How cold is too cold?

[DrDoob]

I have plants in all stages from seedlings and clones to 7 weeks into flowering. I’ve never had to deal with cold before. It’s been getting down to the high 40s at night but into the high 70s and 80s during the day. I read that the cold nights will slow development of vegetive plants but what about flowering? How cold is too cold?

 

[Bonsaiweed]

70 Degrees is the temp that usually stunts growth of a cannabis plant. Any lower, and you risk problems.

The actual temp which causes effects will depend on the plant health and strain.

 

[DrDoob]

70 Degrees is the temp that usually stunts growth of a cannabis plant. Any lower, and you risk problems.

The actual temp which causes effects will depend on the plant health and strain.

They are in tents in an uninsulated garage, so controling the temps is tricky. They are all healthy looking and seem fine, does the cold slow down flowering or just vegetive growth? The cold nights are bringing out a lot of color, and don’t seem to be causing any real problems. I have too many so if my veg plants slow down a bit it’s good, but if the flowering plants take much longer to mature then I’ll run out of space.

 

[Itibitiguy]

Hey Drdoob
My setup is in an unheated area too... I use a oil filled radiation heater, and cover up your tent with some old blankets... hit the thrift store. I think once you get under 10c they stop growing.

 

[Oldbear]

Have you considered running the lights at night?

 

[Itibitiguy]

Have you considered running the lights at night?

Good call oldbear. I do run my lights at night forgot to mention

 

[DrDoob]

Have you considered running the lights at night?

Thanks, that’s a good idea! I used to do that in the summer, ironically due to too much heat during the day. Buy I’ve since had solar panels installed and I can’t afford to lose the cost savings.

I bought some thermometer controlled plugs for the fans and have some blankets ready, like Itibitiguy suggested, but I think it was just a cold stretch. It only got to 57° last night. I was just overly concerned, and trying to prepare. It hasn’t seemed to slow anything down. It really brought out some nice colors on the flowering plants too.

 

[Bonsaiweed]

The purps usually show when cold extremes happen.

 

[Itibitiguy]

My tents looks like I made 2 blanket forts

 

[DrDoob]

I spoke too soon, last night was the coldest in years. The blankets really helped, thanks for the tip @Itibitiguy ! The clone tent only got to 59° which I think is fine as the overnight low.

I’ve tried to research how much cold slows ripining of buds but finding good info hasn’t been easy. Most just say it slows vegetive growth, these plants aren't really growing just at the last stage of ripening. Most info I find about flowering and the cold talks about not letting them freeze and about how cold nights being out the colors (they sure do!).

 

[millertm]

My hardstop is 60, I too, am in a garage but I'll through in a small heater during the day to keep it at 60. Just started flowering this week. I was vegging 24 hours due to how cold its been. My plants are fine at 60 lights out, 77 lights on.

Cheers

20180227_080759.jpg

• millertm
• Feb 27, 2018

 

[Bonsaiweed]

Glad the blankets worked. Was a great suggestion. Wish I had thought of that.......

 

[FelipeBlu]

Thanks for this thread. My tent is in an uninsulated garage too, and my temps have not gotten out of the mid to upper 60s for a couple of weeks now. I’m running 24 hour lights also. The purple colors are coming out in buds and the top side of stems, but otherwise, the plants appear to be growing at a fairly normal rate.

Love the suggestion of covering the tent with blankets! Thanks!

Does anyone know if Autos are more tolerant of cooler temps due to the ruderalis genetics coming from above the Arctic circle?

 

[DrDoob]

Well the cold didn’t seem to slow anything down much. I just harvested two that were flowering and they took just a couple days longer then the last batch of the same clones. And the clones I moved in to replace them vegged normally as far as I can tell.

I don’t know if autos do better with the cold, but now you got me thinking. It would be cool to grow little autos outside year round. It almost never gets below freezing at night, so I could probably do it.

 

[FelipeBlu]

Well, I ended up giving up on the cold and damp garage. Have the tent upstairs now. Traded 57F/74% for 78F/44%. Ahhhh...

Actually, I was more nervous about the humidity than bothered by the cool temps.

San Diego would be ideal for winter Autos outside. I think we get too much rain up here.

 

[Bonsaiweed]

Well, I ended up giving up on the cold and damp garage. Have the tent upstairs now. Traded 57F/74% for 78F/44%. Ahhhh...

Actually, I was more nervous about the humidity than bothered by the cool temps.

San Diego would be ideal for winter Autos outside. I think we get too much rain up here.

That 44% will be nice for flower though.... A little low for seedlings.

 

[FelipeBlu]

Yeah, flowering is where I’m at, so I’m happy.

 

[Stltoed]

I have plants in all stages from seedlings and clones to 7 weeks into flowering. I’ve never had to deal with cold before. It’s been getting down to the high 40s at night but into the high 70s and 80s during the day. I read that the cold nights will slow development of vegetive plants but what about flowering? How cold is too cold?

Seems like too cold will be when your plant turns into a floor mat. Ive been in the high 50s trying to make my Ayahuasca Purple, purple with no problems. My little room is pretty well insulated. Did you see any color change? I couldn't afford to run the air that cold for a long period of time.

I felt like a shmuck for rousting you for not popping in, so i popped in. Cheers

 

[DrDoob]

Seems like too cold will be when your plant turns into a floor mat. Ive been in the high 50s trying to make my Ayahuasca Purple, purple with no problems. My little room is pretty well insulated. Did you see any color change? I couldn't afford to run the air that cold for a long period of time.

I felt like a shmuck for rousting you for not popping in, so i popped in. Cheers

I did get a lot of purple that run. Lol I don't even have a journal right now so no shmuckism there.

 

[Stltoed]

I did get a lot of purple that run. Lol I don't even have a journal right now so no shmuckism there.

Purple is good. You must be rollin around in bud right now. Can i talk you into a forum. I promise not to be a smuck