Slack Grove was held in June 2021. It was scheduled for June 11 - 13, 2021 but the dates were moved to 18 - 20 June, 2021. It was called the fifth event of the Grove Gathering (although the fourth did not happen due to the pandemic). COVID-19 vaccines were required for those at risk.
The event officially started on Friday, but several people helped set up on Thursday. Moving and clearing the path was already done. The main pavilion was set up. As with the third event, what had been a "mud pit" was full and available for swimming. It was called both Dolphin Lagoon and Mermaid Pond. Everybody still there for bedtime slept under the pavilion.
People who attended included Pagans (especially Wiccans, Discordians, SubGenii, and/or Pastafarians), and others. Most were pretty local, but some came from out of state. It was a naturist event, and included a "troll booth" people had to check through before entering The Grove. Admission was by donation, but those in groups who were recommended to get COVID-19 vaccines by the Center for Disease Control had to present proof of vaccination. Texas law said checking could not be required by a group receiving state funding, but the event had no funding by the state. Maybe because of the restrictions, attendance was smaller than before, with 49 people.
An opening ceremony was followed by singing, instrument playing, and dancing and the Cloved Lemon Kissing Game which was played every day of the event. Essentials such as bottled water were sold at cost. The fireflies were free.
In honor of Juneteenth, there was a free-the-slaves event; the "slaves" were mostly children. It helped to teach them what slavery was and why freedom was so important. It was explained by a teacher. They was also a slavery drama, and people talked about forming a medieval recreation chapter in the area. There was also a spiritual workshop, a dance workshop, and a show by a comical magician. There was also singing and performing by a musical group.
Father's Day and the Summer Solstice were the themes of Sunday. People made tributes to their fathers, There was a ceremony to welcome the Summer Solstice.
There was also an awards ceremony which was mainly tongue-in-cheek. The Best Father award went to the unknown father of Bunny the gray kitten. The best body painting award went to painter Gypsie Skripto and "the body" Urso Negro who had gotten married to Gatina at X-Day Underground in 2018. The Disco-Rdian Dancing Trip won for Weirdest dancing which they claimed they also earned the previous year (when the event wasn't held). Best Gatherington Gazette reporting went to Miley Spears, and Best Name for next year's event is Rainbow Grove made by Dolphin Blue.
The main structures at the event were the pavilion and four portapotties.