Where to find Xurkitree in Sun, Moon, Ultra Sun & Ultra Moon

Static Encounter: Lush Jungle (Only in Sun & Moon), Memorial Hill (Only in Sun & Moon), Ultra Space (Only in Ultra Sun & Ultra Moon)
Walk: Lush Jungle (100%, Only in Sun & Moon), Memorial Hill (100%, Only in Sun & Moon)

Xurkitree also appears in

How to get Xurkitree in Sun, Moon, Ultra Sun & Ultra Moon

Its base catch rate is 30 out of 255 (higher is easier); the catch rate calculator works out your odds with each ball. For the look, the best colour match is Ultra Ball or Beast Ball.

Xurkitree in every game · Pokémon Sun, Moon, Ultra Sun & Ultra Moon interactive map (Alola)