Contemporary cities are mostly seen through the lens of organised greenery, while the potential of unorganised greenery growing on wasteland and post-industrial sites remains underappreciated despite being equally valuable. In such places, nature itself shapes plant communities that are best adapted to difficult environmental conditions, contributing to soil remediation, water retention, and biodiversity. Examples from Silesia, such as the Silesian Park, Żabie Doły, and Uroczysko Zielona show that nature can be an effective partner in the process of revitalising urban spaces. The concept of a ‘novel ecosystem’ created by plant succession in degraded areas points the way towards sustainable urban development in the face of climate change. Therefore, we should learn to trust nature and consider it an ally in urban planning.