We've all had that heartbreaking realization that some planters made of terracotta, ceramic, or other porous materials freeze and then break in the winter. These materials allow and hold water in, which then freezes and expands in the cold. Fiberglass planters are different. Harsh sunlight, cold winters, rain, ice, or snow should not affect it negatively. With the right kind of fiberglass planter, you don't have to worry about the elements cracking or breaking it down. The material will not deteriorate even when you keep it outside.