[FenderSuper]

I think it is somewhat strain-dependent. I'm growing Kosher Kush in a 12x7x7 portable greenhouse and the Kosher Kush took a look at the heat and laughed. Plants are so big, the top branches are bending over. I have to get some caging to support them.

[Noonin NorCal]

I think as long as you have proper ventilation and constant air moving around you should be fine. We are running some type of Og supposed to be a fire og phenotype. The things are stretching like hell in our Solexx Greenhouse. We light dep it from 7-7. have been covering for 2 weeks now

[OregonBorn]

Cannabis is not from the equatorial zone. Cannabis is believed to originate from the Asian Steppes, north of the Himalayas to Mongolia and Southern Siberia. So it is a plant of more northern latitudes.

That said, Cannabis is an arid and heat loving plant. I have seen mine go to 115 F. no problem. The leaves are cooler than the air though. They respire water like we sweat. Water them more than normal in the heat. I like to keep my GH under 95 F., with an optimal temp of 86 F. In heat waves (over 90 F., which means over 100 F. in the GH), I put 50% shade cloth over the GH to cool it down. I also open the from door and back windows. I have never lost a pot plant to heat. Even in 110 F. heat in Gilroy, CA.

[FenderSuper]

Originally Posted by OregonBorn

Cannabis is not from the equatorial zone. Cannabis is believed to originate from the Asian Steppes, north of the Himalayas to Mongolia and Southern Siberia. So it is a plant of more northern latitudes.

That said, Cannabis is an arid and heat loving plant. I have seen mine go to 115 F. no problem. The leaves are cooler than the air though. They respire water like we sweat. Water them more than normal in the heat. I like to keep my GH under 95 F., with an optimal temp of 86 F. In heat waves (over 90 F., which means over 100 F. in the GH), I put 50% shade cloth over the GH to cool it down. I also open the from door and back windows. I have never lost a pot plant to heat. Even in 110 F. heat in Gilroy, CA.

Equatorial zone would mean, more often than not, a humid zone. The tropics. I've got massive indica fan leaves in a greenhouse, just a little north of where you are (37:30 lat) and my girls are like women from R. Crumb cartoons. Big chests, big butts, big thighs. Think "Attack of the 50-foot Woman!!!"

[OregonBorn]

Originally Posted by FenderSuper

Equatorial zone would mean, more often than not, a humid zone. The tropics. I've got massive indica fan leaves in a greenhouse, just a little north of where you are (37:30 lat) and my girls are like women from R. Crumb cartoons. Big chests, big butts, big thighs. Think "Attack of the 50-foot Woman!!!"

Well, the steppes are humid, but hardly equatorial. Or tropical. More like the 50th parallel. I am near the 45th parallel BTW. Not in Sunny CA at the moment. Though it is sunny here this summer. Perfect weed growing weather.

I had a tightly held indica strain from Mendocino growing with 18 inch long leaves here 2 summers ago. I have photos someplace... they were HUGE. Biggest leaves I have grown or seen. They were like tobacco.

I still have a collection of underground Crumb comix that I got in Berzerkeley in the late 1970s. My 1st ex identified with Crumb's big blonde that always stomped around for some reason. Maybe because she was a big blonde? I left her in Menlo Park ;(...

[acdc]

Originally Posted by OregonBorn

Well, the steppes are humid, but hardly equatorial. Or tropical. More like the 50th parallel. I am near the 45th parallel BTW. Not in Sunny CA at the moment. Though it is sunny here this summer. Perfect weed growing weather.

I had a tightly held indica strain from Mendocino growing with 18 inch long leaves here 2 summers ago. I have photos someplace... they were HUGE. Biggest leaves I have grown or seen. They were lie tobacco.

I still have a collection of underground Crumb comix that I got in Berzerkeley in the late 1970s. My 1st ex identified with Crumb's big blonde that always stomped around for some reason. Maybe because she was a big blonde? I left her in Menlo Park ;(...

indica strain from Mendocino would love to see those photos

[St. Phatty]

During the bit of heat we had this last week, it wasn't the leaves but the roots I was concerned about.

With or without a greenhouse, the soil can BAKE (depends on if you're in pots or in the ground).

I would keep an eye on the root area during the hottest parts of the day. i.e. stick your hand in there.

Long story short, my roots were water cooled this last week - 2 or 3 gallon bucket every hour or 2, in a 32 gallon pot. It would bubble a bit - and cool everything off.

I don't know what happens to nutrient up-take when the root mass gets above a 100 F/ 38 C ... but I think the grow process works better when they're cooler.

[petert]

I e had temps at close to 100 during the day for 2 solids weeks!! That was the outside temps too!! I just went inside and hosed down the weed barrier at least twice a day.. that raised the humidity and lowered the temps.
I found some Russets ( little motherfuckers) and closed the greenhouse down and let it cook between 115-120 for 60+ minutes two days in a row in July. It messed with the plants a bit.. had probably 10% leaf die off but really did a number on the russets!!

[BirdManFlyHigh]

Originally Posted by petert

I e had temps at close to 100 during the day for 2 solids weeks!! That was the outside temps too!! I just went inside and hosed down the weed barrier at least twice a day.. that raised the humidity and lowered the temps.
I found some Russets ( little motherfuckers) and closed the greenhouse down and let it cook between 115-120 for 60+ minutes two days in a row in July. It messed with the plants a bit.. had probably 10% leaf die off but really did a number on the russets!!

Did this stress cause any hermies?

[highsteppa]

Mist lines will lower temps, but you obviously won’t want them in flower