Planters to store in an indoor sheltered place for the winter months:
- Terra cotta: there is a 100% guarantee that moisture from any source will increase the likelihood that terra cotta will crack. If not, my experience has proven that even though a pot may make it through the winter, the terra cotta will start to flake, especially around the rim. Ultimately, the pots do crack.
- Glass: if you have container gardening pots made from glass, bring them inside, too. Though glass will not break from water penetrating the container itself, it will most likely break if it contains very soggy soil. The soil will expand as it freezes solid. The same is true of even the best ceramic containers, but it moves toward "less likely" as the degree of vitrification increases.
- Glazed pots (exterior only glazed): same as terra cotta.
- Glazed pots (interior and exterior glazed): these are not as likely to break in the winter. But, you're gambling if you've got them planted and left outside.
Me … I'd bring them in for the winter, to be on the safe side. If you do leave them out, don't water very often, if at all. There is usually enough natural precipitation for the plants. Plus, you're not adding additional water which helps the soil expand during a freeze, which then helps increase the chances of a pot breaking.
Container gardening planters that can withstand the coldest temperatures:
What type of planters will give you 12 months of service?
- Styrofoam
- Plastic
- Polyurethane
- Fiberglass
- Wood
- Hypertufa
- Concrete
These kinds of container gardening pots are tough and withstand harsh winter temperatures. Because they can be left outside, you can plant cold hardy plants in them, allowing you to extend your growing season. Plus, you'll be adding some visual interest to the outdoors during what is normally some dreary months for most of us.
Additional Ideas To Safeguard Planters
That Cannot Be Put In A Safe Place
**Note: I cannot guarantee that a freeze-vulnerable pot will make it through the winter using one of these suggestions, however pass these ideas along, as other gardeners have used these methods with some success:
- Wrapping pot with bubble wrap
- Mounding/covering pot with leaves or straw
- Sinking the pot in a larger container
- Placing the pot in a spot with a warmer microclimate (e.g. against a wall)
