Heat temperature in flowering and vegetation room

[Oldschool61]

I've been reading on different forums. Everybody has their own opinions. People arguing 85° too hot in grow room. NoT. I run my vegetation 85°, humidity is about 60 ,58%. No problems. So why are people telling young growers, that you need to bring your temperature down. If you go past 90, well, can you stand 90° heat for 18 hour, no, But ,you can withstand 85 with a breeze can you not?????? I'm just asking the question????? Unless you see that plant heat stressing, yeah you need to bring the heat down.

 

[elduderito]

While your plant may not show signs of heat stress it still may benefit from lower temperatures - higher temperatures can lead to loss of terpenes, slower growth, and increased susceptibility to pests... Just because your not having problems does not mean that your results would not improve if you made some changes.... it's also notable to mention that veg phase can tolerate higher temps, it's during the flower phase that you will more likely see the difference in performance...

 

[Aqua Man]

Spoiler alert.... air temps are not nearly as important as leaf and plant temps. Some LED grows can have a 10f difference between air temps and leaf temp.

Many factors contribute to this and while air temp is one of them imo it's not accurate to judge what's ok for the plant and what's not.

 

[Oldschool61]

While your plant may not show signs of heat stress it still may benefit from lower temperatures - higher temperatures can lead to loss of terpenes, slower growth, and increased susceptibility to pests... Just because your not having problems does not mean that your results would not improve if you made some changes.... it's also notable to mention that veg phase can tolerate higher temps, it's during the flower phase that you will more likely see the difference in performance...

I run my flowering room at 73°, with a 56 to 57% humidity. Vegetation stage is just growing the burgers. Flowering stage is where everything pops!!

 

[elduderito]

interesting - I think I read another of your posts about this - could you point me to more info or provide some more details on ideal leaf temperatures ? I guess i need an infrared thermometer...

 

[Oldschool61]

Spoiler alert.... air temps are not nearly as important as leaf and plant temps. Some LED grows can have a 10f difference between air temps and leaf temp.

Many factors contribute to this and while air temp is one of them imo it's not accurate to judge what's ok for the plant and what's not.

I'm having no problem in vegetation I've been growing for 3 months. no probs. I have to keep them in bed that long because my flowering room is packed!!

 

[Oldschool61]

interesting - I think I read another of your posts about this - could you point me to more info or provide some more details on ideal leaf temperatures ? I guess i need an infrared thermometer...

I just researched ask,crazy questions. Most of it is from trial and error. I've read a lot online by the forums. Lot of contradictions. I read a lot of people between 70 and 80° is the ideal temperature. Now if I see my Lee's wrinkling or look like they're stressed by the heat I raise my lights. They're going to grow no matter where your lights are in vegetation. I've been gone for about 5 years I've lost crops I've screwed up!!! But I'm there now

 

[Oldschool61]

I just researched ask,crazy questions. Most of it is from trial and error. I've read a lot online by the forums. Lot of contradictions. I read a lot of people between 70 and 80° is the ideal temperature. Now if I see my Lee's wrinkling or look like they're stressed by the heat I raise my lights. They're going to grow no matter where your lights are in vegetation. I've been gone for about 5 years I've lost crops I've screwed up!!! But I'm there now

Half the time this phone can't understand this country boy

 

[Aqua Man]

Ideal leaf without co2 are 75-77f but 70-80f usually has no issue... very quickly above 80f you will start to see stress.

I have a VPD thread that touches on some of it.

VPD (vapor pressure deficit)

Ok i was gonna sit down and write out a whole article but i have been lazy so instead instead I'm going to copy paste because im lazy. This is not my work so let start. You may find this very long but its worth the read. Some may want to skip ahead. I have added here and there to what i feel is...

www.thcfarmer.com

 

[Oldschool61]

Ideal leaf without co2 are 75-77f but 70-80f usually has no issue... very quickly above 80f you will start to see stress.

I have a VPD thread that touches on some of it.

