The North American ash-leaved maple is one of the most dangerous invasive species in Russia. However, due to the high seed production and the ability to grow in the environmentally unfriendly territories, it spread widely in Moscow, forming the tangle of tilted and curved trees, which are not much decorative. The rapid reduction of the ash-leaved maple population may exacerbate the adverse environmental situation in the city. The study of the species’ biomorphological features, as well as the consequences of the spontaneous pruning performed by the landscapers, makes it possible to issue recommendations on adjusting the crowns of curved and tilted trees, multi-stem trees, as well as on improving the appearanceof tangles. Thanks to the dormant buds, A. negundo easily tolerates the most radical variants of rejuvenating pruning, allowing to reduce the crown of trees to a height of 3–4 m, to form low-growing trees with a height of 1.5–2 m, as well as living thickets, to correct the crown of tilted and bent trees by shortening the trunk to a powerful shoot arising on the trunk from a dormant bud, and removing, in case of a bifurcation of the trunk, the most deflected trunk.