How do I winterize a concrete planter box to prevent cracking?

As a concrete planter box, I have a proud, solid personality. I stand firm in your garden through sun and rain, but winter is my true test. When water seeps into my tiny pores and freezes, it expands with a force that can split me apart. I don’t want to be a broken relic in spring. So here is how we can work together to keep me whole.

First, clean me thoroughly before the first frost. Sweep out old soil, leaves, and debris from my interior. Dirt holds moisture against my walls, and that is my greatest enemy. I am happiest when I am dry inside and out.

Second, seal me with a breathable concrete sealer. I need a waterproof barrier that still lets trapped vapor escape—otherwise I might blister. I prefer a silane-siloxane sealer applied with a brush or spray. Wait for a dry day above 50°F so I can absorb it properly.

Third, improve my drainage. If I am a direct-contact planter (without feet), lift me off the ground using small stones or pot feet. For the soil inside, mix coarse sand or perlite into the potting mix to prevent water from pooling. If you leave me empty over winter, tilt me slightly so rainwater runs off instead of sitting inside.

Fourth, insulate me from extreme cold. Wrap me with burlap or horticultural bubble wrap during deep freezes. I do not like being left exposed to freezing winds for days. If I am large and heavy, consider moving me to a sheltered spot against a house wall or into an unheated garage.

Finally, stop watering me in late fall. I am not thirsty during dormancy. When the forecast predicts a freeze, check that my soil is completely dry. Wet soil is what makes me crack.

I have survived many winters by following this routine. Remember: dry inside, sealed outside, and lifted off the ground. Love me with winter care, and I will greet you with a perfect, unbroken smile next spring.