Originally Posted by jetscollector10
I thought that Walt didn't poison Brock with Ricin. He used a homegrown plant instead... So why did he need the ricin from that??
To convince Jesse it was Gus and to get him on his side to put it simply.
Anyway, here's Huell taking the weed in the latest episode for those who missed it:
Anyway, here's reddit's breakdown of ricin events: