Winter protection for plants in Balcony containers

(Question)

These are all on 8th floor of terrace with south west facing lake Ontario. Gets very windy. Should I also mulch the pots for I insulation

(Answer)

Thank you for contacting the Toronto Master Gardeners about winter protection for the plants on your 8th floor terrace.

You can find responses to the many questions we have received on this subject by using the search box under Find it Here on the main page of our website.  The short answer to your question about whether you should mulch your pots for insulation is, yes.

Here are the key points for winterizing all plants in containers including those on balconies and terraces:

  1. Choose pots made of material that will withstand freezing temperatures such as heavy plastic, wood and fiberglass.  Certain ceramics, fired at high temperatures may also be ok but are not guaranteed to withstand harsher conditions, so may crack.  All containers must have drainage holes.
  2. Insulate around the pots themselves using styrofoam or bales of straw in order to protect plant roots within the container.
  3. Mulch the top of each plant.
  4. Keep plants well-watered up to the first frost.
  5. Move the pots to a sheltered position away from winter winds and , if possible, erect some kind of windbreak around them.
  6. Keep in mind that in addition to freezing temperatures and high winds these plants also need to be protected from thaw-freeze cycles.

Below are links to a couple of our previous responses that provide details on the key points above. Each of these responses contains links to other responses and articles that you might find  helpful.

Winterizing / Insulating Balcony/Terrace perennial gardens

Overwintering shrubs and perennials in pots

Wishing you a successful season of overwintering your plants, we hope you find this information helpful.

Nov 8, 2023