Bush Outside Elevator

I'm trying to get the bush outside the elevator to burn and it won't accept the flammable liquid. I have the cup of flammable liquid and the burning match. When I try to pour the liquid on the bush, it says, "Delicious shrubbery nectar? Nah." And when I try to use the match afterwards, it says something along the lines of "it's too dry" (which makes no logical sense but we'll overlook that).

Am I missing some other step that's needed before I can burn the bush? I've taped the wires together and opened the keyhole on the gate lock. According to the walk-through, I should do the bush next. Is this a glitch or did I miss something?

Thanks in advance!