Today, the city park also features a romantic rose garden with around 4,500 roses. It was laid out in 1925 on the occasion of a rose show according to plans by Nierstein-based landscape architect August Waltenberg. The basic idea was to create two perpendicular axes, which still exist today, with several different areas. The rose garden was significantly expanded and modernized for another rose show in 1935. In 1962, the area was listed as a historic monument after further redesign.

In 2013/14, the structures in the rose garden underwent extensive renovation. In keeping with historical models, vegetation work such as the renewal of rose varieties and the planting of shaped hedges was carried out, and paths, natural stone walls, sculptures, and seating areas were also thoroughly renovated. Furthermore, the Mainblickbrunnen fountain was rebuilt and, with its water feature beneath old trees, contributes to the special atmosphere of this part of the city park.

Rose lovers can admire around 100 climbing and shrub rose varieties across an area of 9,500 square meters. The rose garden in Mainz City Park is the perfect place for a leisurely stroll. During the Mainz Wine Market, the rose garden hosts an artists' market and a small antique book market.

In the immediate vicinity of the rose garden is the aviary, which is also of interest to visitors.