During 2017, the Westerdijk Fungal Biodiversity Institute (WI) and the Utrecht University Museum launched a Citizen Science project. Dutch school children collected soil samples from gardens at different localities in the Netherlands, and submitted them to the WI where they were analysed in order to find new fungal species. Around 3000 fungal isolates, including filamentous fungi and yeasts, were cultured, preserved and submitted for DNA sequencing. Through analysis of the ITS and LSU sequences from the obtained isolates, several plectosphaerellaceous fungi were identified for further study. Based on morphological characters and the combined analysis of the ITS and TEF1-α sequences, some isolates were found to represent new species in the genera Phialoparvum, i.e. Ph. maaspleinense and Ph. rietveltiae, and Plectosphaerella, i.e. Pl. hanneae and Pl. verschoorii, which are described and illustrated here.