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How to build a raised garden bed

Workshop Legend

Difficulty: Expert

Raised garden beds are extremely popular for growing vegetables and flowers. When designed and built well, they can look brilliant and become a real feature of your backyard.


Here’s how to build a fantastic planter-box style raised bed that you can adjust in size and height to meet your needs. The design even includes an optional seat for when you want to take a break and enjoy the garden.


Workshop community members looking for an easier project should visit How to build a simple raised garden bed

Video Tutorial


Step 1

Decide on the location for the bed. For vegetables or flowers it will need to be a sunny spot with good wind protection. Our position is beside an elevated deck area.


The techniques used to construct this bed mean that you will not require engineering-grade footings. The main posts only need to be deep enough in the ground to provide stability during construction and to stop any settling. You could build this project on a hard, level surface such as a courtyard without needing to sink footings.


Raised Garden Bed.png  1.2 Choose the location.jpg

Step 2

Set-out for the post locations and dig post holes to around 300mm deep. Measure and cut a 75mm sleeper for the centre post, concreting it in place. As ours was against an elevated deck we used a sleeper offcut as a temporary spacer to get positioning correct. Cut and position the two end posts and concrete them in place.


The posts in this project are internal (concealed) behind the boards on the external face. If your bed is to have a split height like ours and the upper and lower beds are to be of equal size, then the centre post will need to be offset from centre biasing towards the high end to allow 50mm for fitting the centre end-boards on the outside edge. All end posts will also need to be offset 50mm towards the centre to allow for end-boards.


Tip: Using a long level and clamps makes it easier to get the correct alignment and height.


2. Dig posts.jpg

Step 3

Once the three front posts are in place, add runs of uncut sleeper face-boards. Remember to check level of each before securing to posts with construction screws.


Tip: Using a drop-saw is the fastest and easiest way to ensure accurate cuts.


3.1 Add sleeper face boards.jpg  3.2 Use a drop saw.jpg


Step 4

Using the three secured posts as a guide to measure out for the opposite posts. Cut, position and concrete in the remaining three posts for the opposite face. Cut a 1000mm sleeper length for an end board, put in place aligned with lowest face board. Check level, screw in place to both posts and use this as a height guide for face boards on the opposite side. Repeat the assembly process used for the first face, cut and add face-boards to elevated section then add all end-boards on one end only.


Using a tape and level, mark a line around the inside of each bed section approximately 350mm down from the top edge. Measure along the marked lines and cut support rails from sleepers to fit. Fix in place with construction screws. You’ll also need to add small blocks as rails to the internal posts.


4. Check level before screwing in place.jpg

Step 5

The distance from side to side on top of the rails should be 1000mm (less at posts). Cut the sleeper lengths to fit as base-plates for bed. You may need to trim or rip a sleeper down to fit the last space. Position the base plates and screw to rails leaving a gap of 3- 5mm between each plate for drainage. When the first section is finished, add the end-boards as bed dividers between the high and low section before repeating the base plate process for the upper section. Once done add last external end boards.


5. Base plates for bed.jpg

Step 6

Cut drainage fabric to size as a bed liner. Make it large enough to lap up all sides and cover the sleeper joints before stapling it in place. Fill the bed with soil, add irrigation if desired and you’re ready to start planting your new garden bed.


Tip: Add a professional finish to the bed by using a hand-plane or shaper to bevel the sleeper edges.


6.1 Use drainage fabric as bed liner.jpg  6.2 Bevel the sleeper edges.jpg

Step 7

This is an optional addition, but a simple bench seat fitted to your raised garden bed will make gardening easier and give you a spot to relax.


On the bed face, mark the position for a seat supporting rail. The top of the rail should be around 350mm above ground level. Cut a 800mm length of 45 x 90mm treated pine as a support rail.


Counter-sink and pre-drill at least three holes along its length. Apply construction adhesive to rear. Position the rail against the line and check it is level before screwing in place with 100mm construction screws.


