The article analyzes the results of the influence of allelopathically active substances of plant litter and soil on the growth of herbaceous plants of the lower tier in various phytogenic zones of the maple ash-leaved. As model objects the seeds of the Melilotus officinalis and Poa pratensis were used. The study of the allelopathic effect of maple ash-leaved litter was carried out by bioassay, the soil - by experiment. In early July the seeds of grassy plants were sown in containers with soil selected under A. negundo plantations in transformed plant communities. Soil samples were taken in the subcrown and near-ground zones of the studied trees. The outer zone of single trees was chosen as a control. The biometric indicators of the test objects under study were calculated on the basis of determining the height and mass of the plants. For studies of growth parameters, a sample of ten plants was used in triplicate from each site studied. According to the results of the experiments, it was revealed that the highest rates of germination energy and seed germination in the test areas are in the M. officinalis , compared to P. pratensis . The allelopathically active substances contained in the litter and soil of A. negundo had a positive effect on the germination of the studied plants, especially in the near-front zone. Consequently, these species possess allelopathic resistance to the effects of сolin elder maple and have a positive reaction to its phytogenic zones. Probably, M. officinalis and P. pratensis, which have ecological plasticity and adaptability to living in conditions of the natural range, are determined not only by the allelopathic effect of maple root excretions, but, to a greater extent, by environmental factors in transformed plant communities. Experimental data can be used in assessing the state of the ground cover and the structure of the phytocenosis.