I can't answer that. I don't have those problems. Generally a healthy plant is more resistant to infestation. Compost will do that. I'm not saying that it doesn't have any good qualities, only that these qualities can also be found in cheaper more local amendments. When I see kelp on the beach, there's nothing growing in it and it attracts a lot of flies. Iceplant grows up on the dunes with little else. Other than the waves wiping out the beach area, according to theory, this area should be a jungle of huge overgrown vegetation. It just doesn't happen.I thought kelp also helped with disease suppression and insects as well as other good properties (secondary metabolites). Is that wrong?