The ecto- and endomycorrhizae in Rooters Mycorrhizae are specially chosen for their ability to thrive in a multitude of environments, so no matter where plants grow, the mycorrhizae will provide the root and growth benefits for which they're known. Using Rooters Mycorrhizae with an organic fertilizer ensures maximum development and plant utilization of the mycorrhizae. Application: One teaspoon of Rooters per gallon of soil.