 The study evaluates the fungi static effect of horseradish, yarrow, and tansy extracts on selected polyphagic phytopathogenic fungi in Poland. The results show that tansy and yarrow extracts have a higher content of polyphenols and flavonoids, as well as higher antioxidant activity compared to horseradish leaf extracts. Plant extracts inhibit the growth of fungi to varying degrees depending on the species of fungus, type of extract, concentration, and duration of action. The study is a preliminary step towards developing a biological preparation for protecting agricultural and horticultural plants against fungal pathogens. This article was authored by Weronika Kursa, Agmieszka Jamiolkowska, Barbara Skwarylo Bednartz, and others.