Bloem Fiskars 12 Inch Ariana Planter with Self-Watering Grid, Thyme Green (20-56412) Open diameter of Self Watering Planter is 11.50 inch Bell-shaped silhouette design with internal drainage reservoir Self-watering disk helps prevent damaging root rot and helps allow oxygen to easily access plant roots Excellent drainage reservoir to trap water and keep it away from plants roots Product Dimensions: 11.50 x 11.50 x 10.28