Dry mouth is one of the more universally reported antidepressant side effects, and trazodone is no exception, although its anticholinergic burden is milder than older tricyclic antidepressants like amitriptyline.
Sipping water, chewing sugar-free gum, or using saliva-substitute products can help. Persistent dry mouth can also increase dental cavity risk over time, so mentioning it to a dentist is reasonable if it continues for months.