Wood raised garden beds
A wooden raised bed is a classic choice in the garden, relatively inexpensive, and easy to get started with. Untreated cedar, fir, and pine are common choices for wood raised beds. Here’s how to create a 4-ft. wide, 6-ft. long, 2-ft.-tall raised bed:
Materials for a wood raised garden bed:
Keep in mind that the lengths of boards can be adjusted based on your desired bed size.
- (4) 4×4 posts cut to the desired height of your garden bed (Here we have used 21 in. tall posts)
- (6) 4-ft.-long 2×8 pieces of lumber
- (6) 6-ft.-long 2×8 pieces of lumber
- 3-in. deck screws
Choosing the right lumber
Make sure to use untreated lumber if you are building the raised bed for vegetables. Treated lumber is OK if using for flowers or ornamental plants. Try to use sustainably sourced, local or regionally produced woods to be more ecologically friendly. A FSC (Forest Stewardship Council) certification indicates a sustainable choice.
Untreated wood may last five years or so, depending on your climate. Pressure-treated wood has about twice the lifespan but some research suggests the chemicals may not be safe for vegetables. Line the inside of your wood raised bed with plastic if you’re concerned.
Extend the life of your raised bed
To help your wood raised bed have a longer life in th garden, apply a coating of raw linseed oil or tung oil to the inside bed walls to help water-proof untreated wood. Water sealants and latex paints are also okay to use, but be sure to research what chemicals are used in them to be sure they are safe for edibles. Also, don't paint just the outside walls or the wood will take up water and have no way to dry out. Wood side walls need to "breathe" to be able to dry and keep from rotting.
How to build a wood raised garden bed
Reference the exploded view illustration above and follow the simple steps outlined below to create a simple garden bed out of wood that you can easily customize to fit your needs.
Step 1. Find the right spot for your garden bed
Decide placement of your raised bed and mark with marking spray or a line of flour or sand. Leveling the ground first makes it easier to build your raised bed and keeps it in good shape longer because there’s less stress on the wood.
Step 2. Determine the height of your raised bed
Start with four 4×4 posts cut to the desired height of your raised bed. These are about 21 in. tall. It’s easiest to simply set your anchor posts on top of the soil with the frame; sinking them in the ground isn’t necessary.
Step 3. Build the wood raised garden bed frame
- Build the frame by attaching a 4-ft.-long 2×8 piece of lumber with 3-in. deck screws to the sides of two of the 4×4 posts.
- Repeat with the other 4-ft. 2×8 and two 4×4 posts.
- Next, attach the two ends with the 6-ft.-long 2×8s.
Step 4. Attach the rest of the boards
Now that your bed frame is in place, repeat step 3 two more times, stacking the 2×8s vertically.
Step 5. Fill your raised bed with soil
Next, fill the box with a mix of half regular topsoil and half compost. Use your own compost, well-aged manure, bagged compost, or bulk compost from a reliable source. Soil may settle the first season, so water it in thoroughly and give it a couple weeks before planting if you can, then top off if you need to. Now you’re ready to plant!
Reinforce the corners
If you want an even sturdier wood raised garden bed, consider fastening metal corner brackets to each corner with 3-in. deck screws to reinforce the corner seams and keep them from popping open or developing a crack where soil can escape. You can find decorative corner brackets to dress up your raised garden bed, or some that allow you to eliminate the corner post and simply fit your side wall boards into the corner bracket for quick and easy construction.