The best way to store a planter from a planter box factory over winter is to treat it as both a container and a piece of outdoor furniture: remove everything that holds moisture, clean and dry it thoroughly, and then keep it in a dry, sheltered place off the ground. If the planter is new and unused, leave it in its original packaging or cover it to keep out dust and damp, and store it indoors or in a garage or shed rather than on wet soil.

For a used planter, start by emptying the soil, roots, and debris. Scrape off caked dirt, wash the inside and outside with mild soap and water, and rinse well. Let it dry completely in the sun or a ventilated area before storage; trapped moisture is what causes mould, rust, and cracking. Check drainage holes and clear any blockages, then inspect seams, feet, and rims for cracks. Wooden planters may need a fresh coat of material-appropriate sealant once fully dry; metal planters should have chipped paint touched up; composite and resin planters usually only need cleaning.

Indoor storage is safest. Place the planter on blocks, pallets, or a shelf so it is not in contact with a cold concrete floor. Leave space around it for air circulation, and avoid stacking heavy planters or putting weight on rims. A dry garage, shed, or basement that does not flood is ideal. Avoid sealed plastic bags or non-breathable wraps, which can trap condensation.

If the planter is too large to move, empty it completely and place it in a sheltered spot away from roof runoff. Elevate it on bricks or pressure-treated blocks, keep drainage holes open, and cover the top with a breathable cover or rigid lid that sheds rain but does not seal in moisture. Never let water collect inside, because repeated freezing and thawing is the main cause of winter damage. Check it monthly and remove snow or standing water. Avoid dragging a frozen planter.

Before spring, inspect the planter again, clean it, and repair any small damage before refilling it.