Is it the park that closes at 4 or just the green house? Can we go there at anytime?

Yes Greenhouse area closes at 4.when I visited they were about to close- park can be visited after that as well

I think it's just the greenhouse that closes at 4. Parking is limited so consider the new Blue Line.

Careful where you park. Check the website for info

Pretty sure it is just the greenhouse and not the park that closes at 4pm