My Rosemary has been growing but turning black at the tips (see below). I've tried pruning these black tips off once and it seems to stimulate new growth. But, the black tips show up again after a few days. And, it's black for almost every new stem. What can be the cause of this?

Additionally, I'm thinking of moving it onto the ground since I currently place it on my balcony.

(Black tips of one stem)

(The black tips are at every stem.)