It’s planting season here in the PNW and on my travels through Portland I’ve been seeing raised beds popping up like dandelions. This trend makes me very happy—the fewer lawns and more tomatoes, the better.
Wooden raised beds are neat in appearance and function well, but the expense of a raised bed constructed of cedar or teak can be a roadblock for some people wishing to grow vegetables. But it need not be. The primary purpose of a raised bed is to increase drainage and to help heat the soil. If the aesthetic of a wooden bed isn’t necessary to your landscape design, mounding soil up about 6 inches (called an “open mound” or “unconstructed bed”) or using found materials—rocks, old broken concrete, large wooden branches etc.— to create a raised bed does the job just as well. (Treated, painted or stained wood should never be used due to the danger of chemicals like arsenic leaching into your soil). Freeing yourself of lumber also allows for more interesting and sometimes more efficient bed shapes, such as a keyhole bed.
A keyhole bed takes up less room in your yard than rectangular beds that require more space for the rows between the beds. I find keyhole beds and curved beds to be a nice fit in many gardens and their shapes flow and guide the garden visitor through your yard more naturally. People tend to plant rectangular raised beds in monoculture rows — all corn in one bed, all tomatoes in another and so on. Adding a curve to your bed and treating your vegetables as ornamentals or planting them with ornamentals is both beautiful and better for pollination and pest control since the pollinators and other beneficial insects will be drawn to you food crops because they are adjacent to a wider variety of flowers. You can find a good list of ornamental plants that benefit your vegetable garden here.
I have nothing against rectangular wooden raised beds. I have five of them myself and if tall enough they can make gardening more accessible for people with mobility limitations. To me, though, the blurred lines between food production and ornamental plantings are where my garden is the most interesting. After all, it’s not what you plant in that matters, it’s what you plant — and thay can be achieved in any kind of bed.