How to Build a Garden Box: A DIY Guide

There are many reasons why garden boxes are a great idea. They’re more ergonomically friendly, as their raised height makes them easier to work with. They also allow you to grow a garden on land that may otherwise have poor soil. Also, they look great!

Building your own garden boxes is easy, requiring just a few materials, the right tools and a little skill. In just a few hours’ time, you can have your own raised garden box ready to go, adding both function and style to your backyard space.

What You’ll Need

The dimensions of this project are for a 4’x8’ raised bed. You can make adjustments for any size you like, but keeping a width of four feet makes it manageable to access the entire garden while remaining outside the bed.

  • 2”x12”x4’ boards x 2 for the ends
  • 2”x12”x8’ boards x 2 for the sides
  • 2”x4”x4’ board for the corners
  • Wooden mallet
  • Electric drill
  • Wood screws
  • Measuring tape

A Note About Selecting the Right Type of Wood

The type of wood you choose to build your box will have an effect on how long it lasts. Pressure-treated lumber has chemicals added that prevent rotting caused by weather or moist soil. These chemicals are deemed safe for organic growing, but some people still have concerns about these products.
High-quality woods like cedar have oils that naturally resist moisture, making them a great choice. While these materials will last many years, they are a more expensive choice.

Railway ties are not recommended, as they may be treated with creosote, which is toxic.

Choose Your Location

When choosing the right spot for your garden box, you’ll want to keep your eyes open for a few different things. To start, you’ll want a fairly level ground for the garden to rest on. If there’s too much of a slope, soil can spill out. It also risks having the weight of the soil sitting unevenly, which can damage and eventually break your box.

Once you’ve found a nice, flat space, make sure that it gets adequate sunlight. The amount of sunlight you’ll want will depend on what you’re growing, but any location that’s forever shaded won’t work. Ideally, you’ll want to find a location that gets 6-7 hours of sunlight. Laying out the garden box north to south will prevent larger plants from blocking the sun from reaching smaller plants.

Finally, you’ll want to prep the area for the coming garden. If there’s grass currently growing in the desired space, either remove it or transplant it. The ground below should be well turned, going a few inches deep.

Set Your Supports

Because this box will only be a foot high, the corner supports can sit directly on the ground. If you choose to go with a higher bed, you may want to consider setting the supports a few inches into the ground for extra support.

Cut your 2”x4”x4’ into four equal lengths. Each of these will support the box at the corners. Measure out your rectangle and place a post at each one.

Install the Walls

Position your remaining boards along the outline of the rectangle. Once ready, you can begin to attach them to the support posts. Drilling pilot holes with a drill bit before driving in the screws is a great way to prevent the wood from splitting and offers a guide for the screws when you install them.
Start with the four-foot-long boards, as they’ll be easier to stand. Drive the wood screws firmly into place. Once they’re set, move on to the eight-foot boards.

Lay Your Soil

Now that your box is built, you can begin filling it with soil. Some people like to lay a weed cloth down first, to prevent unwanted growth. If you want to do so, cut the cloth slightly larger than the box so that you can staple it to the bottom edge of the raised bed.

Building your own garden box is a simple project that looks great and offers a ton of value. These plans can easily be adjusted to meet your needs, whatever size they may be. Be creative, have fun and get growing!