In short, a wicking bed consists of a basin of gravel with rich soil on top of it. There is a pipe set into the gravel, which bends and rises to the surface for watering. This is how you water your plants. The water settles in the gravel and is wicked up by the soil to the plants’ roots. It is very conservative with water, as it doesn’t lose as much to evaporation as surface watering.
It’s easy to make and it doesn’t take up much space. You can plant it intensively due to the richness of the soil.
You can make it any length you wish, but keep the width something you can reach from each side (like 4 feet wide). Figure out how big you want to make it and then calculate the sizes of the materials listed below.
4″ flexible drainage hose
4″ PVC elbow
4″ PVC pipe
2″ x 2″ lumber
3″ wood screws
Attach either shade cloth or greenhouse plastic to the frame, both on the sides and roof. This will keep your plants at the right temperature and free from pests. When the plants are flowering, you can lift up a part of the shade cloth to allow pollinators inside.
Your wicking bed will need very little attention. Just make sure you water it once a week, or whenever it seems like the soil is getting dry. Each time you are about to pull up a plant (like a root), make sure you have more seedlings ready to transplant, so that you can make the most of the space.
We have been so impressed with our wicking beds that we have converted almost the whole into a series of them. We only put a tall frame on some of them.
You can make them any shape and size you want, and even have flexible drainage hoses in the PVC, so all you have to do is turn on a tap.