Our article provides data of 186 spreading cultivated taxa in Hungary. Among these, the spreading of 40 species in botanical gardens was not known until now. During our work, we examined the arboretums of Ti­szakürt, Szarvas and Erdőtelek, the agrobotanical garden of Tápiószele (located in the National Centre for Biodiversity and Gene Conservation), the botanical garden of the Eszterházy Károly Catholic Uni­versity in Eger and the De la Motte Castle Park in Noszvaj. We collected further data on the lately iden­tified Cardamine occulta and the spreading Veronica peregrina taxa, which spread mainly through plants sold in pots. Besides the already known two Juglans species, we found four new potentially spreading ones from the family of Juglandaceae (Carya cordiformis, C. ovata, Juglans cinerea and J. microcarpa). We also found seedlings and saplings in the case of all the investigated Abies species. We found the seventh Hungarian occurrence of Ludwigia grandiflora in the artificial lake of the Arboretum of Szarvas. The quantity of new occurrences reported in this paper highlights the need for further research in living collections in Hungarian botanical gardens.