Bloem Ariana Self Watering Planter 12" Pebble Stone. The Ariana planter waters 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"-3.5" water (depending on planter size). This 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.