Jayapataka Swami: Normally one wears two to five Tulasi malas. Sometimes they prescribe one mala to be for new devotees. But where it is said in the sastra, I have never seen. More than five is considered as too much! And normally one wears Tulasi mala, kanti mala, around the neck from two to five. If one wears Tulasi necklace around the neck, it may be single. Just for practical reasons.