Channel your inner MacGyver and make your own time-released watering system with a soda bottle and pantyhose. Lifehackery explains how to make the contraption:

• Get an empty plastic bottle—single serving for small plants, 2-liter for large plants. You must have the screw-top cap, as well.
• Cut the bottom of the bottle off so that it resembles a funnel.
• Poke a few holes into the cap with a nail or drill.
• Cut a square of panty hose and put it over the opening of the bottle.
• Screw the cap on to hold the pantyhose square in place. This acts as a filter to keep dirt from getting into the holes.
• Now bury the bottom of the bottle—the part with the cap—into the pot, and fill it with water. The small holes will enable a steady drip into the plant, ensuring it is never under- or over-watered.

Photo CC 2.0, five blondes