The reintroduction and introduction of native plant species is becoming more and more important in the restoration of plant communities. The study aimed to determine the possibility of predicting the effectiveness of the introduction of dicotyledonous species into impoverished patches of meadows in the landscape nature reserve in the proglacial valley of the Vistula River (Poland). Fourteen species planted into the soil from seedlings, after growing them from seeds in pots, in pure stands were assessed. Field studies were carried out in 2015–2017 on post-bog soil. Parameters of plant development and growth that were analysed included, among others, range, condition and height of shoots (vegetative and generative). Based on the biometric parameters, a statistical analysis (PCA, analysis of variance, decision tree) was performed. It was found that the range, i.e., the spread of the population, did not determine the classification of species into groups with a different nature of development after introduction. This classification was mainly determined by the plant condition in the following years after the introduction (over 3.4 on a 5-point scale), and the occurrence of generative shoots in the second year after planting. The group with the highest potential efficiency of introduction included three species: Achillea millefolium, Hypericum perforatum, Veronica longifolia. The failure of the introduction of other species resulted from their life form (two years old) and unfavourable weather conditions in the third year of study (2017), due to the high level of groundwater.