The episode starts at South Park Elementary where Mr. Mackey is speaking to Randy and Sharon about Shelly's behavior. He tells them she has been vaping, and has distracted the recess monitor from it by sending a picture of her butthole, which is really a picture of a dog's butthole.
Randy berates her in the car, before telling Sharon he's had enough of South Park with all the recent events. He tells her he dreams to live on a farm, and he wants to do it now. A montage is then played, withOn a Colorado Farmplaying, as the family put their house up for sale and move to Tegridy Farms where he grows weed, like other farmers.
Back at school, Stan tells the Boys he's annoyed he has to spend an hour getting to school just because Shelly was vaping. Kyle questions why she was vaping, leading Cartman to tell him Ike is vaping too. The boys go to tell Ike off and find all the kindergarteners are doing it as they "need a break". They then go to find the person selling the vapes, who turns out to be Butters. Butters tries to sell some to the boys, so Cartman punches him "for Kyle".
On Tegridy Farms, Randy has made friends with the locals, and awaits the agricultural inspector's visit. The inspector, Towelie, turns up to test the product. He starts getting high from the product and says it is "good shit", and Randy celebrates.
Cartman is sitting on the toilet at school when Butters bursts in, angry. It is revealed the two are working together, and he hit Butters because he blew their cover, and people couldn't find our because they are already falling behind. He lets Butters out as Kyle watches in the background. Before Kyle can say anything, he notes that "vaping is better than smoking", leaving Kyle dumbfounded.
Randy gives out supper on the farm when a man comes to buy the product. Randy is interested until he discovers the product is needed for vaping, which Randy regards as "pussy sticks". The man leaves, angrily, saying he will be back.
At school, Kyle tries to meet with the principal about the vaping, but Cartman and Butters are already there. Cartman tries to persuade him not to tell the principal, explaining they want to get out of the business, and will do once they pay off their debts. Kyle makes him promise not to push it on to kindergarteners.
Randy is working on the farm when he notices a nearby farmer selling his crops to the vaping market. He berates the farmer, saying he has no "tegridy", before angrily walking inside, where he finds Towelie in the corner, having gotten really high.
In the school cafeteria, Cartman and Butters try to advertise vapes to the boys through acting. They then get a mascot, known as the Vaping Man (a parody of Kool Aid Man). Kyle stops him and asks to speak in private. Away from the others, he yells at Cartman, saying this is still pushing it onto little kids. He then asks how much debt needs to be paid.
Back on the farm, Randy and Stan are churning milk together. Stan expresses his hatred of the farm and of Randy, which Randy believes means the two are bonding. He then gives Stan a hemp hat, which plays Two Princes when worn.
Outside Big Vape Colorado, Kyle tries to make a deal with the person Cartman and Butters owe money to by giving him his birthday money, making the dealer feel ashamed. Cartman and Butters drag a "dead hooker" up next to the dealer during this exchange, then frames the dealer, and the three boys run off.
Over dinner on the farm, Randy asks how everyone's day has been. Sharon casually mentions Stan was caught with a vape pen. Randy then sends Stan to his room and berates Sharon for underreacting. He then tells off Stan, who says he took it from a kindergartener. Randy, angry, goes off to fight the vape company.
Kyle goes to the Mackey Residence to tell Mr. Mackey about the vapers, only to find Cartman and Butters there. Cartman takes him to the side to tell him that The 6th Graders are angry that they took out the dealer. He informs Kyle of his plan to rob the vape shop, as they still owe people money, including the vape man, who bursts in demanding his money.
Randy gets ready to fight the vape company, drinking hemp milk and wearing the hemp hat, before running out to fight.
He turns up at Big Vape on his tractor and fights the vapers inside. At the back of the shop, Kyle, Cartman, and Butters are syphoning the e-liquid. They are spotted by the man who tried to buy Randy's crops earlier. Randy then comes up behind him, and Kyle confesses to him everything. The man then starts fighting Randy and almost wins, until Towelie shows up behind Randy to fight him. After the fight, Randy opens all the valves for the e-liquids and sets it alight before running out. The building then blows up, with Butters questioning if they are out of the vaping business now.
Stan, Randy, and Towelie are on a tractor farming, with Stan still annoyed. Randy tells him that the fight is just beginning. The episode ends with an advertisement for Tegridy Weed.
AV Club gave "Tegridy Farms" a "A" rating saying: "After last week’s shaky outing, I was beginning to have mixed feelings about season 22, but “Tegridy Farms” featured Trey and Matt back on their game. The shots at both vape culture and weed culture were hilarious, and it was good to see a plot that featured a great Kyle/Cartman/Butters adventure, as well as the welcome return of Randy’s love affair with weed."
IGN gave "Tegridy Farms" a "9.2/Editors Choice" rating saying: ""Tegridy Farms" is easily one of the best South Park episodes in several years, in large part because it captures so much of what made the show stand out in its earlier seasons. It features a healthy sprinkling of topical humor but a ridiculous storyline that can hold up over time. It also banks heavily on the appeal of Randy without completely ignoring the younger characters. And this episode lays the groundwork for what could be a fun recurring motif this season if the writers choose to exploit it."