Effect of Plant Seed Mixture on Overwintering and Floristic Attractiveness of the Flower Strip in Western Poland

In order to increase biodiversity in cultivated areas, the implementation of agri-environmental programs is proposed, including interventions and eco-schemes. Flower strips are one such proposal. In order to achieve satisfactory results, the appropriate selection of plants is crucial. In flower strips, the number and diversification of overwintering plant species are important. Our observations suggest that the species diversity observed in the second year of the strip’s presence in western Poland composed of mostly annual 14 plant species did not overlap in the next year. The flower strip was established on soils in a very good rye complex. The average monthly air temperature in both seasons was similar. In the winter months after the establishment of the flower strip, the lowest temperature at the ground level and the lowest air temperature were recorded in December (−5.4 °C and −13.7 °C, respectively). Hydrological conditions were not favorable, including a very dry March. Wild species originally from the soil seed bank were dominant. The selection of the appropriate species composition of mixtures intended for flower strips should take into account not only the preferences of beneficial insects but also environmental conditions. The possibilities of the selected plant species are important. A large variety of spontaneously emerging species (considered weeds) can also successfully colonize existing gaps in the flower strips, providing an increase in biodiversity. From the beginning of June to the end of July, the share of flowering plants from the seed bank ranged from 42.59% to 88.19%, while among originally intended plant species, it was only 11.81–57.41%. In May and at the beginning of June, two intended species that were intensively flowering, Trifolium incarnatum L. (over 70.5%) and Phacelia tanacetifolia Benth. (26.47%), were definitely dominant. In later observations, it was noted that, unfortunately, the sown plants had a low level of flowering compared to the wild plants found in the flower strip. It is very important that flower strips include species that also bloom in July and August, and wildflower plants can highlight the attractiveness of the flower strip to beneficial insects and are a valuable addition. This paper evaluates the suitability of a commercially available seed mixture in terms of the floristic attractiveness and overwintering potential of annual plants.