We live in Etobicoke. The iris did not produce any buds in the spring but I noticed a stem and 3 buds about 4 weeks ago.
What can we do to make this iris bloom in the spring?
It can be very disappointing if plants do not perform as expected. You did not state if it is a newly planted iris or an older already established plant or what type of iris it is.
If your iris is newly planted, you may need some patience, as iris may not bloom in their first spring. To ensure iris bloom, it is important that they are properly planted and get good care. Please find information on how to plant and grow bearded iris here, and beardless iris here.
If it is an established plant that does not perform well anymore, I would refer you to this previously published post on our website, which discusses the issue in detail.
The very mild autumn weather at present has most likely triggered the untimely buds on your iris. It would be unusual to have buds come up in November even if you planted one of the cultivars that rebloom in autumn. Once we’ve had several frosts, I recommend you cut back the bud stalk and remove/cut back all the yellowing leaves to about 3-4 inches above ground. Then, care for you plants as outlined in the links provided above.
If you are interested in knowing more about reblooming iris, see this article by the Brooklin Botanic Garden in New York about Irises for Summer and Fall.
I hope this information will help you grow iris that bloom reliably for you year after year.