Will my flower pots freeze and crack in the winter?
This is one of the most common questions we get from people when they are buying flower pots, especially in the fall. The answer is that they can, but there are ways to prevent it from happening.
The main reason glazed ceramic pots crack in the winter time is that they don’t drain properly and water fills up the pot, freezes, expands and the pot cracks, you can see an example of this above. Drainage holes can become clogged by sitting on a flat surface that blocks water from draining. It is also possible for soil to fill the hole & freeze thereby blocking water from draining.
One of the best ways of preventing your pots from freezing and breaking is to use Pot Feet. Pot feet come in a variety of shapes, sizes and colors, but the purpose is the same, to raise the pot up off of the surface and allow water to drain out freely.
You can also increase drainage with the use of a layer of gravel or Styrofoam peanuts in the bottom of the pot before you put the potting soil in. This provides an area for water to drain through, while preventing the soil from clogging the drain holes. Some people cover the drain hole with pottery shards to prevent soil from clogging it as well. In the case of terra cotta pottery, moisture can be absorbed by the pottery itself and then freeze and cause the pot to shatter. If you want to protect terra cotta, the best way would be to either seal it or bring it in to a protected area for the winter.