I went to an open garden the other day, which is a garden at someone's house that is open to the public.
I went to an open garden yesterday. It's a privately owned garden that anyone can visit.
ーI went to an open garden the other day, which is a garden at someone's house that is open to the public.
「先日、一般公開している、ある人の自宅の庭のオープンガーデンに行きました」
open to the public で「一般公開されている」
ーI went to an open garden yesterday. It's a privately owned garden that anyone can visit.
「昨日オープンガーデンに行きました。そこは個人所有の庭で、誰でも訪れることができます」
a privately owned garden で「私有の・個人所有の庭」
ご参考まで！
カナダ 
