First, string trio in cafe damaged plants (9)
I believe the answer is:
factories
'first string trio in cafe damaged plants' is the definition.
I can't tell whether this defines the answer.
'trio in cafe damaged plants' is the wordplay.
I cannot really understand how this works, but
an anagram of 'trio' is 'tori' which is within the answer.
an anagram of 'cafe' is 'face' which is located in the left over letters.
A single letter 's' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for factories that I've seen before include "Manafacturing plants" , "Manufacturing plants" .)