Best temperature range for growing cannabis?

Best temperature range for growing cannabis?

  • 60f-69f

  • 70f-79f

  • 80f-89f

  • 90f-99f

  • (Other)


Results are only viewable after voting.

superbak3d

Well-Known Member
Outdoor temps this morning was 9F.

Tent before lights on was around 58F. Hasn't hurt my plants yet, just turns them purple.
 

Dr. Who

Well-Known Member
Opinions anyone?
Hey Hydro,,,,,I wasn't going to comment but, why not .....

Day time temps that have worked best for me have been .... Ambient room temps of around 75F - Lights on.
Depending on what I'm attempting to do as far as "color" expression. Lights off temps may dip to 60 but, 65 is my normal heating temp set point otherwise.

Cold temps for running like mister "REX" has above will limit bud size and density far more then he either will admit or (more likely) has experienced.

To take temps to another level is to look closely at differing temp levels and the height of there change or variations. There is a member here who carefully watch's this and runs a bloom like this (this has caught the eye of several advanced members and has lead to some interesting results from testing). At the canopy level your looking for about 90F. and at the pot level about 65F. Naturally the temps progress down as you meter lower from the canopy. The idea has made for some interesting results.....worth a try if you can!

Now when you run Co2. You must run higher temps and follow the VPD closely!
At 1500ppm controlled. You must run over 86F. I found I like 90F and 75-80% RH! Use less and you just waste money as the effectiveness of the supplemented Co2 is reduced on bell curve. When using Co2 you are actually slowing the plants responce to the "light saturation point". The plant (with out Co2 supplement) actually hits a point called the light saturation point (earlier in the day then many think). At this point the plant actually begins to change on the cellular peptide level to protect it's self from the intense light of day (high watt or high lux out put lighting does do this). At night the plant will change or revert back to this daytime cellular set and start the process over again.
What the increased Co2 does is allow the plant to delay this cellular change by around 30% +/- and that covers the corresponding increase in plant yields with Co2 use (+/-). The thing is with supplementing Co2. You MUST use high U/mol - LUX lighting on a corresponding scale to amounts of Co2ppm and light intensity increase......If interested I can give you the amounts by rise in each.

Clear answer for a clear question
 

bird mcbride

Well-Known Member
I set it so the heat comes on at 69F and cuts out at 72F. The blowers come on at 80f and cut out at 77f. In spring and fall when it's too hot for the blowers I run co2.

The mother room is set to 69-72F.
 

Connoisseurus Rex

Well-Known Member
No fucking wonder!!!!!
That explains the bad and BS answers you give!
My mother always told me not to argue with idiots. They just drag you down to their level and beat you with experience.

Now I don't think you're an idiot (quite intelligent it would seem), but close minded ignorance is right up there with idiocy.

Do you know what happens when you cold grow? Do you know how it affects your roots and foliage? Lemme guess... It stunts growth and lowers production, right? Nope. They just transpire more, a plant function that can be very useful if you know how to use it.

Don't knock it til you've tried it. I only run those low temps in the seedling and late flower stage as posted.
 

Dr. Who

Well-Known Member
My mother always told me not to argue with idiots. They just drag you down to their level and beat you with experience.

Now I don't think you're an idiot (quite intelligent it would seem), but close minded ignorance is right up there with idiocy.

Do you know what happens when you cold grow? Do you know how it affects your roots and foliage? Lemme guess... It stunts growth and lowers production, right? Nope. They just transpire more, a plant function that can be very useful if you know how to use it.

Don't knock it til you've tried it. I only run those low temps in the seedling and late flower stage as posted.
Hmm, instead of saying something to piss you off more and keeping the piss flying, I'll say this.

With all "due" respect.
I've most likely done this longer then you have been alive!
I tried your colder temp/higher transpiration method many years back and found it lacking as for others that I prefer for the results given. (Not a bad root temp though!)

Your not dumb or an idiot. Your trying to learn and getting somewhere. I would have found it helpful and time saving, not to mention money saving if I had the help some offer here then. Sadly Gore had not "invented" the internet yet. Much less the PC being invented!

Just remember that YOU did the first name calling jr. I admit I did poke at you a bit as I feel you should do more reading then advising so much.

Ok then shall we play nice now?
 

Connoisseurus Rex

Well-Known Member
Hmm, instead of saying something to piss you off more and keeping the piss flying, I'll say this.

With all "due" respect.
I've most likely done this longer then you have been alive!
I tried your colder temp/higher transpiration method many years back and found it lacking as for others that I prefer for the results given. (Not a bad root temp though!)

Your not dumb or an idiot. Your trying to learn and getting somewhere. I would have found it helpful and time saving, not to mention money saving if I had the help some offer here then. Sadly Gore had not "invented" the internet yet. Much less the PC being invented!

Just remember that YOU did the first name calling jr. I admit I did poke at you a bit as I feel you should do more reading then advising so much.

Ok then shall we play nice now?
Just to be clear, I didn't call you an idiot. I said the opposite.

Anyhow, I'm game for playing nice. However, we have different grow styles and that is the apparent cause for butting heads.

