As a reddit user here is my experience. Reddit's search tool is terrible if you want to find a thread about a specific topic. It only searches for exact keyword matches and only in the title, not in the thread body. Add to this the fact that reddit users have a habit of link baiting their submission titles such that the titles rarely have any useful information and the search function is practically useless.

If I want to check reddit's opinion on something I have to resort to doing a google search like "site:reddit.com lopping tree branches".