IIRC in Seattle it effectively depends on whether anyone cares enough to report you. If your neighbors don’t mind you gardening naked in your front yard then you’re fine. If they gripe about it then you have to put clothes on.
That’s not the case. You do not have to put on clothes just because your neighbors don’t like it. Gardening nude is fully legal even if someone complains.
Nudity itself is not obscene, only obscene actions can make it obscene.