The series centers on two half-brothers who travel through a mysterious forest to find their way home, encountering a variety of strange and fantastical things on their journey.

A three-minute stop motion short film, produced by Aardman Animations, was released on November 3, 2024 to celebrate the 10th anniversary of the series, bringing back several cast and crew members, including McHale, Wood and Lynskey.

[5] The series follows two half-brothers, Wirt and Greg (voiced by Elijah Wood and Collin Dean respectively), who become lost in a strange forest called the Unknown.

To find their way home, the two must travel across the mysterious forest with the occasional help of the wandering, mysterious and elderly Woodsman (Christopher Lloyd) and Beatrice (Melanie Lynskey), an irritable bluebird who travels with the boys to find a woman called Adelaide, who can supposedly undo the curse on Beatrice and her family and show the half-brothers the way home.

Stalking the main cast is the Beast (Samuel Ramey), an ancient creature who leads lost souls astray until they lose their hope and willpower and turn into "Edelwood trees".

Wirt, while attempting to take back a tape of poetry and clarinet music he made for a girl he is infatuated with, followed her to a ghost story party in a graveyard.

To save Greg from being hit by a train, Wirt pulls him off of the tracks, causing both of them to roll down a hill into a pond, knocking them both unconscious.

The series would follow two brothers—Walter and Gregory—who, after signing themselves into a Faustian deal with a devil named Old Scratch, journey across the Land of the In-Between to track down the pages of a book of forgotten stories.

[7] McHale abandoned the original idea centered around chapters of a mystical tome and the series' title became Over the Garden Wall.

McHale initially envisioned eighteen chapters in the series, but the episode count was brought to ten to accommodate budget and time constraints.

Early drafts of episodes from the show's pitch bible included a skinless witch character and a villain who carves dice from the bones of kidnapped children, as well as a running plot throughout four episodes in which Wirt and Gregory are transformed into animals (Gregory being a duck and Wirt being "either a bear or a dog ... Nobody can tell which").

[17] McHale referenced chromolithography, vintage Halloween postcards, magic lantern slides, and photographs of New England foliage to create the show's style.

Greg gives the tape to Sara's friends, who tell Wirt that another boy, Jason Funderberker, intends to ask her out at a party that night.

[38][39][40] Over the Garden Wall (with the short film Tome of the Unknown) was released on DVD in Australia by Madman Entertainment on July 8, 2015,[41] and by Warner Home Video in the United States on September 8, 2015.

[42] The DVD features all ten episodes of the show, commentaries, the original pilot, alternate title cards, and deleted animatics.

Other extras on the DVD include a "Composer's Cut," an option wherein a viewer can watch the show with only the visuals and the background music; and the mini-documentary Behind Over the Garden Wall.

The website's critics consensus reads, "Over the Garden Wall's modern sensibilities mix well with its fairy-tale setting, creating a whimsically witty series for viewers of all ages.

"[46] Preceding its premiere, Patrick Kevin Day of the Los Angeles Times called it "funny, creepy" and, from the premise, "not as simple as it sounds".

[7] In TV Guide and also before the premiere, Megan Walsh-Boyle felt that the show's fictional universe "sounds like a world worth getting lost in".

[12]: 24  Meredith Woerner of io9 called a preview of the show "amazing", "weird, and cute and great", reflecting "all the things we love about this oddball animation renaissance we are currently living in".

[49] Lloyd later wrote that it evoked "a kind of artisanal quality", both in its design and setting, and though the writing felt "a little too intent on its own folksiness", it became more enjoyable throughout.

[50] In The New York Times, Mike Hale also felt the writing was sometimes weak and the stories "perilously thin", but concluded that McHale developed an environment worth visiting.

[51] Brian Moylan of The Guardian wrote that the visuals were "absolutely stunning", and that the stories contained "a certain darkness to it that is both mellow and twee at the same time, with a fair amount of anxiety creeping around the edges".

[52] Brian Lowry of Variety wrote that Garden Wall was "an admirable experiment", but not one to sustain "the five-night commitment", calling it "slightly mismatched" while praising a departure from "the more abrasive characteristic" of the network's primetime content.

[53] Kevin McDonough of the Illinois Daily Journal criticized some of the writing, but summed it up as "an ambitious cartoon" for both younger and older audiences.