I think it is supposed to come up because that is a part of the storyline. To avoid having to battle the Jinn at the bushes you could trigger a Jealous Leprechaun from the dead trees or an Angry Leprechaun from ponds or wells first. If there is already a monster in your kingdom, the Jinn will not be triggered in the bushes and you can safely collect other useful items around your kingdom as well. Good luck.