He was not a mere historical researcher of gardens but also produced gardens himself such as Tennoji-koen (Tennoji Park), outer park of the Ise Kotai-jingu Shrine and the Toyouke-daijingu Shrine and he restored scenery in Ritsurin-koen park and even produced a Nihon teien exhibited in The Japan-British Exhibition held in London, and Kyuka-koen Park for centennial festival of Sadanobu MATSUDAIRA at his own birth place, Kuwana City, Mie Prefecture built in 1928.
小沢は単なる庭園史の研究家でなく自らも日本庭園を作庭し、天王寺公園や伊勢皇大神宮・豊受大神宮の外苑、栗林公園の修景のほか、ロンドンで開催された日英博覧会に出展された日本庭園、また自身の故郷三重県桑名市では1928年に松平定信百年祭にともない造られた九華公園などの作品がある。