7. Seat supporting rail.jpg

Step 8

Cut two pieces of sleeper to 980mm long. For a seat 300mm deep cut or rip one piece length-ways to reduce to 100mm wide. Lay pieces flat and clamp together ensuring ends are flush. Cut two pieces of 45 x 90 pine approximately 270mm long for cleat plates, then add a 45-degree bevel to one end of each piece. Counter-sink and pre-drill at least three holes in each, apply construction adhesive to top (long side), position with square edge flush with back edge and sides of clamped sleepers. Fix in place with construction screws.


Apply a bead of construction adhesive to the top of the rail on the wall and then position the seat panel. Pre-drill through the back of the seat panel into the rail or skew-drill into face sleepers of garden bed and then fix in place with 100mm construction screws.


8.1 Seat construction.jpg  8.2 Position seat panel.jpg

Step 9

Cut lengths of decking for the side and front faces of the seat. You can butt or mitre-join these. Apply construction adhesive to the rear of the pieces and then nail or screw them in place. Cut decking for the top to 1040mm in length - this allows for approx 10mm overhang on each side. The front slat should also have a 10mm overhang. This may require the slat closest to the bed face to be ripped to size. Measure carefully and fit decking from rear to front. Apply construction adhesive and nail or screw decking down.


Add braces to add strength to your seat. Measure from the front of the underside to the bed face at a 90-degree angle. Cut two blocks of 90 x 45 treated pine to suit and then glue and screw in place around 50 to 100mm in from the edge on each side with construction screws.


9.1 Decking panels for seat face.jpg  9.2 Panels can be nailed in place.jpg

Step 10

Clean down the seat to remove any dust and dirt and then apply a coat or two of decking oil and your new bed is all done.


10.1 Apply decking oil to finish.jpg  10.2 Finished seat.jpg  10.3 Finished bed.jpg  10.4 Finished bed.jpg


This project uses treated pine. Any beds where food will be grown or where you are likely to have contact with the timber should be constructed from non-CCA treated timber. Any timber in contact with soil should also be at least H4 rated.


You should plan and build your bed to standard sizes to avoid wastage and reduce cutting. For example, sleepers come in 2.4m and 3m lengths so make your bed to a full sleeper length and the width of half a sleeper.


To build a bed the same size as ours, you will need:

  • 20 sleepers measuring 200 x 50mm x 3m
  • 4 sleepers measuring 200 x 75mm x 3m (for posts)
  • 6 quick set concrete bags (1 per post)
  • 75mm and 100mm Timber Construction Screws
  • Roll of drainage/filter matting
  • Soil, bagged or bulk
  • Exterior grade construction adhesive (optional)
  • Treated pine decking boards (optional)
  • 90 x 45mm exterior treated pine (optional)
  • 40mm ACQ safe treated pine countersunk screws (optional)
  • Water-based timber oil/stain (optional)
  • Wood Glue


  • Digging spade
  • Shovel
  • Tape measure
  • Long spirit level
  • Quick clamps
  • Drill driver
  • Large power saw or drop-saw
  • Shaper or block plane
  • Caulking gun (optional)
  • Nail gun with exterior nails (optional)
  • Paint brush (optional)


Raised Garden Bed.png

1.2 Choose the location.jpg

2. Dig posts.jpg

3.1 Add sleeper face boards.jpg

3.2 Use a drop saw.jpg

4. Check level before screwing in place.jpg

5. Base plates for bed.jpg

6.1 Use drainage fabric as bed liner.jpg

6.2 Bevel the sleeper edges.jpg

7. Seat supporting rail.jpg

8.1 Seat construction.jpg

8.2 Position seat panel.jpg

9.1 Decking panels for seat face.jpg

9.2 Panels can be nailed in place.jpg

10.1 Apply decking oil to finish.jpg

10.2 Finished seat.jpg

10.3 Finished bed.jpg

10.4 Finished bed.jpg

17 Replies
Making a Splash

That’s a very impressive raised bed - thanks for sharing! 🌿

Getting Established

Hi, we were recently trying to buy some treated pine sleepers for garden beds but two of the local bunnings stored on CCA treated one not ACQ. We were told it comes in rarely. Did you use ACQ treated pine? Any tips on where else can I source these? Thanks

Community Manager
Community Manager

Hi @KaraZorEl,


Let me tag @Adam_W for you so he is alerted to your question about timber. 


