Soil fungi known as mycorrhizal fungi make vital contributions to plant and soil health. Mycorrhizae simply means, "root fungus," and refers to fungi which live in close association with the root systems of plants, extending out from the plant's own roots. By nurturing and, where necessary, re-introducing mycorrhizal species, plant growth is enhanced.
Mycorrhizal fungi live in and around the root zone of plants, extending far out from the plant's roots with their own network of thread-like filaments known as hyphae. This greatly extends the effective surface area of the plants roots. Mycorrhizal fungi are particularly vulnerable because they can multiply only while living on the root system of a host plant, and so they cannot survive long in bare-soil conditions. Nor can they thrive in conditions where soluble fertilizers have been used continually for many years.