Hello
I live in Toronto Canada.
Can Hardy Hibiscus (perennial) be grown in containers instead of in the ground?
If so approximately what size should the pots/containers be?
Thanks so much.
Thank you for contacting Toronto Master Gardeners. Hibiscus syriacus, commonly referred to as Rose of Sharon, or Perennial Winter Hardy Hibiscus can be grown in pots or containers as well as planted directly in the ground.
For growing outdoors year-round, a larger pot is preferred as more soil provides insulation for the roots during the winter. As well, a larger pot will require less frequent watering during the summer months. The size of the container you use also depends on the size of your plant. If the roots protrude from the bottom of the container or the roots appear crowded, it may be time to repot the plant to the next size up.
Don’t forget to fertilize your Hibiscus syriacus grown in containers. A balanced fertilizer is needed to ensure your plant will bloom as potting soil does not have all the required nutrients. Start with a slow-release flowering fertilizer mixed in with the potting soil when you plant your Rose of Sharon.
For your Rose of Sharon to successfully survive through the winter in a container, it’s important to provide winter protection. This involves protecting your container from wind and/or moving it to a warmer location in your garden. Adding a layer of insulation around your plant (leaves, mulch, straw or even bubble wrap) is beneficial for survival of your Hibiscus syriacus in our climate.
Refer also to Winterizing Potted Rose of Sharon
Hibiscus rosa-sinensis, or Tropical Hibiscus, can also be grown in the garden or in a container outdoors in the summer. However, these plants are not winter hardy in an Ontario garden so must be taken indoors before the first frost. The Chicago Botanic Garden has additional information on Overwintering Hibiscus