這個花園應該不全部是公園。寫的至少不是通俗英語。

A public garden is an institution open to the general public for education, enjoyment, research, conservation, and learning, while a "reserve garden" is not a standard term and may refer to a public garden with protected areas, a specific type of non-public garden like a research or private reserve, or a misunderstanding of the term "botanical garden".