Evergreen 6-inch Bird Olla Terra Cotta Irrigation Jar Never worry about dehydrated plants with this contemporary self-watering system Made of natural, unglazed terra cotta with decorative ceramic topper Bury near roots of plants and fill with water Refill every 7-9 days; topper includes dipstick for measuring water level Measures 3.5 x 3.5 x 8.75 inches