Urbanization has resulted in the reduction of wilderness spaces, making horticultural plants the predominant constituents of urban greenspace. This extensive, resource-intensive, and uniform artificial plant landscape hinders the fulfillment of ecosystem functions. Urban spontaneous plants have strong vitality. They are important components of urban wilderness, offering greater economic benefits. In order to explore the low-maintenance community model that sustains high biodiversity, this study took the Chengdu ring road greenway as an example. The dispersal characteristics of spontaneous plant communities and their coexistence patterns with the cultivated plants were investigated and analyzed by employing the uniform sampling method and typical sample method in April and May 2024. The results showed that: 1) A total of 316 plant species were recorded, with 74.68% being spontaneous plants (236 species, including 60 species were escaped from cultivated plants), predominantly indigenous; while cultivated plants accounted for 25.32% (80 species), predominantly non-indigenous. 2) The community area expanded significantly with the increase of species abundance (P<0.001), and the area spread most significantly with the increase of the abundance of annual and biennial plants (P<0.001). Overall, no difference was found among the area of communities in different habitats, but the number of species supported by distinct habitats was significantly different (P<0.05). 3) Niche width of the dominant species of spontaneous plants was generally larger than that of cultivated plants, and most of the spontaneous plants were positively associated. Their association with cultivated plants was moderate, and the community evenness indices of different cultivated plants were significantly different (P<0.001). This study provides a reference for the landscape construction of urban wild and low-maintenance spontaneous plant communities. It explores the possibility of co-construction of spontaneous and cultivated plants from the perspective of diversity maintenance and ornamentality, which provides suggestions for the landscape optimization of spontaneous communities.