That's a great question! Keeping outdoor trash cans from becoming brittle in the cold is a common struggle. The plasticizers that keep the plastic flexible can leach out or stop working in freezing temps, making the material stiff and prone to cracks. Here are some natural, practical steps you can take.
First, consider the material itself. If you're buying a new can, look for ones labeled for all-weather or extreme cold. Polyethylene resins often handle temperature swings better than others. For your existing bin, gentle handling is key. Avoid hitting it or trying to bend it when it's frozen solid. Try to empty it when it's lighter to prevent stress cracks.
A good protective product can make a big difference. Applying a UV protectant spray or a plastic restorer/conditioner in the late fall creates a barrier. These products help seal the surface, slowing moisture loss and protecting against UV rays, which also degrade plastic. You can find options at auto or hardware stores.
Where you place the bin matters. If possible, move it to a more sheltered spot, like against a south-facing wall that gets winter sun, or into an unheated garage or shed. Even a simple windbreak can moderate the temperature. Using a bin with wheels makes this relocation much easier.
Finally, think about your usage. Don't pour hot liquids or ashes directly into the bin in winter, as the extreme temperature shock can cause micro-fractures. Also, consider using a slightly smaller, secondary bin liner; if it freezes solid, it's easier to remove than a heavy, fused block of trash and ice.
With a little preventative care, your trash cans can survive many winters without turning into a cracked, brittle mess. A bit of foresight in the fall saves you from a messy cleanup come spring!