Many gardeners who are interested in making raised beds have asked; what is the best material to use for framing the garden beds? My preference is to use nothing as a frame for the beds, but if you insist there are a number of materials that work well when making raised beds.
The most popular choice has always been to use wood timbers or lumber. Wood lends a natural appearance, and while not permanent, will last a long time. There are mixed reports regarding the safety of using treated lumber, so I would play it safe and avoid using wood that’s been treated or coated with chemicals as a border for an edible garden.
Another popular option is to use stone, pavers, concrete blocks, or even bricks. All can be used to create a more permanent frame for your raised beds. You’ll have to determine whether the appearance of these materials will suit your taste and mesh with the rest of your landscape.
Relatively new on the scene are the plastic and composite products designed to look and handle like wood. They can be employed in the construction of raised garden beds and will not rot as a result of ground contact.
As I mentioned earlier, when making raised beds, I don’t use anything around the perimeter of the garden bed. I prefer the simplicity and appearance without a border, not to mention that it’s free and doesn’t require ongoing maintenance or replacement.
The raised beds will hold their shape just fine without edging to contain the soil. All that’s required is to taper the sides of the garden beds to provide a sloped grade and crown over the surface of the growing area.
So regardless of whether you frame or don’t frame them, making raised beds is one of the best things you can do to increase productivity and improve the overall appearance of your garden. You’ll also discover that using raised beds can reduce the amount of time and effort required to prepare and maintain your garden.