How to Build DIY Raised Garden Beds (2024)

FAQs

What kind of wood should be used for raised beds? ›

Certain types of wood like cedar, redwood, and hemlock are more resistant to rot and decay than others. Cedar is naturally resistant to rot and pests thanks to something called tannins. That makes cedar a timber that will last a long time.

On average, a DIY raised bed constructed from wood will cost $25 to $50 per square foot. To have a wooden raised bed constructed and installed for you, budget for at least $100 per square foot. (Find a kitchen garden company in your area.)

Cardboard and Wood Chips: Layering cardboard at the bottom of your raised bed is an effective, cost-efficient way to suppress weeds. It eventually breaks down, enriching the soil with carbon. Wood chips can be added on top of the cardboard as an additional layer for weed control and moisture retention.

Raised beds made of cinder blocks or concrete blocks

Cinder blocks and concrete blocks are very inexpensive (typically $2 to $3 a piece at home improvement centers), and they make it really easy to build the outline of a raised garden bed.

He stated in a bulletin titled, Treated Wood in Raised Bed Gardening, “Scientific evidence and data have shown that using pressure treated wood for raised bed or box gardening is safe to adults and children in terms of the plants grown and used in these containers.” He further explains, “All chemicals in consumer ...

While pressure-treated wood is resistant to decay and insect damage, it's not recommended for use in vegetable planter boxes. The chemicals used to treat the wood, such as chromated copper arsenate (CCA), can leach into the soil and be absorbed by plants, posing a risk to human health.

The minimum required depth depends on the plant. But on average, a raised garden bed should accommodate about 20 inches of soil for the roots of flowers and vegetables.

Planter bottoms usually are slatted, with some type of semi-permeable cloth barrier which permits drainage. Raised beds, however, do not have bottoms; they are open to the ground, which offers the benefit of permitting plant roots to go further into the ground for available nutrients.

Use lumber that's at least 2″ thick. Many beds are built of 2x6s, because a 6″ deep bed will grow nearly anything except carrots and parsnips. At Spotts, we use 2x8s because we like that extra depth. The easiest way to make a raised bed is just to screw some 2x6s together to make a square.

It acts as a physical barrier to block out pernicious weeds. Usually, 2 – 3 layers of cardboard will suffice, though you may want layers in more weed-prone areas. The damp environment created by the cardboard is conducive to earthworms and other beneficial soil microorganisms.

Do you put landscape fabric under raised beds? ›

Depending on your budget and gardening goals, you can line the bottom of your raised garden beds with wide-mesh hardware cloth, stainless steel mesh, landscape fabric, burlap sack, or newspaper/cardboard.

For a 4x8-foot raised bed with a 6” height, using Mel's Mix: about 5 cubic feet each of compost, peat moss, and vermiculite is needed. It usually takes about two to three bags of purchased fertile mix (1.5 cubic feet each) to cover the bed surface to a depth of 2 inches.

Most garden vegetables will grow well in raised beds. Try growing lettuce, greens, radishes, and strawberries. Bush type vegetables, such as tomatoes, cucumbers, and beans also do well in raised beds. You can install trellises for vegetables that need support, like some tomatoes and beans.

Moisture-loving plants that do well in raised garden beds include cardinal flowers, sedges, and monkshood. In a dry spot, try Russian sage, prairie plants (coreopsis, false indigo, big bluestem), Mediterranean herbs (rosemary, lavender), or succulents (including sedums and echeverias).

What should you put at the bottom of a raised garden bed? Cinder or concrete blocks are an inexpensive and popular material used to build a foundation for a raised garden bed.

Avoid using older types of wood treatments such as CCA, creosote, and Penta-treated lumber. Research from Oregon State University showed that pressure-treated lumber does increase soil copper concentrations by a minor amount, but only within 1 inch of the raised-bed edge.

Use lumber that's at least 2″ thick. Many beds are built of 2x6s, because a 6″ deep bed will grow nearly anything except carrots and parsnips. At Spotts, we use 2x8s because we like that extra depth. The easiest way to make a raised bed is just to screw some 2x6s together to make a square.

Raised garden beds can be constructed from a variety of safe and sustainable materials. Cedar or redwood are two great options for wood as they are naturally rot-resistant and won't leach harmful chemicals into the soil.

Building your own wood raised beds is often the most cost-effective way to get set up and growing. My favorite wood to use is untreated cedar. It's more expensive than something like pine, but it will last a lot longer. I try to avoid treated wood because they used to use some really toxic stuff to preserve each board.