How to build a raised garden bed

Herb wooden planterHerb wooden planterHerb wooden planterHerb wooden planter

Raised beds are perfect for growing flowers and plants, as well as fruits and vegetables. For ease, why not buy a pre-made raised bed here? But if you’d prefer to make your own, it’s a simple job suitable for any DIYer.

This guide takes you through the process. It lists the materials and tools you’ll need and gives you a step-by-step guide on how to build raised garden beds.

Follow the step-by-step instructions below to make a 2.4 x 1.2m raised bed using timber planks. Adjust the plank lengths accordingly if you need to make a smaller or larger bed.

Step 1: Choose your location

The ideal place to locate a raised garden bed is an open area with plenty of sunshine and good drainage. Placing it near a hedge is good for airflow, but make sure there are no overhanging tree branches that will stop rainwater from hitting it. 

Step 2: Measure and mark the area

Use a tape measure to plot the area for your raised bed. It will be 2.4m x 1.2m. Mark the four corners with a wooden stake and tie string between them.

Step 3: Cut the timber

Carefully measure your lengths of timber. You’ll need two 2.4m lengths and two 1.2m lengths. Place them on a workbench and cut them to size using a hand or mitre saw. While cutting, take safety precautions, such as wearing safety goggles, a dust mask, and gloves.

Step 4: Assembly

Once the timber has been prepared, lay the four planks flat on the ground, in their position, with their inner corners touching.

Next, stand one of the long planks on its side. Then, using a rubber mallet, hammer a piece of rebar a few inches into the ground one foot from each end of the plank to support it. Repeat the process for the short sides, using one rebar in the centre of each. And then, put the other long plank into position in the same way.

Once all the planks are in position, reinforce the frame by hammering the rebars into the ground, so only 6-10 inches are showing.

  • Long sides: hammer in the two rebars already in place, then add two extra rebars 2ft apart.
  • Short sides: hammer in two pieces of rebar a foot from either end, then remove the one you placed in the centre. 
Building a raised bed

Step 5: Prepare for planting

As the raised bed will be subject to all weather conditions, we recommend painting it with wood stain, oil, varnish, or preservative before filling it. Also, line the inside with landscaping fabric, using a staple gun to attach it to the wood.

Next, spread a layer of stones or coarse gravel in the bottom to help with drainage, then fill it with a suitable compost, depending on what you plan to grow.

Your raised bed is now ready for planting!

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How to build raised beds with sleepers

Railway sleepers are another popular material for building raised beds.

First, cut them to length using a circular saw, then place them on the ground, building them up to two or three layers to get your preferred height. Then, secure the sleepers to each other using stainless steel timber screws. You can then paint, line, and fill the bed as described in step 5 above. 

How to build raised beds from decking

If you’ve got excess timber decking left over from a project, you can also use it to construct a raised bed. Choose your size depending on the lengths of decking you have. As deck boards are narrow, you’ll need to build up two layers to raise the height of the sides.

First, cut the decking to size and build the first layer by butting up the ends and screwing them together using deck screws. Then do the same with the second layer.

Next, place the two frames into position, one on top of the other, put an offcut of wooden batten in each corner and screw both parts of the frame to them. Finally, line and fill the bed as described in step 5 above. 

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  • When choosing wood, look for untreated timber that’s safe for growing plants. Avoid using pressure-treated wood, as it may contain harmful chemicals.
  • Make sure the raised bed is level to prevent uneven water distribution. Use a spirit level to check.
  • Consider adding a drip irrigation system to make watering easier.
  • To extend the growing season, consider adding a cover or hoop house to protect the plants from cold weather.

Safety first

When cutting wood, always protect yourself from flying debris, sawdust, and splinters by wearing safety goggles, a dust mask, and gloves.


To help with drainage, put stones or coarse gravel on the bottom of a raised bed.

A raised bed should be at least 20cm deep. However, the ideal depth will depend on what you’re growing. For example, root vegetables need at least 60cm.

Hardwoods are best for raised beds because they are naturally weather resistant. However, you can also use other untreated woods, decking or railway sleepers. Avoid pressure-treated wood as it contains chemicals that will kill plants.

You can line a raised bed with landscaping fabric to increase durability. However, it’s not a necessity.

We hope we’ve given you the confidence to build your own raised plant bed. But if you’re not ready for that yet, take a look at our ready-made raised bed range.

Why not browse our Gardening Range to see what else you can do to make the most of your garden this summer.