A raised bed garden can mean many things! In general, though, it’s when a planting bed sits on top of your existing soil. It can be anywhere from just a few inches tall to waist-high (or higher), and can be made of many different materials. Usually, there’s room left around the outside of each bed so you can walk around it (not in it), which allows the soil to stay loose and fluffy instead of compacted. That’s important, since roots grow best when there's room for air and water to move easily through the soil.
Most raised beds have frames, but what that frame is made of is entirely up to you. Traditional raised bed frames are usually wood or sturdy plastic, but they can also be made with stones, cinder blocks, bricks, patio pavers, broken concrete pieces (from that recent sidewalk renovation), corrugated metal, straw bales, you get the picture. In other words, you can create one to match your own style and landscape, using purchased or reclaimed materials. You don’t even have to do much in the way of building if you don’t want to, as raised beds also come in kits. (Intrigued? Check out our customized Raised Garden Bed Kits.
Whatever it’s made of, the ideal raised bed is narrow enough (usually 4 feet or less) that you can reach into the center from either side, though it can be whatever length you want. Beds can be different depths, too, and the depth you choose depends on what you want to grow—for example, deep-rooted plants like miniature fruit trees and tomatoes need more soil than shallow-rooted plants like lettuce and pansies. Raised beds can also be elevated on legs, so you don’t have to stoop to care for your plants.