How to Make a Garden Box

There are many advantages to gardening in raised beds or garden boxes. They improve control of soil quality. They allow for earlier planting in spring, extending the growing season. And they reduce problems with weeds and pests.

A garden box also has better drainage because the soil is never compacted by being walked on. Finally, gardening in a raised bed is easier on your body, with less stooping and kneeling. Here’s how to make a garden box.

Before You Make a Garden Box

Before building your garden box, here are a few things to consider:

Where Is the Best Place For Your Garden Box?

The best location gets full sun for 6 to 8 hours per day. Choose a site that is level, well-drained, and protected from strong wind. The garden will require easy access to water. Almost no location is perfect, but that’s OK. Just take the site’s limitations into account when choosing what to plant.

What Size Garden Box Do You Need?

If the raised bed is built against a fence or wall, its maximum width should be 3 feet. If it’s to be accessible from all sides, the maximum width should be 4 feet. That way, the whole bed can be reached from the sides, and there is no need to step onto the soil.

Stepping on the soil compacts it, making it less inviting for the roots of new plants. A garden box can be as long as you like but should only be 3-4 feet wide.

How High Should a Garden Box Be?

The depth of the soil depends on the crop. Greens will thrive in 5 or 6 inches of soil. Most flowers and vegetables need 10 or 12 inches for deep, strong roots. Very deep-rooted vegetables like carrots, potatoes, squash, and tomatoes will do better with 12 to 18 inches of soil.

How to Prepare the Site For a Garden Box?

Remove any vegetation down to the dirt for at least 8×8 feet. Use a shovel to loosen the ground to a depth of 6 to 10 inches. This will also help excess water to drain away from the bed. Rake the area smooth. The garden box will sit in the center of this space.

A wide, mulched walkway around the raised bed will make access easier and deter pests and weeds.

A garden box built of untreated lumber will last for several years before it deteriorates. For more durability, cedar can be used. However, raised beds can also be constructed from other materials such as sandbags or earthbags, cinder blocks, hay bales, galvanized metal stock tanks, logs, bricks, or corrugated steel.

To Make a 4×4 Garden Box From Untreated Lumber, You Will Need:

Untreated lumber: 4 1×6” boards 8 ft long
Untreated lumber: 4 2×4” boards 12 inches long
Wood screws: 2.5 or 3 inches long
Screwdriver
Drill, tape measure, T-square, and level are helpful
Ground cover (see below)
Material to fill the box – topsoil, compost, aerating material, and mulch

To Make a Garden Box, Follow These Steps

Put the ground cover under the box. Some pests, such as gophers, can be deterred by using a metal mesh under the bed. If gophers are not a problem, skip the mesh and simply lay out a thick layer of cardboard over the ground, 8 or 10 square feet, to be covered with mulch when the bed is finished. A double thickness of cardboard is a good idea, with no gaps between the pieces. Remember to remove tape and staples from the cardboard before spreading it. They won’t deteriorate, and unseen staples buried in the soil can cause injury. A cardboard or newspaper groundcover will smother weeds, prevent weed seeds from germinating, and gradually deteriorate into the soil.
Cut the 8 foot 1 x 6 boards in half, or have them cut at the lumber yard. Assemble them into 2 squares, and fasten the sides together with screws.
Center one square on the cardboard layer, and place the second square on the first. Use screws diagonally to attach the top square to the bottom.
Use the 2x4s vertically in each corner to attach the top and bottom and add stability.

The garden box is done and ready to be filled!

How to Fill a New Garden Box

For a new garden, buying bags of soil is the best way to go. Developing good garden soil is a labor of love that can take years of composting, mulching, and weeding.

However, bagged soil and compost are free of weed seeds, harmful microorganisms, and other potential problems for the garden. This finished bed will hold about 16 cubic feet of soil. A 40-lb. bag of topsoil covers .75 cubic feet, so this bed will need 21 bags.

Fill your garden bed with topsoil rather than potting soil. It’s less expensive and less airy; topsoil will settle close around the roots of new plants, bringing them water and nutrients. Mix the topsoil with well-aged compost, not with un-aged manure, which will damage plants.

Fill your garden box with a mix of about 70% topsoil, 20% compost, and 10% material such as pearlite, coconut coir, or rice hulls. These provide aeration and promote good drainage. Mix all the ingredients thoroughly as you fill the bed. The soil mixture will settle over time, so keep topping up with compost as the season advances.

Mulch Your New Garden Box

If the box is not going to be planted immediately, cover the new soil with cardboard or a thick layer of newspaper to prevent weed seeds from settling there. Spread mulch, such as wood chips or straw, on the ground cover all around the base of the garden box.

After planting, mulch the whole surface of the raised bed as well. Mulch conserves water, discourages pests, and prevents weed seeds from sprouting.

Conclusion