With the aim of evaluating the antigerminative activity of plant extracts, a miniaturized assay using 96 well plates (WP assay) was developed and compared to the long-established assay using Petri dishes (PD assay). The WP assay yielded results comparable to those of the PD assay using an ethanolic extract of the Himalayan balsam and lawsone as a standard. It also allowed the needed volume of the test solution to be cut by half and the number of required cress seeds to be cut by more than 1.5. The WP assay was then successfully applied to various extracts of Himalayan balsam, molecules (2,4-D, glyphosate and 2-MNQ) and target seeds (radish, lettuce, and wheat). By being adapted to 96 well plates format, the antigerminative WP assay is a promising alternative to the PD assay. Besides, its convenience and low resource consumption make it ready for accelerated and high throughput screening, as well as automation.