Wicking beds were invented by Coin Austin who is an Australian. It has a unique water reservoir that is underneath the soil bed. The soil is sitting on a layer of stones and a permeable membrane such as a geotextile is added between the stones and the soil. This helps transfer the water from the reservoir to the soil and also ensures that the soil doesn’t wash down.
When you are starting out as a beginner, you need to understand that wicking beds don’t need a lot of water. They need to be watered less often because of the water reservoir that is connected to the raised bed. And you will be able to control the growth of weeds through careful weeding. This will cut down a lot of maintenance that you will need to carry out. And you don’t need to worry about not having sufficient space for gardening. You can build a wicking bed anywhere. It can take some time to install it properly. There are also commercially available wicking beds that you can use which can be very easy. And you need to understand that going for a wicking bed is going to be costly initially when compared to planting an in-ground garden. But it will serve you well over time and you will be able to save water and also money in the long run.
However, there are some materials that you will need to purchase especially for the wicking bed such as lining and PVC pipes. You can try to see whether there are any materials you have at the moment that can be used instead. And try to stick to a wicking bed design that is tried and tested. The depth of the soil layer should be 25cm to 30cm as this is the maximum you can go and still ensure the roots are able to draw water from the reservoir easily. If you are planning to go for a higher depth, you will need to choose plants that have deep roots. If you are building a smaller wicking bed, you can simply get a waterproof container. For larger applications, you can use a raised bed that has a thick plastic liner creating the reservoir. When using a container, it should be about 60cm high so that equal depth is provided for the reservoir and the soil.
You should also have a drain pipe installed so that excess water can drain out and allow you to maintain the water at a 30cm depth. There should be stones added to the bottom part of the bed that has the reservoir. This creates a solid base for the soil to sit on. This should then be covered with a permeable sheet or a geotextile so that the soil doesn’t get mixed making it muddy. Make sure that you add vermicompost to the soil layer to improve the growth of your plants. There are many tutorials online about how to build a wicking bed and there are wicking beds that you can buy that are made of steel or other material which will be easy to bring home and fill with the required media.