ARIANA COLLECTION by Bloem: The planter waters plants when you're not looking and helps keep your plants from drying out. Here's how: Inside the planter, at the bottom, is a hidden reservoir that holds approx. 1 in. to 3.5 in. of water (depending on planter size). The self-watering insert keeps dirt and roots above the hidden reservoir line while constantly providing healthy "greenhouse-like" moisture through the evaporation process. If you're forgetful, or you're just not home very often, self-watering containers are a must-have. They're also helpful if you're growing in an area that's not convenient to a water spigot, such as a balcony. How a self-watering planter works: the potting mix is held above the water line by a sturdy screen. The water chamber is connected by small porous channels filled with soil, which then acts as a water wick. As water is used by the plant or evaporates from the surface of the soil, capillary action draws more water up from base of planter. The soil has just the right amount of water all the time, but also maintains air pockets, which the plant roots need to stay healthy.