quebec gold finishes outdoors around second-thrid week of october, yes they are cold resistant but the 39 in it makes it start flowering late in the season which makes them grow slower due to temp dips at night and the less intense sunlight of the later fall.... i can advise that growing freezeland rather than m39 or quebec gold is alot better.
freezeland is very mold resistant and finished around the 23-27 september in quebec.
m39 grows super compact and can yeild alot but you need a nice season to make it worth it. it finishes around october 20th.
and quebec gold finishes around the 15-20th october,
i grew 100 m39 and harvested 7lbs, in the same spot i grew 44 freezeland the year before and harvested 8lbs. nice seasons both years just that 39 isnt as good of an outdoor strain..same for quebec gold..
i advise to grow straight freezeland over anything else. i can post pics of the crappy 39 season i had if anyone wants to see..