If we are thinking of building a raised bed on concrete, this is a fabulous idea. It has many advantages which we will look later. We have two options here; firstly we can construct this on a concrete surface, which will make for a solid foundation and secondly we can construct a raised bed from concrete blocks which we can locate in our backgarden. Either option will work and both ideas can become worthwhile projects. If your backyard is completely concreted, you have an ideal surface for your raised bed. Select a nice level area and begin with the first course of blocks, two rows high should be sufficient as this will give your bed a depth of approx 1-2ft. The standard size of these beds is about 8-10ft x 4 ft.

Hiring a block layer or tradesman would be a good idea for this project as we need this to be a job that looks well and it also needs to be waterproof. We don’t need any excess brown coloured water seeping from the bed as it would look unsightly and could discolour your concreted surface. Before we fill this concrete raised bed we need a layer of gravel and stones at the bottom to absorb any excess water. This system ensures that the bed never dries out completely and plant roots will always reach downwards for water.

Building a raised bed from concrete blocks on your garden surface is another option. For this job I would strongly advise hiring a block layer again. The reason is similar to above. A trench needs to be dug, a base foundation made for the blocks as we could have subsidence and then the blocks are laid to make the walls of our raised bed. This method will make a sturdy sustainable structure and should last a life-time. We might consider this method expensive, but if we have any blocks lying around from a previous project, these will suffice and will help defray some of the costs.

The two above methods of raised beds are both rot and pest resistant. The other great advantage is that the blocks, which are made from concrete, will hold the heat from the mid-day sun and carry same well into the night. This extends growing and provides healthy sustainable conditions for your plants, vegetables or flowers. If we need to erect a polythene cover over our bed we have a sturdy structure for implementing this option. A trellis can easily be added to the equation as we have strong walls to support same.