How is cannabis able to take high temps outdoors in summer, but not indoors?

  • Thread starter wowzerz
  • Start date
  • Tagged users None
W

wowzerz

29
1
A buddy of mine asked me why cooling was such a big deal in the grow room, his point was that outdoor plants do fine in the summer heat. I had no idea how to answer that, never thought about it.
In my area it gets 100 and above quite frequently in the summer, but plenty of people grow herb and do fine. If it were to reach 100 in my room my plants would die, how is this? I have a feeling it has something to do with light intensity but I'm not sure. I tryed goggling this with no luck.
 
E

EduardoSanchez

6
1
how about the temp of your roots also being 100. totally not cool. the ground never gets that hot 2 or 3 inches under the surface. another thought.....it only stays hot for a peak of the day not 1 hour after your lights heat up, to lights off. making any sense?
 
W

wowzerz

29
1
I thought about the root temp. But I keep a chiller in my rez, and lots of other people do as well.

As far as the duration of temps. I have bee told by many growers that even a very short time of high heat will stunt plants indoors.
Thanks for the reply.
 
M

mdTHC420

235
0
it may get how outside, but there is still a shit ton of air moving around the plants outside. indoors high temps usually result from poor room design; ie poor venting, no air flow, high humidity, ect, and in no way mirror the environment of outdoors you are trying to create. indoors the point is to have an optimal environment with temps in control; who really wants a 100 degree grow room because it can happen outside. 2 entirely different ways of growing that have little to do with one another in technique and practice.

ps: weed doesnt grow in hydro naturally
 
TrichromeFan

TrichromeFan

1,850
83
High heat promotes stretching indoors which can be very bad depending on grow area and style. It also is not within the optimum growth temps. One of the benefits of being indoors is the ability to control these factors in order to optimize growth. I have had plants hit 100 indoors before in a non ac grow. They did not produce as much as my cooler climate crops. In fact, I had a 2 level flower chamber with 600's. The top chamber always was 7-10 degrees higher than the bottom chamber. Because of that, the bottom always produced more weight, all other factors being identical.

-TF
 
P

paulycali

2,479
163
Co2! More oxygen the better the growth. Plus morning dew. Also plants are sprayed with water a few times a day when heat is high to help cool them off. Lots of air movement in and around the plant from the wind also helps keep them cool
 
W

wowzerz

29
1
it may get how outside, but there is still a shit ton of air moving around the plants outside. indoors high temps usually result from poor room design; ie poor venting, no air flow, high humidity, ect, and in no way mirror the environment of outdoors you are trying to create. indoors the point is to have an optimal environment with temps in control; who really wants a 100 degree grow room because it can happen outside. 2 entirely different ways of growing that have little to do with one another in technique and practice.

ps: weed doesnt grow in hydro naturally
I don't want a 100 degree grow room either. I know that it grows better with lower temps in my grow room. And I know if I let my temps get over 80-85 my plants would suffer ( I run my room @78 with co2 fyi).
My question is WHY. Why can they take those high temps outside, and thrive?

High heat promotes stretching indoors which can be very bad depending on grow area and style. It also is not within the optimum growth temps. One of the benefits of being indoors is the ability to control these factors in order to optimize growth. I have had plants hit 100 indoors before in a non ac grow. They did not produce as much as my cooler climate crops. In fact, I had a 2 level flower chamber with 600's. The top chamber always was 7-10 degrees higher than the bottom chamber. Because of that, the bottom always produced more weight, all other factors being identical.

-TF
as said above, I understand that no one would want temps that high indoors. Question is why can they take that heat outside.

Plants can thrive like was said above becuase the rootzone outdoors does not get up that high:cake
As said in earlier post, plenty people use a chiller (I'm one of them) you would still not be able to run temps that high, so I'm not sure if that could be it.

I have heard a few reasons.

rootzone temp

VPD vapor pressure deficit. Its a balance between heat and humidity

heres a link to a lengthy post on it
https://www.icmag.com/ic/showpost.php?p=3659553&postcount=4
as said above, even with chillers(keeping the roots nice and cool) I dont think they could take the heat.
Thank you for that link, I am going to read now!!
 
motherlode

motherlode

@Rolln_J
Supporter
5,524
313
I know somebody whos room hits 95 pretty constant in the summer

his summer harvests yeild more bud and better quality then his winter grows
 
Mega grow 215

Mega grow 215

40
8
I would think because unlimited co2 outside which helps a plant in high heat. If you have co2 indoors and the temp is high you wont have a issue but the co2 has to be the same as the ppms your feeding your plants.
 
B

bastard_x

86
0
Survival rate of the outdoor plants is much less in extreme climates. I watched someone kill 9 0ut 0f 12 plants trying to grow them in the desert and the three that survived were very stressed and weak . Harness the power of both indoor and outdoor with greenhouse in extreme heat use a swamp cooler to keep temps down .
 
Misterdirt

Misterdirt

156
18
I think outdoor plants face a lot more stresses while they're growing, and can recover from temporary stresses faster. I think it's mostly the root system and the ability of the plant to regulate its temperature due to that large system.

Indoor plants usually don't face a lot of stress, and when they do, it's an isolated event. They had no need to put resources into developing a robust root system and move water through the plant faster.

During my first indoor grow, I thought I'd give one of my plants a "treat" and put it outside during a beautiful, sunny day, when it was about 78 F outside. Two hours later, the plant was on life support, and the conditions weren't even harsh in the least. It just couldn't increase transpiration fast enough to deal with the water loss from the more intense sun and the wind.
 
T

theherbalizor

Premium Member
Supporter
1,412
48
I have very sucessfully grown inside in 40 deg c conditions plus. Key is air exchange. We only had 4 x 600 in a 2m x 2m area but had over 3000 cmh air exchange. Massive yields of solid stinking buds.

I am sure it the airflow was less then there would have been loads of problem.
 
fatawa

fatawa

1,664
263
A buddy of mine asked me why cooling was such a big deal in the grow room, his point was that outdoor plants do fine in the summer heat. I had no idea how to answer that, never thought about it.
you cool for multiple reasons indoor.one is optimal temps r not what they r outside.wile u can get away with high temps indoors if u hav wind whipping via fans it will not grow as quickly tho.another is bugs.mites n mosts pests thrive n high heat/stagnant air/high humidity.an ac fixes each
 
fatawa

fatawa

1,664
263
I would think because unlimited co2 outside which helps a plant in high heat. If you have co2 indoors and the temp is high you wont have a issue but the co2 has to be the same as the ppms your feeding your plants.
common myth....co2 doesnt mean run more heat.and i hit 1200ppm on co2 so feeding yur plants the same is not smart
 
fatawa

fatawa

1,664
263
20170708 082627
Indoor plants usually don't face a lot of stress, and when they do, it's an isolated event. They had no need to put resources into developing a robust root system and move water through the plant faster.
alot of crazy claims on here lately...ill take the pepsi challenge to this statement..i ripped this plant a wk ago n got lazy n didnt throw the roots away yet.this is a 18gal tote,only a 3wk veg then flip.
 
G

GROWNewbieee

18
3
Whats a ideal temp and humidity for seedlings to harvest.
 
Top Bottom