Can a blueberry bush be overwintered outside in a pot in toronto?
Success in over-wintering plants depends on many factors, including:
- size of pot (Use a container as large/deep as possible, keeping in mind weight if it sits on a balcony);
- winter hardiness of plant (Plants should be two zones hardier – for example, Zone 4 if you live in Zone 6);
- prevailing winds (Cold winter winds can be damaging to any plant)
- insulation over winter (A thick topping of snow or mulch can prevent the freeze-thaw cycle that can kill roots)
Blueberries also have specific requirements, including acidic, well-drained soil. They also have a shallow root system that will need winter protection. This blueberry fact sheet from OMAFRA is designed for the home gardener:
https://www.omafra.gov.on.ca/english/crops/facts/90-046.htm
I don’t usually like to post links to information that isn’t from an educational source, but I know Kerry Michaels as a very knowledgeable writer about container growing. She has this to say about growing blueberries in pots:
https://containergardening.about.com/od/vegetablesandherbs/a/Growing_blueberries.htm
So the answer is a tentative yes – depending on the factors above. Hope this helps. If not, perhaps you can tell us more about your specific situation? For example, will the container be on a balcony?