Humboldt Nutrients' White Widow is a Mycorrhizal powder containing a diverse concentration of mycological spores for unprecedented root development. It's a diverse, pure endo Mycorrhizal in a super-fine, highly soluble powder for maximum effectiveness. Whether it's used in soil or hydroponic gardens, White Widow is a must-have for gardeners concerned about the quality and health of their plant's root system. If you can keep things healthy on the surface, Humboldt Nutrients White Widow will handle the situation underneath.