Many versions of self watering containers, also known as self watering grow boxes, self watering pots, and self watering planters are sold online, but you can make them yourself for a fraction of the cost out of some easy to find items.
Gardener's Supply Company: Standing Garden No Bending, No Weeding Standing Garden is Self-Watering, Too! Elevated garden is easy to plant, tend and harvest. Grow a garden in any sunny spot! Water reservoir keeps plants lush and productive Shown with casters, sold separately $149.00