Tree of heaven is one of the most widespread non-native tree species in Slovenia. Under certain conditions, the species can be very invasive. We concluded that the presence of seed trees of tree of heaven favorably affects the dominance of the species. The light conditions positively affect tree of heaven regeneration density, since the species is very light demanding. If there are no seed trees of tree of heaven in the vicinity and if the species is growing under the shade, the native tree species may successfully compete with tree of heaven. Since the use of chemical pest control is illegal in Slovenian forests, we tested three mechanical removal methods. Breaking of primary growth showed non-favorable results. The total removal (seedlings were pulled out) of tree of heaven showed the best results, we advise for it to be used in combination with the shading of tree of heaven by native species if possible. Breaking of secondary growth showed mixed results. In this case tree of heaven survived in quite high rates but its growth was significantly reduced.