Heat too high for flowering?

beelstyle

Well-Known Member
Hey, my og kush is about 1 month into flowering and the temp got up to 85f without co2. I usually have my temp at 75f-80f in the winter, but the summer is around the corner and I cant seem to get the temp around that. I have ac on and still no luck. I have fans inside the grow room and the air is always moving 24/7. night temps are about 75-80. How would this effect my grow...... thanks
 

tr33hug93r

Member
I am having the same problems right now. My temps are between 75-83. I have a Jock Horror and Amnesia Auto at 6 weeks flower right now with a Somango Auto at 4 weeks flower. The only side effect that I have observed is some leaves turning yellow from heat stress as well as an increase in water intake due to a higher rate of evaporation. So in response, I have an hour off time for my 400 watt ballast while my 4 cfl's are still plugging away in the middle of my 15 hour cycle. This has helped a good bit with the temps as well as the yellowing of some leaves.
 

beelstyle

Well-Known Member
do you turn off the hps off everyday for an hour, during 12/12? when do you usually turn them off.
 

Rattsour

Active Member
I would highly advise using co2, especially if your in a basement. Ive seen such a difference since using it that i consider it a neccessity.
 

rcpilot04401

Well-Known Member
are your lights enclosed with fans? I finally got some glass to put on the housing for the lights and got 2 strong fans, and it cut down the heat drastically...you might wanna try that, and vent the heat outside of your able.
 
Plants usually adapt to there environment. Temps in the mid to upper 80's are okay. They grow outside in hotter weather than that and do fine. I would advise to keep the temps under 90 degrees F though as the plants will spend energy trying to cool off and your buds will be more fluffy in an attempt to dissipate heat.
 

zack66

Well-Known Member
Heat hurts during flowering. I quit growing in my basement during the real hot months. Colas are alot lighter and fluffier. Anything above 80 for me is too warm. I spent over 400 bucks for an a/c for my basement last summer. I blocked off everything except my 2 grow rooms and only brought the temps down 3 degrees. Raised my electric bill 75 bucks a month. Won't do it again. Good luck!
 

zack66

Well-Known Member
Plants usually adapt to there environment. Temps in the mid to upper 80's are okay. They grow outside in hotter weather than that and do fine. I would advise to keep the temps under 90 degrees F though as the plants will spend energy trying to cool off and your buds will be more fluffy in an attempt to dissipate heat.
Not aware of too many kush strains that don't mind flowering with temps in the high 80s. Outdoors yes indoors not so much. Been running lot's of kush strains over the years and none of them cared much for high temps in flower.
 
Not aware of too many kush strains that don't mind flowering with temps in the high 80s. Outdoors yes indoors not so much. Been running lot's of kush strains over the years and none of them cared much for high temps in flower.
So please tell me then, what the difference is between the temps being to high indoors but not outdoors if the conditions are consistent? I'm confused.
 

Bigby

Well-Known Member
My kolossus seems to be coping ok with an average temp increase from around 73 to about 80. I think it will spike at around low 80's for me over the summer - I don't expect any major problems with this.
 

beelstyle

Well-Known Member
My kolossus seems to be coping ok with an average temp increase from around 73 to about 80. I think it will spike at around low 80's for me over the summer - I don't expect any major problems with this.
are you going to be using co2 when temps hit 80s
 

strain horder

Active Member
Depending on what OG KUSH you are talking about, u could be ok or u could be screwed.. I have run Tahoe OG in mid 80's with no CO2 and had great results. Now if you have a closer version to the real thing like Matt Riot's OG Kush, or Raskal's OG Kush, u will probably drop every leaf on the plant and it will do terrible.. What OG Kush are you growing?
 

beelstyle

Well-Known Member
Depending on what OG KUSH you are talking about, u could be ok or u could be screwed.. I have run Tahoe OG in mid 80's with no CO2 and had great results. Now if you have a closer version to the real thing like Matt Riot's OG Kush, or Raskal's OG Kush, u will probably drop every leaf on the plant and it will do terrible.. What OG Kush are you growing?
I am growing Reserva Privada og kush , the buds seem okay, smell and everything. I grew successfully in the past and the buds look about the same. What do you mean by my leafs would drop.
 

adower

Well-Known Member
I have had my room in the mid 80's no problem. Still grow nice fat nuggs and yield a ton. Just make sure you have GOOD air circulation.
 

Fresh 2 De@th

Well-Known Member
Hey, my og kush is about 1 month into flowering and the temp got up to 85f without co2. I usually have my temp at 75f-80f in the winter, but the summer is around the corner and I cant seem to get the temp around that. I have ac on and still no luck. I have fans inside the grow room and the air is always moving 24/7. night temps are about 75-80. How would this effect my grow...... thanks
85 is kind of high, especially indoors. don't let anyone tell you any different.

my suggestion to you is, if your hood(s) has glass on it, remove it. i found that they add extra heat when they're on. if your growing in a tent, add an extra oscillating fan(s) in there.
 

Nullis

Moderator
The truth, in my experience, is that indoors the strains I have grown seem to tolerate temperatures in the 80's, up to about 88 degrees in the canopy and warmer for brief periods of time. Temperatures in the upper 80's are not favorable for ideal growth; certainly not for prolonged periods. AFAIK, at temperatures beginning to exceed 86 degrees the stomata, the pores on the leaves through which gas exchange occurs, start to close up. If the plant isn't exchanging gases (oxygen, CO2) then it isn't photosynthesizing. Stoma need to be open in order to get CO2 and while they are open, water is being lost (evaporating). So in order to conserve water in the heat the stomata close up. Supplementing carbon dioxide opens stomata to compensate for higher temperatures.

Otherwise circulation is extremely important to facilitate gas exchange and dispose of heat. Summer time is the worst for growing indoors. I would suggest considering air-cooling for virtually any HID lighting. It is simply more efficient to remove as much heat as possible from the source with a fan that uses maybe 150 watts versus a thousand or more. You still may need to use an AC with cooled reflectors, especially with multiple lights. My two reflectors are sealed, and air cooled with a 6" HO ventilation fan (with carbon filter) that is drawing air from inside the tent. There are 2x600 watt HIDs, still need to use the air conditioner in the summer, with temperatures between 78-87 with lights on lately. I have a Kandy Kush under one of the lights and it seems to be doing just fine, with buds growing about 5" from the lamp.

So please tell me then, what the difference is between the temps being to high indoors but not outdoors if the conditions are consistent? I'm confused.
Outside plants have access to an open atmosphere of carbon dioxide. It is still likely their stomata are closing up during peak temperatures, assuming they are in full sun in temperatures over 90f.
 
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