Self-Watering Wicks and Pots
When one thinks "self-watering," two different systems usually come to mind - those involving wicks, and those involving special pots:
Wicks come in two primary configurations - those that are pushed into the top of the plant, and those that are threaded through the drainage hole. Top wick systems are used a lot by "vacation feeders," whereas bottom wicks, or sub-irrigation systems, must be set up when the plant is first introduced into the pot. In both cases, the wick is generally composed of a thick, fibrous material (such as cotton cord), and set into a container full of water. Capillary action draws the water into the soil as the plant needs it.
Self-watering pots are another excellent way to keep constant moisture on moisture-loving plants. These systems usually include a pot with a reservoir for water in the base. Capillary action and/or evaporation draw water into the soil, providing the plants with even watering without the dangers of fertilizer salt build-up or root rot. You can buy either pre-built self-watering containers, or a reservoir to put in the bottom of a standard container to create your own self-watering pot.