Mycorrhizal fungi are a remarkable group of organisms that have been benefitting trees for at least  500 million years

In effect the fungus provides a secondary root system, enabling your trees to extract nutrients and hold onto water better.  Mycorrhizal fungus develops naturally on trees but not for a couple of years after planting

Rootgrow introduces mycorrhizal fungus when you put it into the hole you plant the tree in

360g packet Rootgrow granules. enough for 100 cell grown trees £9.99.      2.5kg resealable tub Rootgrow granules with gel, enough for 715 cell grown trees £49.99