I'm trying to figure out whether to use a comma in a sentence of this construction:
The tomato is red placing it on the warm end of the colour spectrum.
The tomato is red, placing it on the warm end of the colour spectrum.
The sentence above is nonsense (I'm not a native speaker), it's just an example. I tried to simplify as much as I could to avoid jargon which is irrelevant to the question anyway.
I've tried looking it up, but either the question is too specific for the websites I've been looking at, or I'm not using the right search terms. Does anybody know which is correct?