"Flower Child" is the nineteenth episode of Season Seven of ABC's Once Upon a Time. It was written by Edward Kitsis & Adam Horowitz, and directed by Tessa Blake. It is the one hundred and fifty-second episode of the series overall, and premiered on April 27, 2018.
Tilly and Rogers find themselves in danger after an encounter with Eloise, forcing Tilly to make a life-altering decision when Rogers' life is threatened. Meanwhile, Henry and Jacinda's relationship takes a step forward, but despite Lucy's efforts, their union doesn't provide the answers she's seeking. In a flashback, young Gothel seeks revenge after her home is destroyed.
- The title card features a carriage.
- The title of this episode was revealed by Adam Horowitz via his Twitter account on February 9, 2018.
- The CGI model used for Lord Adriel's ball room is recycled from the model used for the Wilmore Estate in 19th Century France in the Season Six episode "A Bitter Draught".
- The background music that plays when Henry and Jacinda are about to kiss has been used for the first time since Ingrid's death scene in "Shattered Sight".
- The Seattle events take place after "The Guardian" and before "Is This Henry Mills?". (For more details, see the Land Without Magic timeline)
- The Land Without Magic flashbacks take place thousands of years ago, before "Second Star to the Right".
- Eloise was first described in "Secret Garden" as being in a cult and being its leader.
- Henry first showed Jacinda the results that prove he is Lucy's father in "The Guardian", and he was shown these results by Nick in "Chosen".
- Lucy insisted to Henry in "Hyperion Heights" that everything in his book really happened.
- Jacinda wonders how she could magically forget that Henry is Lucy's father, an event that began to take place at the end of "The Eighth Witch" when the Dark Curse was cast.
- Henry recalls the first time he met Jacinda in "Hyperion Heights".
- Cinderella was first seen in her blue dress in "Hyperion Heights".
- Lucy gave Henry a piece of the glass slipper in "The Garden of Forking Paths".
- Sabine mentioned in "Breadcrumbs" that she hired Drew to work for her food truck.
- Drew is being interrogated at the police station after being arrested by Rogers in "The Guardian". In the same episode, he told him about Mr. Samdi's role in Nick's death and also steered him into taking a closer look at the unusual manner in how Nick died.
- Drew and Rogers discuss Nick's murder, which happened in "Chosen". Also mentioned by Drew is Nick's hunting of witches, which began in "Secret Garden".
- Eloise admits that she abandoned Alice when the latter was a child, referring to events in "Eloise Gardener".
- Lucy broke into Samdi's home in "The Girl in the Tower".
- Henry's heart was poisoned in "The Eighth Witch".
- Weaver stole Roni's magic in "The Guardian". Additionally, Samdi gave Roni that magic in "Sisterhood".
- Eloise met Margot in a flashback during "Secret Garden".
- Tilly was on the run from the police in "The Girl in the Tower".
- Henry talks about how he saw a photograph of himself with Roni where he was eight years old, an event that took place in "Greenbacks" and "Wake Up Call".
- The origin of the swan keychain was revealed in "Tallahassee".
- The origin of the chipped cup was explored in "Skin Deep".
- Lucy mentions the time Jacinda tried to escape to Bainbridge Island with her, an event that happened in "Hyperion Heights".
- Tilly moved into Rogers' home at the end of "The Girl in the Tower".
- The plant which Gothel sets loose on her enemies is the same plant that Drizella discovered in the ruins of Gothel's old tower in "Wake Up Call".
- Jacinda finds a frog plushie in the box, a reference to Tiana and Naveen, who were transformed into frogs in The Princess and the Frog.
- The film Ratatouille is listed on Henry's board, under Remy's name. Remy happens to be the name of the rat protagonist from the film.
- Henry says he saw a photograph of himself with Roni where he was eight years old, a reference to the second Lost number.
Fairytales and Folklore
- This episode is a rendition of the Rapunzel fairytale, with the origins of Dame Gothel.
- Eloise says that Tilly "was born from both sides of the looking glass", a reference to the novel Through the Looking-Glass.
- Henry references Cabo, a popular resort city in the Mexican state of Baja California Sur.
- Eloise mentions an extinct tree in India called the Arunchal Hopea.
- Isla pours a bucket of mud onto Gothel, who takes her revenge by going to the ball while still covered in mud and using her magic powers to lock the doors and kill all the guests. This is a reference to the famous scene from the supernatural horror film Carrie and the book of the same name, where the bullies dump a bucket of pigs' blood onto the titular character, who then locks everyone in and slaughters all the guests at the school prom with her telekinetic powers.
- The box where Henry keeps the piece of Cinderella's glass slipper is the same prop that was used for his mother Emma's box of keepsakes in the Season One episode "The Price of Gold", the Season Four episode "Breaking Glass" and the Season Six episodes "Tougher Than the Rest"  and "The Song in Your Heart".
- Tilly plays with a white origami rabbit in Rogers' car, a reference to the White Rabbit from Alice's Adventures in Wonderland. There are also toadstool decorations on Rogers' dashboard, a reference to the magic mushrooms from the story.
- On one of Henry's bulletin boards, Roni is also listed under the name "Rani". "Rani" is Sanskrit for "queen".
- The photograph of Black Beard on one of Henry's boards is taken from a behind the scenes photograph of actor Charles Mesure from "Fall".
- The name Gina Mackay appears on one of Henry's bulletin boards. This is a real-life person who works as a graphic designer on the show.
- The scenes at the house where Isla, Seraphina, and their house sisters are trying on dresses was filmed at Foxglove Farm, a 120-acre organic farm on Salt Spring Island in British Columbia.
- The same building doubles as the exterior of Edwin's home in Once Upon a Time in Wonderland,, the Tremaine Estate in "The Price of Gold" and "The Other Shoe", as well as the Tremaine Estate in "One Little Tear".
- The same farm doubles as the Storybrooke Pumpkin Farm for the episode "The Other Shoe". The scenes at the pumpkin farm were shot at the back of the building that doubles as Lady Tremaine's house.
- The house which doubles as the family's home was also used in the filming of the Timeless episode "Party at Castle Varlar", an episode which features Once Upon a Time starring cast member Sean Maguire and guest star Chad Rook, and the Beyond episode "Tempus Fugit", a show which stars Once Upon a Time actors Jonathan Whitesell and Jeff Pierre. The house was also featured in the Supernatural episode "Everybody Hates Hitler", the Arrow episode "Bratva" and The Magicians episode "Have You Brought Me Little Cakes". It also doubles as the Salvatore Boarding House in the Pilot episode of The Vampire Diaries and is heavily featured as Thistlehouse during Season Two of Riverdale.
- The scenes in the Tree Nymphs' Grove were filmed on a blue-screen set. While the most of the interior was real, the background was added digitally in post-production.
- The scenes in Lord Adriel's Ball Room were filmed on a green-screen set at The Bridge Studios.
- The Paramount Gentlemen's Club in New Westminster doubles as The Hyperion Theater for exterior scenes.
- The scenes in Mr. Samdi's office were filmed on a television set at The Bridge Studios.