The crisis then abruptly ends, and at the conclusion of the film, an expert on television confirms the "killer plants" theory, and then we get a hint that the whole thing is about to start again.
That plot is fertile ground for all sorts of unintentional hilarity, as our characters have to frantically flee from a grove of gently rustling trees. Lest you think I'm joking, here's the infamous "running from the wind" sequence, wherein everyone splits into smaller groups to evade ... Jesus ... the wind, so that the plants won't detect them.
That makes no sense as a defense mechanism, even within the framework of the story. The wind at this point is either laden with toxins or it isn't. Splitting into small groups after it is already blowing toward you isn't going to help.
To make it stupider, in another scene, a few travelling survivors chance upon a bunch of people who have killed themselves. They immediately shut the windows of the car, only to discover a small opening on the roof, which is enough for everyone to become "infected" and also commit suicide. How can this tiny slit possibly be large enough for the plants to detect the handful of people in a car, if it's a foolproof plan to stay in the same-sized group when moving around outside later?