can each yield a great idea or two. Plus, there are fabulous public / private gardens worth a visit.
3 ways to ‘edge’ your garden
Here’s one border using the mighty boxwood as a hedge in this dramatic mixed planting at Butchart Gardens in Victoria, B.C.
It is a good choice to control foot traffic, especially the smaller kids or animals on a leash.
On one hand . . . go low
What is an edge swale anyhow? The short answer: a shallow channel that gathers rain water runoff from the grass on one side, and the mounded garden on the other, then routes it to avoid flooding as it reenters the soil. Really, it’s an small example of farming irrigation design. In the Northwest U.S., it’s used everywhere because of the heavy seasonal runoffs.
This is the most common type of edging used in home gardens because it’s low maintenance and low cost. Others include bricks, stack pavers, preformed curbs, or poured-in-place concrete.
On the other hand . . . size it for plant size.
Stone block small wall 
A divider can be as simple as a small stone wall between the grass or walkway & the mounded soils in the garden bed. Shown above are a raised curb with a poured wall behind it at a hospital and my stacking stone wall for a temporary retail exhibition with still-potted plantings set in the wall on boards. Nice visuals and access without feet damaging the goods.
And yet another hand . . . create a backdrop
Brick walls 
Stacked boulders
Try a low fence – or get as elaborate as a 6 ft tall brick wall. Many walls are topped with overhanging plantings when used next to a property border or divider. Great spots for contrasting colors and textures.
Sante Fe 5 ft adobe wall with plantings on both sides. Unfortunately, little color. 
Split rail or staggered board fencing is an easy spatial divider.
None of these choices have to be formal to be effective – in fact most aren’t.
They usually evolve from the height of the background feature or width of the adjacent walkway.
Some even use a stumpery as a barrier.
