One of the gems in the city. It would make my top 10 places to visit in Toronto.
Everyday they have a beautiful and great garden centre that is open. We buy our heirloom tomatoes there every spring/summer. They also have a good variety of succulents and pots. At Xmas they have a huge variety of Xmas trees but I've never bought one there. They aren't cheap and I haven't graduated to a real tree yet. Probably next year.
On the weekend they have a very large farmers market. The Saturday one is bigger and the different days have different vendors. If you are there on a Saturday I recommend the breakfast crepe from the food court. It's a staple for us on any visit to the farmers market. Another staple is starting the visit at Cafe Belong inside for coffee and either one of there delicious biscuits or one of the other baked goods. You won't want to miss these.
If you wonder around or attend some of the ticketed events they hold (cask days, food truck awards, etc) you'll eventually find some old brick ovens. In that same area is where they've had the winter village as well. They also make a little skating loop right beside it. Though one of the best parts about brickworks is the back where the old quarry was that is converted into a park with ponds filled with turtles and fish and pathways you can stroll around on.
The only downfall to this place is you have to pay to park. And if you come for the farmers market around 10am forget about finding a spot. Come earlier or later. Though if you are coming from the east side you can easily bike there now. Though watch out for the scary hill on pottery rd :)