Improve the yield of any dung-loving mushroom species with our best-selling Boomr Bag! This sterile bulk mushroom substrate is formulated by mycologists and features a proprietary blend of composted horse manure, coco coir, and several quality substrate supplements (although we keep the exact blend a secret!) Over several years, it has been perfected for a wide range of dung-loving mushroom species and is widely-trusted by mushroom growers. Use your Boomr Bag in monotubs, outdoor beds, or to grow mushrooms from the bag in a humidity-controlled grow room or Martha setup!