Having a raised bed in your garden has a plethora of benefits from helping those with bad backs to providing a solid base for your flowers or vegetables to grow. Purchasing or getting a professional to build a raised bed for your garden can be expensive and with costs rising across the UK, we’ve created this step-by-step guide for you to build your own DIY raised garden bed – in 5 simple steps, you’ll have your easy-to-build raised garden bed up in no time!
We also provide the answers to some commonly asked questions surrounding raised flower and vegetable beds.
What do I need to make a raised garden bed?
Once you’ve decided how big you want your new raised bed to be, you need to make sure you have a few things first…
- Rot-resistant timber (preferably softwood sleepers or reclaimed hardwood)
- Measuring tape
- Spirit level
- Rubber mallet
- Garden trowel
- Electric drill and screws
- Bricks, rubble and aggregates
- Border blend topsoil
How to make a raised bed
Step 1 – Preparation
On a level part of your lawn, dig out strips of turf which are wide enough for your planks of timber. You should only take the top layer of turf and some soil underneath – approximately 2 – 3inches.
Step 2 – Lay the timber down
Once the strips have been removed, lay the wooden sleepers in the holes and make sure they are level by using a spirit level. To achieve better accuracy, check the levels both along the length of the timber and diagonally.
You will also need to ensure the 4 corners are at right angles, as this will ensure you achieve a square or rectangular raised bed.
Step 3 – Drilling and screwing
After making sure the timber is level, tap the wood with a rubber mallet so that the corners are touching. Drill through the end of the timber at both the top and bottom and insert long, heavy-duty coach screws.
Do this for all 4 corners.
Step 4 – Adding another layer and reinforcement
The minimum depth for a raised bed should be 30cm (12inches) as flowers and vegetables require up to 60cm of soil depth to root deeply. To achieve this, add another layer of timber on top of the first set you did earlier – follow steps 2 and 3.
Top tip: to reinforce your raised bed, add a block of wood inside the corners and screw it into the parallel pieces of timber.
Step 5 – Filling your raised bed
To ensure your new raised bed has good drainage, fill the bottom with bricks, rubble, aggregates and organic material. Once this layer has been applied, fill the rest of the empty space with vegetable and fruit or border blend topsoil mixed in with compost.
Once you have filled in your raised bed, compact the soil with your hands as this will ensure your soil has a good structure for the new flowers or root vegetables you will plant.
Raised garden bed FAQs
What kind of wood should I use?
You should ideally use treated wood when constructing a raised bed as this will help prevent rotting. We recommend using cedar, pine or oak.
What should I put at the bottom of my new raised bed?
Placing broken bricks, rubble and organic matter such as bark mulch, straw and leaves will help provide a good drainage system for your raised bed.
How deep should a raised garden be?
The minimum depth for a raised bed should be 30cm (12inches) as flowers and vegetables require up to 60cm of soil depth to root deeply.
Should I line my raised flower bed with plastic?
You shouldn’t line your raised flower bed with plastic or other types of membrane as this will prevent your flowers and vegetables from rooting deep enough into the soil. For more information on laying topsoil on top of membranes, see our in-depth guide.
How many bags of topsoil do I need?
Topsoils can vary in screening sizes, therefore some topsoils may be denser than others. Generally speaking, 1 tonne of topsoil will cover 0.63 cubic metres or 22 cubic feet or 0.81 cubic yards. To find out exactly how many bags of border blend topsoil you need, see our free calculator.
What other materials can I use to construct a raised bed?
Alternatives to using timber can include; cinder blocks, concrete blocks, large natural stones and poured concrete.