This self-contained system lets you grow three healthy plants on any windowsill. The trough accommodates three 4" pots — perfect for a trio of your favorite herbs. A terra cotta disk in each planter cavity wicks water to plant roots on demand, so you don't have to worry about watering so much. And because it's translucent, you'll always know when you need to add more water via the easy-fill spout. Planter cups can be removed for cleaning.