The flowers were watered when you came

Hello!
The sentence: “The flowers were watered when you came.” is correct? or maybe the better option would be: “The flowers were being watered when you came.”?
Thank you for your time and support!

(1) “The flowers were watered when you came” is the passive of “We watered the flowers when you came.” In other words, you came at 3 p.m. And we started to water the flowers at 3 p.m.

(2) “The flowers were being watered whern you came” is the passive of “We were watering the flowers when you came.” In other words, we started to water at 2:45 p.m. When you arrived at 3 p.m., you saw us already watering the flowers.

When I read “The flowers were watered when you came”, my first thought was that watered was being used as an adjective, so the sentence meant “The flowers were already watered when you came”. It can of course also mean James M’s explanation 1, but be aware of the possible confusion.

Thank you a lot for explanations!

And thank YOU for your kind note.