Allelopathy is the chemical inhibition of one organism by another. Allelopathic effects are often observed between plant species at germination, and these interactions can be used in simple laboratory experiments to demonstrate intra- and interspecific interactions. Experiments consist of two parts: the preparation of filter papers containing the possible allelochemical and the germination of seeds on the paper to test for inhibitory effects. The experiments are simple, cheap, quick and do not use large amounts of space. As such, it is suggested that they can be used to demonstrate concepts of experimental design and statistical analysis. A possible sequence of progressively more complex experimental designs is suggested, and an example of allelopathic interactions between three germinating grass species is discussed.