We visited here in the winter with our handy Museum pass. There are 10 greenhouses to tour (although one was closed getting ready for a butterfly exhibit). Overall I thought the collection was very nice, especially the bonzai area.
But what really made this place shine is the lovely accomodating cashier. My husband and I had purchased the Montreal Museum pass the day before for $50 a piece. They get you into pretty much anything in the city. Well, my husband, managed to lose his. He ended up retracing our steps (in the bitter cold) only to end up empty-handed. So I used my pass and had my cash out for him. We mentioned our misfortune and the guy worked his magic and let my husband in for free saving us roughly $13. After thanking him profusely we walked through at a leisurely pace happy to see some green in the middle of winter.