Despite the name, self watering containers do not actually water themselves. The containers are divided into two chambers. The lowermost container is a reservoir for holding water. The upper container is designed to hold the plant and soil. The two containers are separated by a screen through which the water can pass into the soil, thereby ensuring that the soil stays damp. And while the container gardener still has to put water into the watering reservoir, the amount of work that goes into caring for the container is greatly decreased.
Put on protective clothing, including gloves and goggles when working with power tools. Measure the interior length and width of the container at a level that is 4 inches from the bottom of the container.
Mark the lid of the container with the length and width measurements. Cut the lid of the container to the measured dimensions so that the lid will fit inside the container.
Stand the four pieces of PVC pipe on their ends inside the container. Space them so that they stand in each corner of the container. Drill holes throughout the lid of the container, spacing them 2 inches apart.
Drill a hole in the container 4 inches from the bottom of the container. This hole will act as a drainage hole and a point through which you will water the container.
Place the lid inside the container flush against the 4 pieces of PVC pipe. Fill the container with potting soil. Sprinkle dry granulated fertilizer onto the surface of the soil and cover the container with landscaping fabric.
Cut a small hole in the landscaping fabric. Pull back the soil and place a plant into the soil pocket. Pat the soil down around the plant to release air pockets. Replace the landscape fabric and cover with mulch. Fill a watering can with water. Insert the spout into the drain hole and fill the reservoir with water.