There is 'white fuzzy stuff' growing on the stipes of my mushrooms...
If the conditions are somewhat too moist at the point where mushrooms enter their last fruiting stage, some mycelium can grow on the stipes.
If the conditions are somewhat too moist at the point where mushrooms enter their last fruiting stage, some mycelium can grow on the stipes. Generally this doesn't do any harm. You can try to lower the humidity a bit by providing more fresh air, but in general the condition isn't something you should be too concerned about.
