How to build a raised garden bed

Building a raised bed

IN THIS ARTICLE:

• Clamps
• Gardening gloves
• Raised-bed soil

A raised-bed garden helps prevent soil compaction and increases drainage and aeration to allow your plants to get the nutrients they need to thrive. Additionally, a raised-bed garden can help relieve back strain, making it a good option for both you and your plants.

While constructing a raised-bed garden may seem like an intimidating task, it’s actually fairly simple to do. This article will walk you through the steps you need to take to build your first raised-bed garden.

Planning the location of your raised-bed garden

Before building your raised-bed garden, assess your property. This article outlines the steps for building a raised bed garden that is 4 x 8 feet. You need to find a level patch of ground that isn’t located in a low-lying or wet area of your yard. This section must also get a minimum of six to eight hours of sunlight each day. In the northern hemisphere, you want to plant on the southern side of your home, as this provides the best option for sunlight. 

Building the frame

Building a raised-bed garden can be done in two stages: building the frame and filling the frame.

Tools

• Clamps
• Circular saw with blade
• Drill/driver with bits
• Saw horses
• Speed square
• Tape measure
• Staple gun (optional)
• Wire cutter (optional)

Materials

• Lumber: You need 11 8-foot long 2 x 4s. While it will eventually rot, untreated wood is the preferred option for gardening. If you want to use treated wood, do your research to be sure that what you’re choosing is safe for gardens. Untreated cedar is naturally rot-resistant, but it’s also expensive.
• Deck screws: You need 96 #9 x 2 1/2-inch deck screws.  
• Hardware cloth (optional): If you need protection from burrowing rodents, you want a 4 x 8-foot section of galvanized hardware cloth with either 1/4-inch or 1/2-inch openings.

Instructions

1. Measure and cut the lumber to size. You need six 8-foot pieces for the long sides, six 3-foot, 9-inch pieces for the short sides and twelve 10 1/2-inch pieces for the posts.
2. Square up three 3-foot, 9-inch boards to make a side wall that’s 10 1/2 inches high and clamp them together so they don’t move.
3. Line up a 10 1/2-inch post at one end and clamp it in place. Drill two diagonal pilot holes (top right and bottom left, roughly 3/4-inch in from both sides) and screw in place.
4. Repeat this process to add two more posts: one at the opposite end and one in the middle for support.
5. Remove clamps.
6. Build the other side wall in the same manner (steps 2 through 5).
7. Square up three 8-foot boards to make a longer wall that is 10 1/2 inches high and clamp them together so they don’t move.
8. The three posts on the longer walls should be attached at 2-foot intervals starting 2 feet in from the end: one at 2 feet, one at 4 feet and one at 6 feet.
9. After all four walls have been built, line up a long wall on the end of a side wall, making a 90-degree angle (with the side wall being on the inside). You need an assistant to hold the walls securely in place for the next step.
10. Drill six pilot holes at the end of the long wall into the edge of the side wall. Be careful to keep these holes 3/4-inch in from the top, bottom and end of each board. Screw in place.
11. For additional support, drill three pilot holes 2 1/4 inches in from the end of the long side and drive a screw into the post.
12. Repeat steps 9 through 11 for the other three corners to complete the box.
13. (Optional) If you want added protection from burrowing rodents, use a wire cutter to cut a 4 x 8-foot section of hardware cloth and attach it to the bottom of the frame using a staple gun. Important note: If you want to grow tubers such as carrots or potatoes, you will not be able to put a bottom on this raised-bed design because it’s too shallow.

Filling the frame

Now that the frame has been built, you need to prepare the ground and fill the frame with raised-bed soil.

Tools

• Gardening gloves
• Spade
• Spading fork

Materials needed

• Raised-bed soil
• Mulch (optional)
• Drip irrigation kit (optional)

Instructions

1. Mark off a 4- x 8-foot section where you will be placing your raised-bed garden. 
2. Use a spade to remove the grass in that marked-off section.
3. Use a spading fork to loosen and aerate the top layer of soil.
4. With the help of a partner, carefully place the frame over the area that you’ve just prepared. If you used hardware cloth, that side must be on the bottom.
5. To keep the filling of your raised bed as easy as possible, use no-mix raised-bed garden soil — a 4- x 8-foot plot that’s 10 inches deep takes roughly 13 to 15 bags.
6. (Optional) Adding mulch to a raised-bed garden is optional. It can help the garden retain moisture and reduce weeds, but you only need an inch or two of mulch in a raised-bed garden. Also, mulch may prevent certain seeds from germinating, so if you’re starting from seeds, it might be best to hold off. 
7. (Optional) If you'd like to make life a little easier for yourself, instead of watering your raised garden by hand, you can install a drip irrigation kit. A drip irrigation kit delivers small amounts of water to where it’s needed most: directly to the roots. A drip irrigation kit is easy to install, and all the tools and materials needed are included with the kit. You can learn more about drip irrigation kits by clicking here.

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