Plant competition is one of the most crucial factors in a plant communities, along with resources, grazing, disturbance and mutualism. Think about it, a plant needs a few basic accommodates in order to sustain an adequate life. Those accommodates include light, water nitrogen or phosphorus depending on that plant’s needs.
Keeping that in mind how might we find undesired plants or weeds to be a disturbance in our garden? When you allow harmful undesired organisms to thrive near your desired crop then you may find the desired plants lack in nutrients. Some weeds might even be poisoning your plants! A weed called nut grass, for instance, have chemicals that are released from their roots that are harmful to surrounding plants.