Solar parks are currently considered a new source of carbon-free energy. At the same time, they encroach on our landscape and create new conditions for flora and fauna. Vegetation responds to changes in living conditions. The aim of this study was to evaluate the changes in soil conditions induced by solar parks using vegetation bioindicators. A vegetation assessment was carried out in a solar park located in the cadastral territory of the municipality of Unín (Czech Republic). Among the soil conditions observed, this study focused on soil moisture, pH, nitrogen availability, phosphorus availability, and salinity. A total of 77 taxa of vascular plants were identified. Based on the bioindication of vegetation, it can be concluded that there are changes in the conditions between sites under photovoltaic panels (PV) and between rows of PV panels. Under PV panels, species with extreme values of the monitored soil criteria have a higher representation. These species can tolerate salinity, deficiency, or excess nitrogen and phosphorus. Different conditions under PV panels lead to diversity in species composition. This results in significant fragmentation of solar couplet vegetation. However, extreme conditions may create room for invasive plant species to establish themselves. Thus, it is necessary to monitor changes in vegetation, especially under PV panels, in the following years. The characterization of environmental conditions based on vegetation biomonitoring shows the diversity of solar park conditions. Diverse conditions are also important for landscape fragmentation.