Despite various challenges in the design and formulation of bioherbicides, some plant-derived herbicidal compounds have been commercially accepted. For example, the commercial herbicide cinnethylin, an analog of the natural phytotoxin 1,4-cineole, was discovered and developed by the American company Shell Chemicals [24]. Cinnethylin is a moderately effective growth inhibitor used to control monocotyledonous weeds [25]. The mechanism of action of cimmethylin is based on the inhibition of acyl-ACP thioesterases and plant fatty acid biosynthesis [26]. Triketone herbicides are derivatives of the phytotoxin leptospermone, which is produced by some members of the Myrtaceae family, such as _Callistemom citrinus_ and _Leptospermum scorarium_[27]. The molecular target of triketone herbicides is _p_-hydroxyphenylpyruvate dioxygenase, whose inhibition indirectly reduces phytoene desaturase activity, further decreasing carotenoid levels and resulting in the destabilization of the photosynthetic apparatus [28]. Recently, work has been conducted on the formulation of natural herbicides from essential oils (EOs), resulting in six such preparations being registered in the USA [29]. A major challenge in transitioning to the use of bioherbicides is the availability of suitable formulations and application methods that ensure that the biotic active ingredient is evenly distributed in the target area without wastage or overapplication, which could increase treatment costs and the risk of side effects. One of the newer approaches to improving bioherbicide formulations is through the use of nanotechnology [30]. The method of nanoencapsulation is especially suitable for small plant-derived molecules as it enhances their stability, effectiveness, and bioavailability, as well as enabling precise targeting and controlled release [30]. In light of the aforementioned issues and the increasing demand for environmentally friendly herbicides, our research group has focused on investigating the phytotoxic effects of specialized plant metabolites on selected model and target plants, with the goal of identifying potential candidates for the development of future bioherbicides. One direction of our research involves soil-exuded allelochemicals produced by plants such as the apple (_Malus \(\times\) domestica_ Borkh.) and its most prevalent specialized metabolite, phloretin [31; 32; 33; 34], while the other focuses on the effects of volatile organic compounds (VOCs), particularly those emitted from EOs from _Nepeta_ species [35; 36; 37; 38; 39; 40; 41]. The investigation of phloretin phytoxicity is based on the model species thale chess (_Arabidopsis thaliana_ ([PERSON]) ecotype Columbia, and shepherd's purse (_Capsella bursa-pastoris_ ([PERSON]), a weed species from the Brassicaceae family. The target plants included in the investigation on _Nepeta_ EOs are weed species that cause considerable yield losses in crops due to being resistant to commercial herbicides. These include common ragweed (_Ambrosia artemisinin_L. ), redroot ragweed (_Amarantthus retroflexus_L. ), and chickweed (_Stellaria media_ ([PERSON].) (International Herbicide Resistance--Weed Database, [[https://www.weedscience.org](https://www.weedscience.org)]([https://www.weedscience.org](https://www.weedscience.org)), accessed on 4 January 2025), while the selected fast-growing crops included lettuce (_Lactuca sativa_L. ), oilseed rape (_Brassic napus_L. cv. _nupus_), garden cress (_Lepidium sativum_L. ), and bird's-foot trefoil (_Lotus corniculatus_L.) (Figure 1). Here, we present recent findings on the phytotoxic effects of volatile terpen and phenolic compounds, particularly repetalactone (NL), an iridoid monoterenoid from _Nepeta_ species, and phloretin, a dihydrochalcone (DHC) predominantly found in the genus _Malus_, focusing on morphological, physiological, and biochemical responses in target plants.