Raised garden bed

How to Build a Raised Bed

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
  • Compost

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.

Are raised based beds good for wildflowers?

Raised beds are perfect for a range of flowers, plants and so much more! See this guide on how to cultivate a wildflower garden!

About the Author

alsoils tractor landscaping service


The Alsoils Team

For more than three decades, Alsoils has been a trusted name in delivering superior soil, compost products and offering landscaping services. Based in Hampshire, Alsoils caters to a diverse clientele, including both homeowners and businesses. Our team are experts in all things gardening, so you can be sure you get the very best advice for topsoil, compost, manure and so much more!

Based on 14 reviews
Mark Belshaw
Mark Belshaw
Ordered 2 bulk bags of manure on Wednesday, late afternoon and all was delivered by Friday lunch time. Great quality product and excellent delivery turnaround.
Charles Smith
Charles Smith
Excellent, from order to delivery. 10 tonnes of loose load top soil delivered within a few days. Best price and the 10mm screened soil is great quality. Thank you
Lesley Barry
Lesley Barry
Excellent product ordered 4 bags of top soil the driver was so accommodating as we have a very long driveway. The customer sevice was excellent. Thank you.
David Robberts
David Robberts
Excellent product at a sensible price from a local supplier. Staff are friendly and willing to help: I asked if just one bag of topsoil could be delivered quickly and it arrived next day! Great service.
Mark Hibberd
Mark Hibberd
Smooth execution of the transaction and delivery. Very helpful phone call and conversation. Ordered three bags of Border Blend topsoil. Paid by Paypal. They delivered, on the specified date, carefully, exactly where I wanted the bags placed. All in all, a very pleasing purchase. The topsoil was excellent and had been very carefully prepared. No lumps. Would definitely recommend and I will use again. Everyone I spoke to was nice and helpful.
David Stamp
David Stamp
Ordered topsoil on Tuesday came by Friday at the exact time quoted. Was WAY cheaper than anywhere else (by about £15 per bag) and was dropped off via a crane on back of the lorry, not by pallet which most of the other places use. Soil was fine and dry. Brilliant !