…this puzzle is rubbish.
Putting themes into cryptic crosswords should be a mutual pleasure for setter and solver. For the solver it’s something a bit different and for the setter a chance to stretch their technique beyond the typical daily model. It’s like saying to the solver “If you’re prepared to put the time and hard work into solving my clues I’m prepared to return the favour by challenging myself”. Often, sadly, it doesn’t work that way.
The problem is the theme itself – at what point does general knowledge become something specialist? What’s the difference between several answers being the names of trees and several being famous golfers? To my mind there is none at all; further, I’d say that the term ‘general knowledge’ is pretty ineffectual, certainly when it comes to a themed puzzle. As far as I’m concerned only a non-themed puzzle deserves to be called that.
For those who take part in pub quizzes, a general knowledge round is one in which all the questions are on different subjects, and a standard cryptic puzzle is the same. The grid may have a smattering of geographical locations, figures from history and literature, political references, sporting references etc etc. Those are general knowledge questions, but so is “What word for X uses the components Y and Z?” and the answer you want may be as apparently non-GK as HANDCART but it’s still asking you to recall knowledge of something.
A themed puzzle is going to revolve around a particular subject so it is, by definition, specialist. Fish? Well, as a setter I’m familiar with the ones we setters find useful in clue-writing, but if you showed me fifty photographs of various fish I might, at a push, name three or four. To me it’s a specialist subject – just like trees. Yet we seem to face the strongest objections when we focus our setting efforts on sport, TV programmes, the works of a particular composer or author and countless other subjects.
Some may argue that a theme becomes specialist when you can’t look up the answers in a standard dictionary, but that isn’t really relevant. For all standard cryptic series there is a fundamental policy of making each puzzle solvable without a dictionary – perhaps that will involve taking the occasional punt at an answer and seeing if the wordplay matches up then checking the answer later, but so many people now go online the idea of checking with a dictionary has become almost anachronistic.
When the 225 puzzle you’re solving uses a theme, just enjoy it for what it is. It’s a setter putting in extra graft for your entertainment. You may not like the subject, but others will and, at the very worst, in solving it you’ll have more nuggets of info/trivia to store and remember for next time they crop up.