Lowest possible temps you can grow MJ in?
Couldn’t tell you exactly, but my attic regularly gets into the high 40's and I guess possibly even the 30's a couple nights or weeks of the year, 55-75+ during the day, (48 right now in there at 9pm) it’s 41 degrees outside getting down to 34 before a high of 50 tomorrow (that is 7 and 4 degrees lower respectively, than the average for this month), and I'm flowering early right now at 12” tall just in a soil pot with lights and an oscillating fan as an experiment, so I'll let you know.
I know, I have read all the articles and opinions saying it stunts the production and the stress is too much for the plant and they are all probably absolutely right. But, nature is nature. This IS just a weed and that's a GREAT thing! I have had 4 incredibly successful personal grows for 3 straight years up there with this exact same setup and temps, save for the fact that all the previous grows were done in a tiny little Aerogarden. It was my first 4 attempts ever, but I was thoroughly amazed that I got three to four, 3'+ tall plants in that little hydroponic bowl, and so was the guy who turned me onto it!
(Under 4' was due to the limitations of my space, not the possibilities in cold).
This was of course after I disconnected the grow lamp from the arm on the base and screwed a mount I made for it higher up to the side of my attic wall. (This allowed the plants to get over 3’, because that’s all the cord length I had at the time, which I have since solved, but also they were bulging out of the little holes in the Aerogarden base and I don’t know how much taller it could stand) I only added 4 clamp on lamp bulbs on the sides to the stock main light on it. Nothing else.
I'm here to tell you they were the some of the most beautiful, High Times-worthy buds I have ever smoked, and the plants were all packed with thick, dense, red and purple hairs all crystalized together in picture perfection. Very high yield for the size plant sizes I'm talking about. I have higher hopes for this soil experiment. Point is, it's very possible as long as you have the oscillating fan on 24/7 and it doesn't go below freezing for too long, but I believe our outdoor temps got into the teens for a week on one of those grows. These plants grow wild in the mountains in California, and it gets almost freezing a lot up there.
Of course outdoors are easily bigger yields, and it may not be the perfect environment up there, although I would argue bug control in the south is an illusion and, combined with humidity and mildew, has cost me more in product than I’ve gotten from outdoor stuff this year, (1st attempt here, but not impressed) so for those reasons I prefer the relative control over those things that I have up there. I can only grow up there from the beginning of November to maybe early May, so only two good full grows per year. After that then it’s regularly in the high 90’s to 105+ up there and humid, the fan doesn’t control that well enough, and the heat is just too much.
In summary, I think as long as you can get into the 50’s or better during the day and not go too close to freezing, too cold may be easier to grow in than too hot, at least where it’s humid in my experience.
Hope that helps someone.
otherwise ill do what he does
same climate... Maine. Tangerine dream 
/hug
