I would like to know where in Canada I could find an assortment of Begonia Tubers to plant early in the season.
The Toronto Master Gardeners are not permitted to give specific recommendations on businesses and services. Generally Canadian mail-order bulb retailers would offer at least a few different varieties of Begonia tubers for spring shipping; you will easily find their catalogues online. Perhaps you can also talk to your local nursery to see if they can order some for you. And, come late winter, check your usual big-box retailers; some carry a surprisingly wide variety of bulbs, including Begonias; you never know what you may find. We wish you the best of luck.