Does a beer in a beer garden count as a new pub tick?

[Pangolin]

Whether you "tick" a pub or not is entirely up to you. It's not a competition and there are no rules.

Writing a review and ticking the pub are not necessarily the same thing.

Quite, on both counts. I record pubs that I have visited and "sampled the hospitality" of, for my own interest (although I can't think of any such that I have not been inside, even if mainly drinking outside). I will always try to review a pub so far as possible, especially if there is no previous /recent review, with appropriate comments if parts not visited, beers not sampled or whatever.