Looking forward to seeing your garden bed project progress. Please share it with the community. We have loads of clever and creative members sharing helpful information and inspiring projects on Workshop every day.




Workshop Legend

Hi @KaraZorEl , yes, it's an interesting conundrum with CCA & ACQ as technically for domestic use timber is supposed to be switching over to non-CCA. You'll find, for example, that Bunnings standard pine decking is now ACQ.
Without going to a special order the best option will be micro-treated timber as it's safe too. Look at the MicroShades product as an ACQ alternative.

Finding My Feet

This is a really nice put together raised garden bed. Just what I would love but maybe just a bit hard for a first timer. Thank you for sharing :smile:

Community Manager
Community Manager

Hi @Mystique,


We have asked @Adam_W to write us a guide for how to build a simple raised garden bed. Coming soon!  


A very warm welcome to the Workshop community. We're pleased to have you join us and trust our helpful members will help you build your confidence and skills in no time. Feel free to post anytime you need a hand with a project. 




Community Manager
Community Manager

Hi again @Mystique,


Adam has now shared his guide to building a simple raised garden bed here -


Please let us know if you need a hand with building your own. The Workshop community would be more than happy to help.


Hope all is well,




Finding My Feet


Community Manager
Community Manager

Hi @Edmund58558,

Welcome to the Workshop community. 


As Adam noted above, any garden beds where food will be grown or where you are likely to have contact with the timber should be constructed from non-CCA treated timber. Any timber in contact with soil should also be at least H4 rated.


Once you've chosen the timber you think you want to use, feel free to come back here and check with the community whether it's appropriate for your project. 


You might be interested in following the step-by-step directions in this project for your job -


Thanks for joining in the discussion. We are looking forward to seeing your new garden beds come to fruition. Feel free to post anytime you need a hand with anything.




Just Starting Out

Thanks for sharing. Certainly given me lots of ideas!



Community Manager
Community Manager

Awesome, thanks for the positive feedback @sholland. Please let us know if you need a hand with anything. We're looking forward to seeing what you can do at your place!


Welcome to the Workshop community,




Community Manager
Community Manager

For those that have constructed a new bed for growing herbs, vegies and other produce, the wonderful @Noelle has shared step-by-step advice about how to fill a raised garden bed.


Please let us know if you need a hand with anything. We're here to help.




Cultivating a Following

Impressive raised planter. I noticed you used drainage matting. I've read elsewhere to use landscape fabric. Are these the same thing?


I am building a raised vege planter box, off the ground. I want some water to drain out the bottom so the soil doesn't become waterlogged, but then I don't want to lose my soil through the bottom either. 


What do I line the bottom of the planter with?

Bunnings Team Member
Bunnings Team Member

Hi @Ritar 


Let me tag @Adam_W to make them aware of your kind words and questions. The advantage of using Geo Fabric is that it keeps the soil from draining away in the rainwater. Due to its very fine material, it only allows water to pass through. If your budget allows it, I recommend using geo fabric rather than weed mat for the bottom of your raised garden.


If you need further assistance, please let us know,




Workshop Legend

Hi @Ritar when you are lining any bed like this, and even retaining walls in the landscape, you need to line them with a suitable drainage fabric.
As @EricL said and you implied, it stops soil running out while still allowing a reasonably normal level of water and air flow.

Typical woven weed mat is not appropriate for this type of use as it tends to clog up.
The correct material goes by a lot of names - drainage fabric, landscape fabric, filter fabric, goetextile matting - but, apart from some minor differences, they are all pretty much the same in what they do.
This is the sort of stuff you're looking for. You can get it in smaller packs too.

Just Starting Out

Fantastic article - thanks! Please, what would happen if I wanted to completely fill it with soil?

Bunnings Team Member
Bunnings Team Member

Welcome to the Bunnings Workshop community @apw. It's brilliant to have you join us, and many thanks for your question about building a garden bed.

That would be fine to totally fill it. If you are using longer lengths of sleepers for the walls, you might like to have a section that goes from the front wall to the back wall screwed between them. This helps tie the longer walls together and avoids bowing. However, if you have your post spaced sufficiently, this shouldn't be an issue.

Please let me know if you have any questions.


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