Breaking Bad: Explain the whole ricin thing to me please (spoilers)

[bosox32]

I don’t remember Jesse ever seeing the flowers at Walt’s house.

It was more of him putting the pieces together of Walt manipulating him during the Gus Wars and hurting Brock to kill Gus.

 

[DoomPatrol]

Jesse only put together the pick pocket. He also knew that it was at that same time as Brock being poisoned. I think at that point he assumed Walt had figured out someway to poison Brock but didn't know how.

Saul confirmed his suspicions when confronted over the pickpocketing of his ricin cigarette. Saul literally says something along the lines of "but I didn't know what he was going to do with it. He never said he was going to hurt the boy".