5.5 lbs Second generation mushroom spawn 100% clean, full of mycelium Blue oyster can be grown outdoor and indoor spawn shelft life is up to 6 months if refrigerated mushroom spawn, second generation. Blue oyster mushrooms are a type of mushroom that thrives in cold weather and can be grown either indoors or outdoors. If growing outdoors, they tend to do better in early spring or late fall. Indoor cultivation requires the temperature to be maintained below 70 degrees Fahrenheit for optimal growth.