The rapid breakdown of carbohydrates in seaweed stimulate beneficial soil bacteria that produce nitrogen and make it available to plant roots. Plants have a greater resistance to environmental stress, resulting in reduced damage from early frost. When applied to plants as a foliar spray, less damage is sustained in extreme heat and drought conditions. Fruits and vegetable have a greater nutritional value, including all animal feed crops. Plants have more complete and extensive root systems, resulting in healthier foliage and fruit appearance.
Plants have a greater resistance to nematodes, fungal disease and pests.
Seaweed promotes better chlorophyll production in plants and contains within its struture and composition several plant growth hormones. Some scientists believe that seaweed has developed anti-toxins to fend off bacteria and viruses in the ocean. In the garden these anti-toxins interrupt the reproductive cycle of some insects, and appear to repel others. Seaweed also reduces fungi when applied to plants or soil. In tests at the University of Maryland, seaweed meal reduced soil nematodes in turf grass plots.