That being said, I don't think you're wrong and didn't claim that you were. I simply said I can get very nice results with colder temps. I feel the results are as good as anybody growing in tropical temps can produce as well. Check the lighting thread. You'll see what I mean.

Now, maybe you've tried cold growing and it didn't work out so you said F that. Totally understandable. I'm just saying that the way I do it may be different, therefore producing different results.

If you'd like, you can try a quick experiment with some shit seeds. Try the temps I'm recommending with the humidity. Maybe it's a tad different than what you tried. After 2 weeks from pop, you'll have your results and then you can tell me it doesn't work well.
 

Dr. Who

Well-Known Member
Just to be clear, I didn't call you an idiot. I said the opposite.

Anyhow, I'm game for playing nice. However, we have different grow styles and that is the apparent cause for butting heads.

That being said, I don't think you're wrong and didn't claim that you were. I simply said I can get very nice results with colder temps. I feel the results are as good as anybody growing in tropical temps can produce as well. Check the lighting thread. You'll see what I mean.

Now, maybe you've tried cold growing and it didn't work out so you said F that. Totally understandable. I'm just saying that the way I do it may be different, therefore producing different results.

If you'd like, you can try a quick experiment with some shit seeds. Try the temps I'm recommending with the humidity. Maybe it's a tad different than what you tried. After 2 weeks from pop, you'll have your results and then you can tell me it doesn't work well.
I read ya.

As fer the temps and seedling trials - No thanks been there done that.....But I have to ask this in several questions!

Straight run or S1 seeds?
If straight run - What is your male ratio?

"Shit" seeds? I don't keep any.
 

Connoisseurus Rex

Well-Known Member
I always keep hermie seeds (shit seeds) as testers for new soil mixes and tent setup tests. Just something I do. I never let them get too far into flowering, if I let them get there at all.

I run both as I dabble in breeding. My male to female ratio doesn't stay constant but it's never been over a 60% male production.

Running those test hermies in the lighting schedule thread at those temps. You can watch them as they grow. It's just a different style of growing is all.
 

Connoisseurus Rex

Well-Known Member
oh shit
60% male? i would cry

ive been hittin ~90% female for a couple years
i know it seems crazy, true though
~15 out of 16 almost every time
I don't mind at all. I've pulled some better males than females, as far as breeding goes.

I only keep genetics from a few plants. Ones that do fine get flowered out and chopped. Ones that produce in the areas I want... They get cloned and bred.

Hoping for a nice afghani male in this next grow. Heard they're a super solid indica. I'm more sativa oriented but I've got a few crosses I would like to try.
 

TWS

Well-Known Member
I always keep hermie seeds (shit seeds) as testers for new soil mixes and tent setup tests. Just something I do. I never let them get too far into flowering, if I let them get there at all.

I run both as I dabble in breeding. My male to female ratio doesn't stay constant but it's never been over a 60% male production.

Running those test hermies in the lighting schedule thread at those temps. You can watch them as they grow. It's just a different style of growing is all.
Oh you mean pollen chucking.
 

Dr. Who

Well-Known Member
I always keep hermie seeds (shit seeds) as testers for new soil mixes and tent setup tests. Just something I do. I never let them get too far into flowering, if I let them get there at all.

I run both as I dabble in breeding. My male to female ratio doesn't stay constant but it's never been over a 60% male production.

Running those test hermies in the lighting schedule thread at those temps. You can watch them as they grow. It's just a different style of growing is all.
I would say your Male ratio is due to the cold seedling temps Rex!
If you up that to 85 - 90 F and drop as you up pot on a sliding scale. You can reach 90+% female ratio!
Seeds are only around 50% predetermined sexually (female) and the rest will react to environmental conditions!
The resulting males tend to be hardy and vigorous in my experience. Nice thing to know for your breeding projects.
 

GrowerGoneWild

Well-Known Member
I think the OP was a trick question.

Since there are so many variables with growing, you'll need to have a grow journal so you can make observations on what works and what doesn't work.
We can suggest a range of temps to work with, but the grower with trial and error will have to find an optimum range, you will have to look at your data and figgure out what works for that particular strain.

I had a problem with foxtailing with C99 in higher temps when running CO2, but chemdog didn't mind.
 

GrowerGoneWild

Well-Known Member
So, lets look at this like a math problem.. Not my strong point, if you know statistics, I could use some pointers.

I took the values for growing temp for lights on, no co2 and found the middle range for example 77-80, I split the difference.. 78.5 for example.

Here's the values I got from the thread. Based off of community answers.

78.5, 76.5, 75, 85, 75, 84.5, 77, 67, 73.5, 77, 78.5, 74.3

So I applied the standard deviation formula, https://www.easycalculation.com/formulas/standard-deviation.html

76.81 F Is ideal, +/- 4.5 F to stay within the optimum range.

(+/- 10F in my opinion, round up or down +/- 1F from 76.8 should be ok... again more opinion.)

So lets look at the chart, for VPD, so at that temp we could run about 60%RH.

I didn't add my answer because I didn't want it to be biased, but I like the higher 70's mainly as a cushion in case of malfunction. But I dont use that much precision myself I dont have datalogging.
 
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