Vegetable production and processing biowaste as well as vegetable postharvest by-products are disposed of. These wastes contain a wealth of beneficial phytochemicals. Consequently, it stimulates scientific curiosity to investigate the phytochemical composition of these by-products and attempt to determine their possible uses. A common deficiency in knowledge is the precise phytochemical makeup of each kind of by-product derived from vegetables. The most crucial elements for conducting consecutive in vitro and in vivo investigations in the field are not entirely agreed upon or commonly accepted. The variety of bioactive chemicals obtained by various authors frequently complicates comparisons. Botanicals’ uncertain safety profile may complicate their application, and more toxicological data are required to support this. This work highlights the current situation and valorization potential of bulb, flower, and fruity vegetable by-products.