Terpenes lost due to high growing heat? - Cannabis Botany and Advanced Growing Science - International Cannagraphic Magazine Forums

de145 · 05-01-2012, 09:18 PM

I was reading a lot of stuff on LED lighting on here the other day and a lot of people kept saying that the LED grown buds tasted better and had richer smells than same pheno clones grown under HID.

I've heard the same thing said about outdoor grown weed as well.

I'm also personally experiencing a problem where every kind of weed I grow has a very similar smell and taste with a few exceptions and I also know my heat is probably too high.

It seems logical that excess heat while growing could explain a lot of that. Terpenes boil off at all different temps and it could be that some of the most delicate are being burned off in hot growing conditions.

I sat down and devoted some time and did a big search online and looked for credible sources and recorded every temp I could find that were posted as minimum, maximum and ideal for growing. They varied all over the place needless to say so I had to average.

I averaged them and came up with:

Maximum peak temp while growing to not exceed: 29C (84.2f)
Ideal normal growing temperature: 25c (77f)
Minimum temp at which growth will occur: 15.5c (60f)

I'm starting to think those are too high and I'm losing terpenes.

What say you?

Hydro-Soil · 05-02-2012, 05:14 PM

Quote:

Originally Posted by de145

I'm also personally experiencing a problem where every kind of weed I grow has a very similar smell and taste with a few exceptions and I also know my heat is probably too high.

Major reason for everything tasting the same... nutrients and how you're using them.

- Avoid overfeeding
- Flush for a week to 2 weeks, depending on your strain

As for heat? Best buds come out from under HID's (for me) when temps don't exceed 75F.... That, and the plants are backed away from the light for 7-10 days before chop.

Stay Safe!

de145 · 05-02-2012, 06:15 PM

Quote:

Originally Posted by Hydro-Soil

Major reason for everything tasting the same... nutrients and how you're using them.

- Avoid overfeeding
- Flush for a week to 2 weeks, depending on your strain

As for heat? Best buds come out from under HID's (for me) when temps don't exceed 75F.... That, and the plants are backed away from the light for 7-10 days before chop.

Stay Safe!

So in terms of terpenes and heat t I think what you are saying is you agree that heat can kill terpenes with your comment about backing away from the lights before the chop.

RockyMountainHi · 05-02-2012, 07:22 PM

Quote:

Originally Posted by de145

I'm also personally experiencing a problem where every kind of weed I grow has a very similar smell and taste with a few exceptions

I had that problem.

Do you have little black flying bugs?

I did. --- VERY VERY BAD SIGN!!!!! That is usually heavy infestation time - they can be in the plant roots with no noticaeable flyers

Are your plants looking a little rough? Kinda like a previously unkown defficency or summtin?

Do they tend to droop after the lights have been on awile?

Mine did.

And they all had "THAT SAME BASE SMELL"

If this is sounding too real,,, you may be dealing with Root Aphids.

Leme go get you a link to a thread or two........

whatcha growing in?

I'm in rockwool cubes

Heres a thread with decen pics - not mine the other guys! lol
https://www.icmag.com/ic/showthread.php?t=237149

northstate · 05-02-2012, 07:36 PM

Quick question, how does outdoor that can see 100+ deg. F taste so good and get you very ripped? I have done in and outdoor and not sure if temps alone are responsible for terpene loss. I think having a full light spectrum does a lot for flavor, along with organic cultivation or living soil.NS

Green Supreme · 05-02-2012, 07:41 PM

If you can smell it, terps are evaporating. If they did not, smell would have likely been stronger. Peace GS

stihgnobevoli · 05-02-2012, 07:53 PM

ime heat doesn't effect much beyond how the plants grew. as for the smells and tastes being lost i find that is often the result of wrong ratios of nutes being applied. too much nitrogen can hinder trichomes and smell production as well as increase flowering times. not enough magnesium will lead to smaller calyxes it seems. etc etc. i have grown with avg temps in the mid 90's and aside from foxtails and or airy buds, the smells were still there and trichomes were there, maybe the strain but the higher temps seem to get greasier trichomes vs sticky.
plants in the wild use up their stored nutrients by harvest. i try and mimic this indoors for the best weed. after the main flush of flowers is over. somewhere in week 6-8 i stop all nutes and it's just plain water till the end. nitrogen is cut out by the end of stretch.

VerdantGreen · 05-02-2012, 07:54 PM

whilst i agree that there are many factors that go towards producing aromatic weed, i think the high radiant heat from HID lamps does contribute significantly towards terpene loss, especially of you keep the lamps as close as possible to your canopy - for most people this is simply too close - if your upper leaves are canoeing and the ends are curling upwards then thats a sure sign of light/heat stress.
unless you are measuring your canopy temp very carefully then you might not be getting the full story.
i have generally found LED weed to be more aromatic than HPS weed, and ive always put it down to either better spectrum or less radiant heat battering the canopy - quite possibly both

VG

foomar · 05-02-2012, 08:13 PM

With the same clone , soil and nutes , have noticed certain odours are much more pronounced when grown under cfl and led , than under sodium.

From what i have seen , it is influenced mainly by temperature and not the differing light spectra , strawberry is one that seems easily lost with high bud surface temps .

de145 · 05-02-2012, 11:30 PM

Hey VG, it was actually some of your posts (which I highly respect for their thoughtfulness) on LED growing I was reading that led me to the heat hypothesis.

I see people mention too much N / nutes a lot. I have ruled that out by going to extremes after experimenting with using as few nutes as possible to the point of almost deficiency showing and smelling no difference in terpenes whatsoever with the same clones.

Also I grow in soil and water by submersion of the pots in a bucket. I only need to water once or twice a week that way, they never show stress as a result but perhaps they *should* dry out a lot more to stress them into producing more terpenes?

