What the build takes
- Cedar 2x6, 8 ft×6$108
Rough-sawn western red cedar. Naturally rot-resistant with no chemical treatment, so it is safe right next to vegetables.
Let the boards acclimate a day before cutting so they settle to your yard's humidity.
- Oak dowel, 19 mm x 1 m×1$9
Hardwood pins lock the corners with zero metal - nothing to rust out and stain the cedar.
White oak or hickory both work; avoid soft poplar dowel.
Buy · Lee Valley Alt: 3/4 in stainless rod - Landscape fabric, 1 x 3 m×1$12
Optional weed barrier for the base; keeps grass from creeping up into the bed.
- Exterior screws #8 x 21/2 in (optional)×24$8
Only needed if you skip the dowel joinery and want a faster butt-jointed build.
Use coated or stainless - bright screws bleed rust down cedar within a season.
Alt: Oak dowel joinery (this plan)
- Circular sawMakita 5007MG
Any circular saw with a sharp 40-tooth blade will do; the ends just need to be square.
A cheap track/edge guide gives you glue-line-clean cuts on the wall boards.
Buy · Home Depot Alt: Hand saw + miter box - Cordless drillDeWalt DCD709
Bores the 19 mm dowel holes and drives the optional screws.
- Spade bit, 19 mmIrwin
Matches the oak dowel diameter for a snug, tap-in fit.
A brad-point bit tears out less on the exit face if you have one.
- Mallet
To seat the dowel pins without mushrooming the ends.
Alt: Dead-blow hammer
BUY LINKS MAY BE AFFILIATE LINKS — THE CREATOR MAY EARN A COMMISSION AT NO EXTRA COST TO YOU.
The build, step by step
Cut the walls
Cut the six cedar boards into four long walls at 1200 mm and four short walls at 800 mm. Square every end - the corners only pin up tight if the boards meet cleanly. Label the offcuts; the short leftovers become the corner pin blocks.
Bore the pin stacks
Stack a long and short wall at each corner and bore two 19 mm holes 100 mm deep through both boards at once. A scrap-wood doweling jig keeps the bit square so the corners pull together without twist.
Dry-assemble
Tap the oak pins through each corner stack with the mallet - no glue. The joint is designed to tighten as the filled soil pushes the walls outward against the pins, so it actually gets stronger once planted.
Site and fill
Level the ground, lay the optional landscape fabric, and set the bed. Fill in layers - coarse sticks and leaves at the bottom, then a soil-and-compost mix on top. Water each layer as you go so it settles before planting.
Safety & disclaimers
Call before you dig - hit 811 (North America) to have buried utilities located before you level or excavate the site.
- DIY projects carry inherent risk. Build at your own risk and check local garden/building codes before you start.
- Cedar sawdust is a known respiratory irritant - wear a dust mask when cutting.
- Never use pressure-treated lumber for beds growing food; its preservatives can leach into edible soil.
Questions builders ask
Why no screws or nails?
The pinned corners let the whole bed knock flat for winter storage and there is no hardware to rust and stain the cedar. The soil load keeps it tight.
What soil mix should I use?
Roughly one-third topsoil, one-third compost, one-third aeration (perlite or coarse bark). It drains well and feeds most vegetables for a season.
How long will untreated cedar last?
Western red cedar in ground contact typically lasts 8-12 years. Setting it on gravel or fabric rather than bare soil adds a few more.
