When do you think it is too cold in the grow room? I don't normally have problems but I am growing inside my house in my basement where it's really cold, I do have heat down there but it's normally very cold, lights on its 70-72 and lights out normally 58-60 but it has dropped to 55 this week as it's been so could outside, I'm currently flowering and I am 15 days into it, everything looks good no plants look bad at all, I am also running a dehumidifier now to lower the hum and also increase the heat of the room without having to run a space heater that doesn't really heat much anyways, what's your thoughts on this, will my yield lack any? I've had previous very cold runs and have had a few plants have issues, I'm currently growing about 20 different strains all from feminized seeds
The answer to this is strain specific, as above^^^, an indica is more cold tolerant than a sativa, as for hybrids, grow them as for heat loving sativas, because once temps fall out of the zone, either too hot or too cold the plant falls dormant until the desired temp returns, meanwhile mold has a party.
Over the years I've been studying this closely, and until I learn anything different I see it this way.
There are 2 temps the air temp, and the root or soil temp, once the soil temp has fallen too cold real shit can happen, but this really depends on the genetics of the plant whether it continues or not, cold air temps, below 6c/54F can be tolerated for a few hours but so long as the soil temp is tolerable the plant will live ..the same with too hot, anything above 30c/84F, the plant sleeps
it was easier for me to allocate zones to my temps
20c-30c 64f-84 green zone .. good
10c-20c 45f-64f yellow zone .. poor
0c-10c 32f- 50f red zone ... danger
these are air temps as in most cases the soil temps are a few degrees warmer than the air
one clue can be the red leaf stems, red leaves or main stalks that can give an indication of room temps being too cold
good luck