Indirect Light While mushrooms do not need light to grow, shocking them with light will trigger pinning. Do not use direct light as this will dry out your mushrooms and make them shy. Indirect light, such as on a shady windowsill or from a nearby LED lamp, is enough to encourage mushroom growth. High Humidity During the fruiting stage, mushrooms require a far higher humidity than during incubation—almost 80-90% humidity. This is important because your mushrooms will not grow if there is a risk of them drying out. Ensuring a high humidity will relieve this issue.
