Plant growth formula was a potion developed by the Shaman Logray on the forest moon of Endor a short time before the Battle of Endor. The blue-hued potion had the extraordinary ability to make plant-life bloom at an accelerated rate, increasing their size and strength to extraordinary bounds. The original purpose of this formula was likely an attempt to increase the food-bearing plants that were cultivated by the Ewoks of Bright Tree Village. However, the formula was best known for triggering the stranglethorn crisis, when an early incarnation of plant growth formula was accidentally spilled onto a carnivorous stranglethorn by the Ewok Princess Kneesaa a Jari Kintaka.
The effects of the plant growth formula could be counteracted by an antidote made from a mixture of Keet nectar, ganga root, and Trome sap, and Logray kept a vial of the antidote in his hut in case of any abuse of the formula. However, during the event concerning the stranglethorn, Logray's hut was cut off by the monstrous plant, and Kneesaa and Wicket Wystri Warrick were forced to obtain the ingredients for the antidote in another way.