The defeat in World War I and the revolutionary events of 1918 brought an end to the monarchy and led to the formation of the Weimar Republic in 1919. In 1920, on the basis of the law of April 27, the new municipality of Greater Berlin was established, with 3.8 million inhabitants.
Director of city public gardens Albert Brodersen now served as head of the Parks and Cemetery Systems Division, until leaving office as city public gardens director in 1925. Borough departments of public gardens were set up in the twenty boroughs. The director of city public gardens was responsible for the general guidelines for the care and maintenance of all public facilities and planting, including the cemeteries, as well as for the supervision and management of all municipal plant-raising facilities, the procurements of materials and the regulation of basic labor issues. He also had to check the designs submitted by the borough departments of public gardens for new facilities, especially their cost estimates and budgets. With the exception of the Großer Tiergarten, which remained under its own Tiergarten Inspection Agency until 1954, responsibility for the care and maintenance of all parks and green spaces was transferred to the boroughs.
In 1921, there were 1,339 ha of parks, green spaces and decorative squares (1.5 percent of the Berlin city area).
In order to find jobs for the large number of unemployed people after the defeat in World War I and the subsequent disbanding of the army, the influx of many refugees and especially the worldwide economic crisis, Berlin’s Mayor Gustav Böss (1871-1946) in 1921 established an emergency program at the level of 45 million RM, jointly funded by the national, state and municipal governments. The program included the construction of forty-three major projects for playgrounds, sports fields and parks. By 1924, the twelve largest projects had been completed.
From 1920-1923, the 160 ha Volkspark Jungfernheide (Maiden Heath Public Park) was created, as designed by Charlottenburg borough public gardens director Erwin Barth.
Treptow borough public gardens director Ernst A. Harrich (1886-1941) created the 175 ha Volks- und Waldpark Wuhlheide (Wuhlheide Public Forest Park; in German), the largest public park in Berlin. In addition, the 13 ha Volkspark Mariendorf (1923-‘24) and the 30 ha Volkspark Tempelhofer Feld (Tempelhof Field Public Park), (1921-‘27) – the latter only existed for a few years – were also created.
The public parks were distinguished by a large variety of use opportunities. All strata of the population were to be provided with the space and the opportunity to spend time in the public parks at any season of the year. They were to be able to enjoy games and sports there, but also to find space for tranquil resting. Instead of “decorative value,” the public parks were to provide “use value.”
An additional 35 million RM were appropriated to continue the emergency employment projects between 1924 and 1927. Up to 8,000 unemployed persons were employed at times.
In addition to the public parks, many smaller parks were also built during this period: the 10 ha Lietzenseepark (Lietzen Lake Park) (1912-‘20), by E. Barth; the 2 ha Brixplatz (1919-‘21) by E. Barth; the 7.5 ha green spaces with bathing facilities at Plötzensee (Plötzen Lake) (1923), by R. Germer; the 6 ha Südpark South Park in Spandau (1923), by R. Woy; the 9 ha Fischtalpark (1925-‘29), by M. Dietrich; and the 5 ha Schulenburgpark in Neukölln (1924), by O. Wagler.
Since 1920, Berlin’s public green spaces have been expanded by 1,300 ha.