Traditional methods used to increase plant productivity from the past to the present cause problems owing to their toxicological effects on organism resistance and living things. This has stipulated the creation of strategies to boost plant productivity without adversely affecting the health of living things. Essential oils secreted from various parts of plants stand out as, sustainable, and improvable alternatives and have been the subject of numerous types of research as they have many functional properties. The present research covers the investigation of the allelopathic effect of essential oils of Greek Oregano (Origanum vulgare L. subsp. hirtum), Lavandin (Lavandula x intermedia), and common sage (Salvia officinalis L.) on oilseed plants (Cephalaria syriaca L., Camelina sativa L.) at different ratios. Inhibitory effects of the essential oils obtained by hydrodistillation on the seeds of Cephalaria syriaca L. and Camelina sativa L. species at different concentrations were analyzed under sterile in vitro conditions. The inhibitory effects of essential oils and concentrations were analyzed using the Friedman test. The research revealed that essential oils were effective in weed control through their high inhibitory effect against Cephalaria syriaca L. seeds while reducing the germination power of Camelina sativa L.