The most important factor when applying any mycorrhizal inoculum is to make sure that the mycorrhizal product touches the roots of the plant. This ensures that the spores (seeds of the fungus) touch the roots and germinate. Plant Success Organics Soluble can be watered into the root system of established plants or at transplant time Plant Success Organics Granular can be spread around the root ball. Specific application rates can be found on our product pages.