How To Build A Raised Garden Box

Do you want to grow spices, vegetables or flowers but don’t have a lot of room? Learn how to build a raised garden bed or garden box!Maximize your backyard garden space and care for your plants easier with a raised bed. It can help you have better control over growing conditions, reduce soil compaction, and reduce the strain on your back from ground-level gardening. DIY-raised garden beds are great for both beginner and experienced gardeners alike!

Why Build A Garden Box?

There are many reasons to build raised garden beds. These are garden boxes that sit above the ground within a frame, typically made of wood or other materials. If you don’t have good soil on your property, you can provide better conditions for your plants.

Garden bed kits or a DIY raised bed are a great resource as plants are lifted out of the path of disturbance, and your soil will warm earlier and extend the growing season, providing gentler conditions for growing. In raised beds, fruits, veggies, and flowers can thrive while keeping your space tidy. The best part is that they are easy to make! Even if you are just getting into gardening, you are going to want some raised garden beds.

How To Build A Vegetable Garden Box

There are raised bed kits that exist, but planter boxes and the raised bed frame can be as easy as 2 x 4s on the ground or some patio blocks. Building materials don’t really matter! The garden bed design and size are up to you, but a raised garden bed that is at least 6 inches high or more gives roots enough room to grow. These DIY steps were created with a raised bed garden that is 4-foot by 6-foot by 10-1/2-inch in size made with 2 x 4 pieces of untreated lumber. Untreated lumber isn’t resistant to rot but is a good choice for beds growing edibles.

Step 1: Measure & Cut

A woman building a garden box out of a piece of wood.
Measure and mark the length of the walls of the raised bed and cut the boards. Measure and cut the 2 x 4s for corner posts to support the wall of the raised bed. These should be the same height as the garden bed wall. You can also cut and install posts along the walls for additional support.

Step 2: Attach Posts

Clamp together the boards making up each wall of the raised garden bed. Place the corner posts on top of the wallboards inline with the ends of the 6-foot walls and set back 1-1/2 inches from the ends of the shorter walls. Drill pilot holes and attach all the posts with deck screws.

Step 3: Connect

Drill pilot holes into the sides of the raised garden bed and connect them with screws to form a box frame. The posts should sit on the inside of the raised bed.

Preparing The Location

Step 1: Choose A Spot

Pick the spot for your garden bed, keeping in mind that many plants, like vegetables, need plenty of light. Place the frame where you want it positioned and mark the location for the garden bed outline with a shovel. Setting the bed on the ground and not another hard surface allows for better drainage.

Step 2: Remove Other Organic Matter

Set the frame for your planter box aside and remove the grass and other plant roots from the area. Loosen the dirt for better drainage and to promote deep root growth for your new plants.

Step 3: Add The Bottom

A garden box sitting on top of a dirt field.
Before you set your bed garden in place, you can staple a wide mesh hardware cloth to the bottom of the frame. This will create a weed barrier but still let earthworms in to perform their services to enrich the soil. Or you can use landscape fabric, newspaper or cardboard to line the bottom of your box and block weed growth from below. Make sure to thoroughly moisten the bottom medium before filling up your box. Keep in mind that weed seeds can still make their way into the bed from above and germinate, so weed growth can still be possible.

Step 4: Finishing Touches

If the wood isn’t rot-resistant, staple heavy-duty plastic along the inside walls of the raised bed before adding soil.

Adding Soil & Plants

Now that you have learned how to build a garden box, it’s time to fill your DIY raised garden bed with soil. Start with high-quality garden soil or soil mix. Fill your raised garden bed with a mixture of soil and compost to within a few inches of the top. Choose flowers or other herbs that will thrive in the location you chose. Most gardening materials and plant products have plant tags that show details on the care and conditions that the plants require. Set the plants of your choice in holes and lightly cover them with soil. Keep the soil loose around the plants to allow water to reach the roots. It’s good practice to water in the morning, as this is the best time when less water will evaporate in the sun.

What Type Of Wood Should You Use?

A garden box filled with lots of different types of plants.

The type of wood to use for your raised bed garden is your choice, but there are some options and facts to know about them:

Cedar boards or redwood are naturally water-resistant but these ones can be expensive.

Hemlock, fir or pine are able materials to be the sideboards for raised beds but don’t last very long.

Pressure-treated lumber is also an option. Pressure-treated lumber has been a controversial topic when it comes to the chemical pressure treatment to protect the wood from rot, decay and insects. The reason for this was the treatment of the wood with chromate copper arsenate (CCA) which was then banned for consumer use in 2003. The Environmental Protection Agency deemed current treatments using alkaline copper quaternary (ACQ) safe for plants and vegetables. Remember that water-based treatments like ACQ still contain fungicides and pesticides. Creosote-treated wood is not a good option for vegetable-raised beds.

Compared to untreated wood, pressure-treated lumber lasts longer and is a similar price. There are also types that are treated for ground contact specifically.

Things to do to address concerns related to it in raised beds:

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