Building a Raised Garden
A raised garden bed is an excellent way to grow plants, especially if you are new to gardening. The raised bed has many benefits that help take the guesswork out of your gardening projects. A raised garden bed lifts your plants up to a height that makes planting, inspecting, and caring for your plants easier. It allows you to better control the nutrition of the soil by creating a barrier between the bed and the natural soil. A raised bed allows you to plant earlier in the spring, because the sun warms the bed faster than the ground around it. Hardware cloth installed at the bottom of the bed protects your plants from burrowing animals and PVC posts make netting and tenting easy for pest, temperature and moisture protection. And, a raised bed provides drainage, protecting your plants from natural or human-induced overwatering. Building a raised garden bed is fairly simple, and should not take longer than one weekend.
Garden beds can be a variety of sizes. The width of the bed should be no more than four feet so you can reach your plants from both sides. The length can be as large as you like, but smaller beds grant you greater access to your plants. The depth should be between ten inches and three feet. Beyond these guidelines, a garden bed can be a wide variety of shapes, sizes and materials, and, in addition to making gardening easier, can add as much character to your yard as the plants themselves.
Raised garden beds are available as kits that include everything you need to easily assemble a raised garden bed (Backyard Gear® Raised Garden Bed, 268-3760). Various sizes and styles give you plenty of options to choose from. You can also build your own raised garden from scratch using several different materials, such as lumber or concrete block, or even repurposed materials such as basins or bathtubs. For garden beds built from scratch, lumber is the most common material because building with wood is fast and easy. Concrete edgers are another material that is both easy to work with and inexpensive.
To build a simple wooden garden bed: These directions will work for most bed sizes and lumber sizes 2" x 4" to 2" x 10". Calculate your material needs based on the bed size you are building.
12 boards in cedar, redwood, or non-toxic treated wood (6 for length and 6 for width of the bed)
4 (2" x 2") wooden posts - each should be the same length as the total height of the completed box
Gravel - enough to fill bed three inches deep
Landscape fabric - enough for one layer inside the bed
Top soil - enough to fill bed
Wood screws - stainless steel or galvanized
Optional: hardware cloth - enough for one layer inside the bed
Optional to create cover supports: 4x one-foot pieces of PVC pipe, 1-in. diameter; 2x six-foot pieces of flexible PVC tubing, 1/2-in. diameter; 8x pipe straps
- Purchase your materials. Make sure you use an untreated wood such as cedar or redwood to prevent toxins from entering the soil (other types of untreated wood will rot quickly), or consult with the lumber yard to choose a treated lumber that is approved for use around plants and food.
Build your frame on a sturdy, level surface. Place four boards (two long and two short) upright and position them so each board bumps up to the next in a clockwise layout. Secure boards with wood screws, using your framing square to ensure perfectly square angles. Add support posts inside each corner and secure the frame to the posts using long wood screws. For the second layer of the frame, position boards counter-clockwise so the pattern runs opposite to the first. Place over the first frame and secure to the posts. The third frame should again run clockwise, counter to the previous layer. Again, secure the frame to the posts with long wood screws.
Optional: Attach 2 one-foot PVC pipes vertically inside the long sides of the frame, equal distances from each end. Once your garden bed is planted, insert the 1/2-in. tubing into the 1-in. PVC pipe and bend the tubing over to the pipe across the bed. The arched tubing will support protective covers such as netting or plastic.
- Choose the site of your garden bed. Situate your bed to run north-south for maximum sun exposure. Mark the external dimensions of your frame on the ground. Then, dig out the marked area to a depth of three inches (if the ground is sloped, you will need to level it out first).
- Fill your excavated area with two inches of gravel. This will provide a sturdy base, facilitate drainage, and protect your wood from rotting. Level the gravel.
- Place your frame in the hole. Check that the whole frame is touching the gravel and is level in each direction. If not, add or remove gravel.
- Lay down the hardware cloth over the gravel. This is optional, but will prevent underground animals from coming up under the bed to eat your plants. Add another one to two inches of gravel inside the frame. This will help hold the frame in place and provide additional drainage.
- Lay down landscape fabric, which prevents weed growth and reduces exchange between the natural soil and soil in the bed.
- Add top soil, tamping lightly every six inches. Fill to within three inches of the top of the bed and you are ready to start planting!
In one weekend, you can create a raised garden bed that allows you to plant early, water appropriately, protect your plants, and save yourself backaches for the entire growing season. Visit your local Menards® to get all the materials and expertise you need!