<p>Research now focuses on plant extract’s allelopathic properties due to rising interest in their bioactive compounds. Aqueous extracts from small burnet (<i>Sanguisorba minor</i> L.) leaves, shoots, and roots were tested for allelopathic effects on germination and seedling growth of canary grass (<i>Phalaris canariensis</i> L.) and flax (<i>Linum usitatissimum</i> L.). Many parts of the world have recognized this edible plant as a safe food option. To determine the impact of the extracts, in vitro experiments were conducted with different concentrations. The results showed that the aqueous extracts significantly reduced germination, root length, and shoot length by acting as efficient, dose-dependent inhibitors. Notably, leaf extracts exhibited the highest inhibitory effect compared to shoots and roots. Canary grass demonstrated the greatest sensitivity to the extracts. Concentrations exceeding 20 g L⁻¹ led to significant inhibition (<i>p</i> &lt; 0.05) of all measured traits, with variability observed between species. Using colorimetric analysis, it was discovered that the leaves and roots contained the highest amount of phenolic and flavonoid, with (2.37 and 1.73 mg GAE/g dry weight) and (3.30 and 2.14 mg QE/g dry weight) respectively. Through its phytochemical properties, <i>Sanguisorba minor</i> can be used as a natural herbicide, and these findings demonstrate its potential.</p>