Before it became an amusement park open to the public, it was known as Tree Haven, and was a commercial plant nursery, as well as a recreational facility for employees of Nob Hill Foods.

The most well known garden features 24 Circus Trees that were grown and shaped with multiple trunks, basket-weave patterns, and hearts by the late Axel Erlandson.

[4] Cedar Fair (now Six Flags) acquired Paramount Parks from CBS Corporation in June 2006 and continued the management contract to operate Gilroy Gardens.

It reopened in May 2021, and since then it has been restricted to California residents and adhering to strict measures like social distancing and wearing masks.

[9] The park also uses seasonal mascots for its Great Big Boo and North Pole Nights events.