Self-watering planters have reservoirs under the soil that hold the water the plant needs. The water is drawn into the soil as necessary to provide the right amount of water at all times to the roots. Creating a small self-watering planter allows you to grow a variety of vegetable or ornamental plants in containers without worrying about them drying out during summer heat waves. They only require occasional refilling of the reservoir in order to sustain themselves.
Use an existing flower pot that doesn't have drainage holes or a bucket for the main part of the planter. Cut the bottom off a same-size planter or cut off the rim of a bucket lid so it fits inside the planter as a screen.
Drill a ½-inch hole in the center of the screen and a 1-inch hole near one side of the screen. Feed a clean cotton wick, the type sold for outdoor torches, through the ½-inch hole so half is below the screen and half is above.
Drill six ¼-inch holes in three rows near the center of the 1-inch diameter PVC pipe. The pipe should be 4 inches longer than the height of our planter. The holes provide aeration to the soil.
Slide the pipe into the 1-inch hole in the screen. Wrap a piece of landscape fabric around the section of the pipe with holes in it and secure in place with twine to prevent soil from falling into the pipe.
Fill the planter with a soil-less potting mix up to the rim. Water it from the top so the soil is evenly moist throughout.
Pour water into the PVC pipe so it fills the reservoir. Fill until the excess water overflows from the pipe.
Sow your seedling in the planter. Refill the reservoir once a week via the PVC pipe. The wick will bring water from the reservoir and into the soil.