What plants do you think is the most useless plant ever? I think the most useless plant is the hypno shroom. It looks beautiful and has a seemingly good effect, but it just doesen't work against the strongest zombies in the game. Which is the gargantuar and zomboni. Also it is only excellent against small amounts of footballs and dancers. It also works against jacks, but you may need some luck.Overall it is too specialized to make work.