Which one is correct:
1. A house surrounded by green.
2. A house surrounded by greenery.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.
Depending on the context, both might be correct.
"A house surrounded by green" might be correct in the context of a house set among green fields or forests [perhaps at some distance from the house], whereas "a house surrounded by greenery" is a house surrounded by bushes or trees, or anything else with green leaves. "Greenery" implies something cultivated for decoration.
I'm not a teacher of English, but I have spoken it for (almost) all of my life....
"My parents live in a small cottage in the countryside. It's surrounded by green and it's got a well-kept garden"
So both 'green' and 'greenery' are possible here but with a difference in meaning?
I can't imagine ever saying a house was surrounded by green.
Maybe if I was talking about a painting.