Their material is high-fired centigrade to ensure frost resistance and durability. Due to the processes used in the manufacturing of their hand-made and hand-glazed containers, all variations with respect to firing, and crackling are natural occurrences in the manufacturing process. The material on their containers consists of natural, not chemical, components, and therefore the final color of the product will vary. This process creates the unique beauty of each piece. Features Planters that must be left outside should be covered to prevent water, snow, and ice from accumulating inside the planter. Due to the processes used in the manufacturing of our hand-made and hand-glazed containers, all variations with respect to firing, color, size and crackling are not deemed to be defects but are natural occurrences in the manufacturing process. The glazes on these containers consist of natural, not chemical, components and therefore the final color of the product will vary. This process creates the unique beauty of each piece. While the high firing temperature and quality of our glazed and terra cotta containers results in a durable and frost-resistant product, we still recommend that they be stored in a frost-free covered area in winter. If left outside, water may accumulate in the container and freeze, causing the planter to crack and break. If a planter must remain outside during the winter months, they should be planted with sufficient drainage and raised up off of the ground to allow water to flow out and prevent the planter from freezing to the ground.