Maybe you could speak with the landlord and see about getting the roof fixed but that looks like a big job to undertake. The mold doesn't look to be caused by growers to me but by a bad roof with completely saturated sheathing. How does it smell? Insulation soaked too? Is this the whole area or just where the ice dams form on your roof? That is potentially a massive job if all the trusses are shot too.
I spoke with the landlord a few days ago and he wants to get it fixed but I don't know if he really understands the severity of the issue, he wants to run an ozone generator, brush off the dead mold, and seal with an anti mold paint, but that's not gonna be the solution i don't think, may mask the problem temporarily...but not for long. The people in this thread have been extremely helpful in sharing their thoughts on the severity of the problem.
I found out that a grower around a year ago, was running all of his exhaust directly into the attic so that probably did the trick.
it doesn't smell at the moment, the insulation is not soaked or wet (**as of today that it, but its not cold right now, can report when i check on a colder day), the mold is heavier concentrated on ice dam areas but there are signs throughout the whole roof. For what it's worth, maybe 1/3 of the attic space is above the grow room, another 1/3 is over stair/hallway space and then the final 1/3 is over another bedroom across the hall from the grow room, I notice that the mold is basically equally concentrated in the space above the grow room as it is in the space above the bedroom. Not that that does much but it makes me wonder if the grow is what's causing the issue, potentially poor insulation above each room. certainly the venting into the attic would cause this sort of thing to happen but for it to be equally concentrated on two far ends of the attic and not as bad in the middle, makes me wonder a bit.