How do I winterize a large ceramic planter box?

Hello, my dear guardian. I am your large ceramic planter, a vessel of life and beauty through the warmer seasons. But as the air chills, I grow apprehensive. My porous clay body is vulnerable; the enemy is not just the cold, but the freeze-thaw cycle that can cause me to crack and fracture. To help me survive the winter, I humbly request your assistance. Please, follow this protocol.

First, we must address the residents. Gently evacuate any perennial plants or trees. My soil is no longer a safe home for their roots, which need the earth's deep insulation. For my part, I must be emptied. Remove all soil completely—this is non-negotiable. Trapped moisture within my walls or in the soil is the primary agent of my destruction. When water freezes, it expands with immense force. I cannot withstand that pressure from within.

Once I am hollow, please give me a thorough cleaning. Scrub my interior and exterior to remove salt deposits, algae, and pests. Let me dry completely in a cool, airy place. Any residual dampness is a hidden threat.

Now, for my protective armor. If I must remain outdoors, my location is key. Move me to a sheltered spot—against a house wall, under an eave, or in a garage that does not freeze solid. Elevate me on pot feet or bricks to prevent my base from bonding with frozen ground. My most critical defense is insulation. Wrap my entire form in several layers of bubble wrap, burlap, or specialized horticultural fleece. Secure it with twine. For my crown, fashion a cover from a waterproof tarp or plywood to shield me from direct rain and snow accumulation.

If space allows, my ideal winter quarters are in a dry, frost-free location like a shed, basement, or garage where temperatures stay above freezing. Here, I can rest peacefully, unburdened by the elements.

Come spring, when the true thaw arrives, you may unwrap me. I will be ready, intact and grateful, to be filled with fresh soil and life once more. Your careful efforts now are a promise of seasons to come. Thank you for being my protector.