Once you’ve dealt with the zombies, head west down the Lounge. These will reanimate and attack you later, so it’s best to take them out now, one at a time. You’ll be in the Lounge, a room filled with corpses. Now go around the other side of the room, through the door, and straight on. Head right to grab a map and some Gunpowder Large. Now head back into the greenhouse and turn left when the path splits, then left again and down the open hatch. Check the video at the top of this page (7:40) for the solution. Use the Dispersal Cartridge on the console within to mix the Herbicide. Now head into the greenhouse and stick to the left until you get to the Drug Testing Lab. Opening both of these now will save you a bunch of time.
This one removes the security lock on a mixing console: Interact with the solution dispersion console to get the Dispersal Cartridge, then go to the display console and input these symbols: Head through the door at the other end of the corridor and you’ll be in the Greenhouse Control Room. Resident Evil 2 Remake S Rank guide for Leon A - Herbicide Puzzle The best thing to do is just melt them with your flamethrower and pass when they fall to the floor squirming. There are some plant enemies in here and they can kill you in one hit if you don’t have a grenade or knife on you. Go left and enter the door in the corner, into the overgrown corridor. Stock up and save in the Lobby, then head through the door on the east where you'll be greeted by a doctor pinned to a window on the other side.
Use the terminal to extend the bridge, then do the same on the other end to access the East Area. The new security clearance will get you through the other door in here now. Leave the room, deal with the armoured zombie in front - aim for the head - and through the door straight ahead, looping back around to reception. Now grab the Electronic Chip security clearance from the dead arm poking out of a sleeping pod and combine it with your ID Wristband. There’s some Shotgun Shells in here, as well as a Flamethrower Regulator in the lockers. Follow the vent around until you drop down into the kitchen, then exit the kitchen and head to the door on your right. Head straight there through the dark corridor, ignore the zombies inside and get straight up the ladder. Your next stop is through the Cafeteria in the west. Next, go into the Security Room opposite and grab the Shotgun Shells and map. Make sure you have at least one healing item and some ammo on you as well. Once in Nest, go to the safe room at reception and make sure you put away any key items you’re carrying - you won’t need those here.