I'm going to try minimal surface watering with a control group and see if that accounts for anything terpene related.

I'll also try molasses as indicated, I did try them when I was growing organic and to be honest never noticed any difference in smell, flavor or composition of the plants between organic with molasses in the water and my current non organic nutes.

Perhaps in the end I just haven't run into awesome pheno's from the seeds I was growing however in at least one case I know that outdoors the same cutting was much tastier and smellier using the exact same organic grow medium I used indoors for the same plant so I still don't feel like nutes are the answer to this problem.

I guess there is no clear cut consensus and most think it's nute related. I'm going to experiment with moving a control group of plants further away from the lights to a cooler spot in my cab during the flush period just to confirm for certain if there is any difference.

Also I'm going to completely revisit my harvest and cure process, perhaps I'm missing something big.

Any other ideas people have I'd appreciate as I will experiment and report back on anything that I can do that is suggested.

05-01-2012, 09:18 PM	#1
de145 Member Join Date: Jun 2010 Posts: 325	Terpenes lost due to high growing heat? I was reading a lot of stuff on LED lighting on here the other day and a lot of people kept saying that the LED grown buds tasted better and had richer smells than same pheno clones grown under HID. I've heard the same thing said about outdoor grown weed as well. I'm also personally experiencing a problem where every kind of weed I grow has a very similar smell and taste with a few exceptions and I also know my heat is probably too high. It seems logical that excess heat while growing could explain a lot of that. Terpenes boil off at all different temps and it could be that some of the most delicate are being burned off in hot growing conditions. I sat down and devoted some time and did a big search online and looked for credible sources and recorded every temp I could find that were posted as minimum, maximum and ideal for growing. They varied all over the place needless to say so I had to average. I averaged them and came up with: Maximum peak temp while growing to not exceed: 29C (84.2f) Ideal normal growing temperature: 25c (77f) Minimum temp at which growth will occur: 15.5c (60f) I'm starting to think those are too high and I'm losing terpenes. What say you?
	Quote

05-02-2012, 07:36 PM	#5
northstate IC Mag Supporter Join Date: Feb 2009 Location: There is a town called Weed? Posts: 587	Quick question, how does outdoor that can see 100+ deg. F taste so good and get you very ripped? I have done in and outdoor and not sure if temps alone are responsible for terpene loss. I think having a full light spectrum does a lot for flavor, along with organic cultivation or living soil.NS
	Quote 1 members found this post helpful.

05-02-2012, 07:41 PM	#6
Green Supreme Banned Join Date: Aug 2011 Location: heaven, B.C. Posts: 5,105	If you can smell it, terps are evaporating. If they did not, smell would have likely been stronger. Peace GS
	Quote 3 members found this post helpful.

05-02-2012, 07:53 PM	#7
stihgnobevoli Banned Join Date: Feb 2007 Posts: 5,734	ime heat doesn't effect much beyond how the plants grew. as for the smells and tastes being lost i find that is often the result of wrong ratios of nutes being applied. too much nitrogen can hinder trichomes and smell production as well as increase flowering times. not enough magnesium will lead to smaller calyxes it seems. etc etc. i have grown with avg temps in the mid 90's and aside from foxtails and or airy buds, the smells were still there and trichomes were there, maybe the strain but the higher temps seem to get greasier trichomes vs sticky. plants in the wild use up their stored nutrients by harvest. i try and mimic this indoors for the best weed. after the main flush of flowers is over. somewhere in week 6-8 i stop all nutes and it's just plain water till the end. nitrogen is cut out by the end of stretch.
	Quote 1 members found this post helpful.

05-02-2012, 08:13 PM	#9
foomar Luddite Join Date: Nov 2006 Location: UK Posts: 3,262	With the same clone , soil and nutes , have noticed certain odours are much more pronounced when grown under cfl and led , than under sodium. From what i have seen , it is influenced mainly by temperature and not the differing light spectra , strawberry is one that seems easily lost with high bud surface temps . __________________ A fine C99 cross from Head , Geisha girls Mmmmm Blackberry meets C99 in purple and gold Black Geisha Project MBS test run , and a dash of Blackberry
	Quote

05-02-2012, 11:30 PM	#10
de145 Member Join Date: Jun 2010 Posts: 325	Hey VG, it was actually some of your posts (which I highly respect for their thoughtfulness) on LED growing I was reading that led me to the heat hypothesis. I see people mention too much N / nutes a lot. I have ruled that out by going to extremes after experimenting with using as few nutes as possible to the point of almost deficiency showing and smelling no difference in terpenes whatsoever with the same clones. Also I grow in soil and water by submersion of the pots in a bucket. I only need to water once or twice a week that way, they never show stress as a result but perhaps they should dry out a lot more to stress them into producing more terpenes? I'm going to try minimal surface watering with a control group and see if that accounts for anything terpene related. I'll also try molasses as indicated, I did try them when I was growing organic and to be honest never noticed any difference in smell, flavor or composition of the plants between organic with molasses in the water and my current non organic nutes. Perhaps in the end I just haven't run into awesome pheno's from the seeds I was growing however in at least one case I know that outdoors the same cutting was much tastier and smellier using the exact same organic grow medium I used indoors for the same plant so I still don't feel like nutes are the answer to this problem. I guess there is no clear cut consensus and most think it's nute related. I'm going to experiment with moving a control group of plants further away from the lights to a cooler spot in my cab during the flush period just to confirm for certain if there is any difference. Also I'm going to completely revisit my harvest and cure process, perhaps I'm missing something big. Any other ideas people have I'd appreciate as I will experiment and report back on anything that I can do that is suggested.
	Quote