In the final phase of the German Empire, the desire for social renewal culminated in a reform movement that also influenced open space planning. Straightforwardness and formal rigor were intended to ensure better usability. In the Weimar Republic, open space concepts in the spirit of modernism and expressionism also embodied the search for new forms of expression and possible uses. Despite the ambivalence of the trends, however, the reform-influenced design remained dominant.

In 1913, on the occasion of his 25th anniversary on the throne, Kaiser Wilhelm II celebrated himself as Emperor of Peace. It was one of the last self-dramatizations of a monarchy that was to perish in the inferno of the First World War for which it was partly responsible. However, the decades around 1900 were also a time of social renewal in Germany. At the forefront were socio-political considerations and the desire of a strengthened middle class to find more independent opportunities for development and expression for a new, modern attitude to life. The longed-for awakening was reflected above all in a comprehensive reform movement. For garden architecture, this meant turning away from "landscape gardening" in the sense of the Lenné-Meyer school. Working through all conceivable open space planning tasks according to the guidelines of the "Mixed Style", which was either landscape or interspersed with historicist decorative elements, was increasingly perceived as a template. The harshest critics were initially mainly outsiders, artists and architects.

The desire of garden reformers to make open spaces with a wide variety of tasks more functional, simpler, clearer and more user-oriented led to a return to architecturally strict garden styles. Marie Luise Gothein's "History of Garden Art", first published in 1913, is a good example of this, as it aimed to be a comprehensive review of formal historical styles.

The basic work was reprinted unchanged in 1926, which indicates that the reformist approach initially continued unabated even after the brutal caesura of the First World War. Public parks, sports grounds, allotment gardens and the open spaces of cooperative housing estates were predominantly laid out according to the new design maxim. Lively professional exchange and the high level of planning expertise of municipal garden departments may have contributed to the fact that design quality was also ensured through a pronounced typification. The approach was radical and innovative, but at the same time so traditional that it not only dominated during the transition from the German Empire to the Weimar Republic, but was also allowed to remain a "state-supporting" design direction during the Nazi dictatorship after 1933.

Perhaps this fact is responsible for the fact that the permanence of reform-influenced design has often been stubbornly denied in works on architectural and garden history. The Weimar Republic was characterized by alternating cycles between economic depression and a spirit of optimism, between fatalism and the feeling of entering a new age. Naturally, this was also reflected in architecture and garden design. Reformist ideas increasingly coincided with those of the so-called traditionalists and in fact remained predominant.

In addition, however, there was now a phase of much more decisive renewal in architecture, which culminated in the teachings of the Dessau Bauhaus. The clear, cool materiality and formal language of "classical modernism" can also be found again and again in open space concepts of the 1920s. Surprisingly, however, gardens that deliberately sought to express a modern attitude to life often looked very different from what was expected: rather informal and disorganized, but equipped with sunbathing and shower baths, i.e. clearly designed for free, individual use.

Finally, another trend is often forgotten that also stands for and wanted to stand for the awakening of this time: Expressionism, which also influenced garden architecture in the interwar period. Bizarre forms of garden buildings, design elements and selected plants characterized open space concepts that were quite self-confident and innovative. Nevertheless, this design trend was the most hotly debated at the time because its proponents saw it as progressive and modern, while its opponents saw it as merely decorative. A debate that once again reflects the creative and social ambivalence of open space planning trends between the German Empire and the Nazi dictatorship.