Cornfields are known to be sinister in Stephen King works, specifically in 1978's short story Children of the Corn, but the finale of 2020's TV adaptation of villain in 2020's The Stand).
Cornfields show up in this recent miniseries as well, but in a different capacity. The show depicts the fields in connection with "Mother Abigail" Freemantle (Whoopi Goldberg), who's a 108-year-old psychic prophet of sorts during the "Captain Trips" superflu pandemic. She's a force of good to counteract Flagg's malignance, each of the figures garnering their own following during the apocalypse's universal despair and societal upheaval. The first time the show introduces Mother Abigail, she appears to Frannie in a dream — from within a cornfield of all places — urging her to travel to Boulder, Colorado.
In The Stand, the trope of odious fields is inverted and, for this story, they're intertwined with a force of good. In rural Nebraska, Frannie is spooked by Randall Flagg in a darkly hilarious moment where he whispers, "Hey, B****!", causing her to fall in a well and sustain severe, possibly-fatal injuries. It's at this moment that he tries to tempt Frannie, using the possibility of her family's safety as leverage. This is where Mother Abigail (who has died within the course of the show) steps in, her spirit reassuring Frannie that she did the right thing by refusing to cut a deal with Flagg. And then, a reincarnated version of the prophet as a young woman emerges from the surrounding cornfield and assists Stu (who has just returned to the home) in rescuing Frannie.
Mother Abigail even heals her wounds (broken bones and all) so that Frannie joyfully declares, "Nothing hurts, Stu!" Though Children of the Corn has made Stephen King-written cornfields synonymous with evil, The Stand adds a new layer of meaning to them. Rather than an ominous sense of lurking danger, which is present in Children of the Corn and earlier in this very finale, the episode's ending imparts viewers with a sense of good triumphing over evil, of those who stay on a righteous path being rewarded and protected for their faith and good deeds.
As Mother Abigail tells Frannie regarding perseverance in the face of life's seemingly absurd pain, "The wheel keeps turning, the struggle continues, and the call remains the same. Stand." For every Randall Flagg, there's a version of The Stand's Mother Abigail — and cornfields don't always have to be sinister in a Stephen King story.