I did not bring in my canna lilies before the frost hit them and the foliage turned black. Is it too late to save them?
Thank-you for getting in touch with Toronto Master Gardeners with your question.
Canna lilies are beautiful plants! They are not hardy in our Ontario winters, but, it is possible to overwinter the rhizomes. The ideal time to dig them is after the first frost so your timing is ideal! The following information is from a previous answer given by a TMG on this topic:
People often refer to Canna lilies as having bulbs however they are actually rhizomes. It is not advisable to over-winter them in their planters as this can cause them to rot. The rhizomes also multiply rapidly and can therefore become choked in their container and produce weaker plants as a result. In the fall, you can dig up the rhizomes (or remove them from the planter) after the frost has killed back the foliage. Cut off the stems to about 2-3 inches from the rhizomes. Separate them and clean off the majority of the dirt. Place them in a dry place (like a garage) to allow them to cure for a couple days. Wrap them loosely in newspaper or place them in a paper bag or cardboard box and store them in a cool and dry location for the winter. Check the rhizomes periodically throughout the winter for any rot and discard any that look suspect. You can start them again indoors in early April to give them a head start for the blooming season. Do not plant more than one rhizome in your planters because again, they multiply rapidly and can be difficult to remove if they become densely packed.
Thanks and good luck,