VPD (vapor pressure deficit)

Ok i was gonna sit down and write out a whole article but i have been lazy so instead instead I'm going to copy paste because im lazy. This is not my work so let start. You may find this very long but its worth the read. Some may want to skip ahead. I have added here and there to what i feel is...

www.thcfarmer.com

 

[Oldschool61]

I agree what you said temperature can mess up a plant. I've used CO2 in the bedroom and the flowering room. Used to make homemade CO2 generators. Too much trouble keeping a CO2 in there all the time too expensive if you buy setup. My weed knocks you on your butt without CO2

 

[Aqua Man]

With your airflow increasing forced evaporation I'd say it's highly likely your leaf temls are right in the target range. I run my room very close to that te.p also until late flower

 

[Aqua Man]

Remember room temp and leaf temp are very different some can run high 80s and see no heat stress and good leaf temps

 

[Oldschool61]

Remember room temp and leaf temp are very different some can run high 80s and see no heat stress and good leaf temps

Send me some details of information on what you're telling me. If you would

 

[Oldschool61]

Send me some details of information on what you're telling me. If you would

I like to read

 

[Aqua Man]

Here is one... off to bed as I have aboit 6 hrs of sleep left before I'm back at it. Some of the values are higher than I said but this is sativa and they generally can tolerate higher temos better.

Temperature response of photosynthesis in different drug and fiber varieties of Cannabis sativa L.

The temperature response on gas and water vapour exchange characteristics of three medicinal drug type (HP Mexican, MX and W1) and four industrial fiber type (Felinq 34, Kompolty, Zolo 11 and Zolo 15) varieties of Cannabis sativa, originally from different ...

www.ncbi.nlm.nih.gov

 

[Aqua Man]

Photosynthetic response of Cannabis sativa L. to variations in photosynthetic photon flux densities, temperature and CO2 conditions

Effect of different photosynthetic photon flux densities (0, 500, 1000, 1500 and 2000 μmol m[−2] s[−1] ), temperatures (20, 25, 30, 35 and 40 °C) and CO[2] concentrations (250, 350, 450, 550, 650 and 750 μmol mol[−1] ...

www.ncbi.nlm.nih.gov

Scroll down to full text and click on pdf.

 

[Oldschool61]

Photosynthetic response of Cannabis sativa L. to variations in photosynthetic photon flux densities, temperature and CO2 conditions

Effect of different photosynthetic photon flux densities (0, 500, 1000, 1500 and 2000 μmol m[−2] s[−1] ), temperatures (20, 25, 30, 35 and 40 °C) and CO[2] concentrations (250, 350, 450, 550, 650 and 750 μmol mol[−1] ...

www.ncbi.nlm.nih.gov

Scroll down to full text and click on pdf.

That's a long read I understand temperature CO2 air flow water evaporation take it in water with the leaves. Now these articles are high dollar outfits with ideal conditions. Now as we all on this forum or home growers. Most the people on here can't afford all what you're saying to put in their rooms. It took me 2 years to get my room set up. Now if I was rich and a chemist. I wouldn't have to go in them rooms everyday. I was raised on the farm been working on one since I was 12 years old. Things we use to make plants grow you would not believe. And you know if, doing everything you supposed to as best as you can. And the outcome of your product. Put you on your ass! Well then I think you done pretty well!!!!

 

[Aqua Man]

That's a long read I understand temperature CO2 air flow water evaporation take it in water with the leaves. Now these articles are high dollar outfits with ideal conditions. Now as we all on this forum or home growers. Most the people on here can't afford all what you're saying to put in their rooms. It took me 2 years to get my room set up. Now if I was rich and a chemist. I wouldn't have to go in them rooms everyday. I was raised on the farm been working on one since I was 12 years old. Things we use to make plants grow you would not believe. And you know if, doing everything you supposed to as best as you can. And the outcome of your product. Put you on your ass! Well then I think you done pretty well!!!!

I'm not saying they should do anything.... just sharing information based on facts not broscience. I was simply stating that leaf and air temps are not the same and when you asked for me to provide reading to back up my claims I provided it.

Cannabis can grow in a wide variety of conditions no doubt... but that dosen't make them optimal.... and I agree is the cost worth the gain? Depends who ya ask but personally in a lot of cases nope I don't think it is. But its never a bad thing to strive for optimal and thats hard to do without knowing what optimal is

 

[Oldschool61]

This is one of my end products. This is either lemon Haze or strawberry breath. I have PTSD anxiety from the Gulf war. This stuff works for me man. Puts my ass to sleep.