RHS endorsed. Rootgrow is the best value plant treatment you will ever buy. With just one application of rootgrow at planting time, your plants will develop a huge secondary root system supplying nutrients and water for their entire lifetime.Mycorrhizal fungi are a remarkable group of organisms that have been benefiting plants for 500 million years.At the dawn of time when plants were just beginning to colonise our planet mycorrhizal fungi were there living in a symbiotic relationship with plants. They became a secondary living root system that enabled plants to extract nutrients and hold onto water in very difficult soil conditions.As plants evolved so did the mycorrhizal fungi, the more developed forms that associate with large woodland trees evolved fruiting bodies (mushrooms) as a means of dispersing spores into the air. Some of these mycorrhizal mushrooms such as Truffles, Chanterelles and Porcini are prized in the kitchen for their culinary value.