In Breaking Bad, who do you think poisoned Brock?

Walter White did it so Jesse would turn against Gus. Not sure but I believe Walter slipped it in Brock's food or drink that time when he was over at Jesse's girlfriend's house.

It's not a point of debate: Walt poisoned Brock. The last shot in that episode proved it. Why did he do it? So he could turn Jesse against Gus by making him think Gus did it. How did he do it? He had Hule pat down Jesse and take the risin from him.

As for how the Walt actually got the "Lily of the Valley" to Brock? There are a number of ways. Saul probably helped him, since he had previous contact with Andrea, maybe he gave her some money and gave Brock a candy or something that had the poison in it. I'm not really sure.

EDIT: I completely forgot about that, mick m. He probably did do something when he visited them.

we know it was Walt because he had the Lily of the Valley plant (the thing that poisoned Brock) in his yard, it's the last thing they focused on in that episode, and he threw the plant away as he was cleaning up his tracks in the beginning of the next episode.

We know he orchestrated the whole thing... we just don't know how he got the poison to Brock because it was off screen.

I am guessing he had Sal do it (Brock knew Sal, Sal could get close to him) or one of Sal's thugs.

When he visited he barely got in the door, and had no contact or alone time with Brock, nor was he alone in the room for even a second, there wasn't any way for him to drop poison anywhere.

Since Sal's thugs took the Ricin, it was most likely Sal or his thugs who passed Brock the poison because taking the Ricin shows Sal & thugs were in on that plan.