Each ceramic Plant Nanny Stake is specially designed to release just the right amount of moisture into the soil. You create the water reservoir by filling an empty wine, water or soda bottle with water and attaching the included, drip-free, threaded adaptor. As the soil begins to dry, the device slowly releases more water (through gravity/diffusion). Plus, by using clear bottles, you can easily see when its time to add more water. Perfect for flowers, plants or veggies.