Introduction: Easy 4x8 Expandable Raised Bed
I have made a very successful raised bed from reclaimed wood, so I decided to share it with you! This is super easy to make, and can grow vegetables extraordinarily well.
Step 1: Measure and Cut and Prepare
You'll need a pretty simple list of cuts, which will totally vary based on your wood planking size. My wood planks were 1x4, so I decided to do 3 layers to bring the whole raised bed to a depth of 10.5 inches (1x4 is 0.5" x3.5").
Here's what I cut:
6pcs 13" 2x4 for posts
18 pcs 1x4 for siding or raised bed
To help against rotting wood, use longer lasting wood like redwood or cedar, and consider painting the inside to shed water. ( also consider the chemicals that could be in or paint or lacquer)
Quick note: If the pictures are confusing, I actually used 2pcs 2ft long planks and a extra 2x4 post on the raised bed width because I didn't have the correct wood.
Step 2: Start Making the Sides
Use two 2x4 sections to begin the side. On a flat surface, place the 2x4 parallel to each other spaced at ~4ft with the 3.5" section facing down and upwards. Layer the planking/siding on top perpendicular, spanning the 2x4. On one side, the planking should overhang the depth of the planking (fo me 0.5") in order to cover ugly corners and halfway through the other 2x4. Now screw the planks on, starting with the top(ensure its nice and straight) and work your way down to avoid slanted raised beds.Then repeat this step but add the planking to the 2x4 which you'll use the planking to meet halfway. In all, you'll have 3 parallel 2x4 posts, one on each end and one in the middle of the 4ft planking sections. Repeat for the other side.
Step 3: Widths
Now that you have two sections of the 8ft length of the planter box, you'll have to attach the 4ft planking to create the width. Best done with some help, drill the planking to the 1.5" section of the end 2x4 on the length section. Create two L sections by adding the width, then create a box by screwing them together.
*Optional: You can add a structural 2x4 between the middle 2x4 of the lengths to strengthen the raised bed walls.
*Optional: You can put a lip of planking on top of the 2x4 for a cleaner look, as well as giving some space to place tools and lean against when gardening.
Step 4: Instalation
Make sure you have properly cleared a level 4.5'x8.5' area. The best way to do this would be to mulch or tarp the ground to make sure weeds are no going to grow upwards. I designed this project to use 2x4 posts to be planted into holes on the ground. I like to notch into the dirt around where the planking sits on the ground to give a nice tight fit.
Now, fill with dirt. The best way I found is to start with a layer of cardboard, and lasagna layer mulch, compost, and fine dirt until ~4 inches from the top of the raised bed.
*Optional: if you have gopher problems, It's recommended to add a steel mesh below the cardboard layer.
Step 5: Enjoy!
Plant your newly constructed raised bed with all the greens you could want!
The easy design allows you to easily add plastic sheeting atop, as I have done for shade and wind protection, or a pvc hoop greenhouse. Whichever way, I hope you enjoy your raised bed!