When Garland is unleashed in battle, a targeted non-downed Adept on the player's side is cured by an amount equal to 60% of their maximum HP.
In Dark Dawn, Garland's unleash animation visually resembles the user summoning the 3D model of Garland above the user, and Garland disappears in an orange flash after a moment. Then, the user is surrounded by a swirling orange effect while standing on a fuzzy orange circular field, and by the time it has disappeared, the target is cured. This sequence seems strange because the orange energy that surrounds the user always surrounds the user, whether the user is targeting itself or one of its allies.
Golden Sun: Dark Dawn: Garland reposes in the "second floor" area above Kolima Village, within the maze of branches. The proper entrance to take into this maze is by entering the item shop, going up to its second floor where the mayor woman is, and taking the south exit. You are able to hop along the perimeter of this screen counterclockwise until you end up to the left of the northeast tree. Do not slide down the small slide to the left of this tree - left of the slide is another hoppable path south that leads between the lower two trees, and Garland can be acquired without a fight at the end. While you are here, you can grab the chest at the upper left of the area for Safety Boots, before taking the slide to the exit in the northeast tree.
Because this Djinni is located in a town in the Morgal region which no longer becomes accessible at a later point in the game, Garland can be permanently missed if one enters the final gate in the Belinsk Ruins dungeon. (Late in the game, it is possible to return to Morgal through the Endless Wall glitch. However, this runs the risk of getting trapped in Morgal with no way of returning other than to reset.)
General: While there are very few healing effects in any of the games that restore HP based on a percentage, Garland is generally the least useful because other Djinn that heal by a percentage either heal by a larger percentage or offer some separate advantage to make up for not healing as much, like group healing or acting with increased priority. Unless you are planning to set up for a Venus-element summon by unleashing Garland to heal an Adept's HP, the Cure Psynergy series is overall better despite the PP cost, at least until late in the game - when Garland would probably heal more of an Adept's huge HP meter than Potent Cure. In the GBA games, the Mercury Djinni Fizz is this Djinni's identical equivalent.
Golden Sun: Dark Dawn: While this may appear practical as a battle option, Garland isn't very useful because of the abundance of easy-to-use and direct healing items and Psynergy available. The Djinni that most makes Garland seem inferior in comparison is Coral, found at roughly the same time in Port Rago, which has the impressive effect of healing the entire party by 50%, which is almost as high as the 60% that Garland only heals to a single ally. And later on in the game, the Mercury Djinni Spring will obsolete it by offering a 70% heal. Nonetheless, that it is the one single-target HP-restoring Djinni of the Venus element in this game gives it value, because it can be used to both heal an Adept and set up for a venus-aligned summon (though the same can be said of the one multi-target HP-restoring Djinni of the Venus element in this game, Flower; depending on the situation, Flower's healing effect, which is half as strong but affects four people instead of one, may be preferred).
A garland is a wreath of flowers, branches, and other plant materials worn as an accessory or placed on objects for decoration.