What does cold stress look like?

Guerilla Kush

Guerilla Kush

Active Member
Hi people, my question is: What symptoms does low temperature cause in a flowering cannabis plant?

A few hours ago I had a plant flowering in a box on a balcony - it was in its 7-th week of flowering and the nugs were on the fluffy side but still cool.
Apparently, it's winter time and needless to say the temperatures on the balcony are very low. At the same time when the 12/12 lamps are on, the temperature inside of the box gets more on the hot side. So I have bad ventilation and big temperature differences going on.

The cold weather hit us two weeks ago but the plant was doing OK for awhile.
However, at one point it started to look bad - the leaves started to dry off and turn brown and crispy and today I noticed that some of the buds were looking very limp and were coming off from the stem very easily.
They resembled frozen broccoli that has been heated back to room temperature - limp, wet and soft.
I was scared that this may be bud rot and harvested the plant, making sure to dispose of whatever limp nugs I was able to locate.

Now, what are the chances that this limping and water soaking of the buds could be caused by the cold temperatures and not by bud rot?
And again: what symptoms does low temperature cause in a flowering cannabis plant?
 
StewartWarner

StewartWarner

Active Member
I cant tell you exactly, hopefully someone will come along who can. but if i had to guess i would say the wild temp changes are not doing your baby any good do u have any way to regulate temps at night (wal-mart heater? 20$)
 
sensisensai

sensisensai

Well-Known Member
Extreme temp changes can wreak havoc on ur plant. Powdery mildew is the most common result of hot days cold nights and low light levels. Can u post any pics of what's going on? What kinda lights. Nutes. soil. What's ur Ph? Happy to answer just need some more info and a pic if possible
 
Guerilla Kush

Guerilla Kush

Active Member
Isn't powdery mildew supposed to leave white-ish spots all over the plant? Because the plant did not show any white spots, just drying off of the leaves and then softening of the buds. Like I said, the buds looked like frozen broccoli that has been brought back to room temperature - totally soft and limp.
I have seen frost do that to other types of plants too, but you never know if it's the frost or some nasty stuff.
I will try to post the most recent photo that I have.
 
M

mjjbabel

Well-Known Member
My experince is as follows,

Had plants outside in a large grow box. Inside temps with lights on would get 72-78, inside temps with lights off would get down as low as 35.

The plants that were near where the fresh cold air was coming in had a noticeable purple color to them. I have been growing the same phenotype (cheezel) and never noticed any purple before the cold hit.

It sounds like your plants actually froze. What you described is just how my outdoor garden looks once we get a couple freezes.
 
Guerilla Kush

Guerilla Kush

Active Member
Hmm, that's actually good news. I prefer the frozen plant theory over the bud rot theory.

Now, at one point I did overnute the plant and fed it a 3X dose of nutes, but it was doing fine for a month and I'm wondering if overnuting shows its symptoms a month later (if we accept that overnuting causes the buds to go limp and soft, of course).
Also, ever since I realized that I'm overnuting the plant (3+ weeks ago), I have been watering it with pure water only. So I think the limp bud problem was not caused by overnuting.
 
sensisensai

sensisensai

Well-Known Member
Right. I wasn't implying u had it. Its just an environment it would thrive in si keep an eye out.
I have to agree it sounds like your plant physically froze. The ice buildup likely damaged a lot of cells and tissue. Idk that they'll recover or not.. most wouldn't however everytime I count cannabis out it comes back to spite me lol. As for purpling. That is the first sign ur rooms getting too cold. Obviously some phenotypes turn purple but most plants will turn purple in temps below 60. The cold chokes out the chlorophyll that makes them green (this is a very ignorant non scientific explanation of course lol. There are many threads describing the process so I wont bother)
 
Guerilla Kush

Guerilla Kush

Active Member
I expected the plant to turn purple too, but it never did. I guess some strains don't get purple, no matter what.

As for freezing completely, I'm not 100% sure that it froze. The grow box is covered with a thick floor carpet and I assume this keeps the warm air in and keeps the inside temperature from dropping below the freezing point. The balcony is not open too - it's enclosed in glass. Still, the temperature does drop really low out there. Sometimes there's frost on the balcony glass - a sign that the glass itself is below freezing temp.
But maybe it's not neccessary for the plant to freeze completely? Maybe temperatures close to the freezing point can damage its cells too? I don't know... I'm just hoping it was not a bud rot problem.

Photos are coming soon.
 
sensisensai

sensisensai

Well-Known Member
The pics will.definetly help. Bud rot is usually pretty evident based on smell most times but if not u know the second you open up a nug. :puke: hopefully u Dodge the rot bullet.
 
Guerilla Kush

Guerilla Kush

Active Member
^ I noticed that, with the appearance of the first signs of problems, the plant stopped to smell-up the whole house.
It used to stink-up all rooms with its garlic-like smell. And then all of a sudden it wasn't smelly anymore.
Of course, the buds still have a smell but it is not as strong as it used to be when the plant was healthy, and it is now a different, kind of a harsh smell.

What does bud rot smell like?
 
Guerilla Kush

Guerilla Kush

Active Member
I inspected the buds under a microscope, was looking for bud rot spores. Couldn't see anything suspicious - no spores, no web-like matter. The buds look clean.
When the problem hit, the buds were not well formed, I can't even say that there were any buds whatsoever - as you can see they were leafy and airy, which is what bud rot is supposed to hate.
There was no browning of the bases of the buds or the leaves either.

On the other hand the symptoms were matching bud rot - leaves that come off easily from the stem when you pull on them, change of smell, some wet and soft buds...
Check out the images below. They show some of the problems right before I harvested the buds - crispy brown leaves, etc.

I don't know if all these problems were caused by the cold off-light temperature, the hot on-light temperature, the overnuting or anything else... I just hope it was not bud rot.
Check out the photos below and tell me if this looks like bud rot to you.

1.jpg 2.jpg 3.jpg
 
Bakatare666

Bakatare666

Well-Known Member
Guerilla Kush said:
Hi people, my question is: What symptoms does low temperature cause in a flowering cannabis plant?

A few hours ago I had a plant flowering in a box on a balcony - it was in its 7-th week of flowering and the nugs were on the fluffy side but still cool.
Apparently, it's winter time and needless to say the temperatures on the balcony are very low. At the same time when the 12/12 lamps are on, the temperature inside of the box gets more on the hot side. So I have bad ventilation and big temperature differences going on.

The cold weather hit us two weeks ago but the plant was doing OK for awhile.
However, at one point it started to look bad - the leaves started to dry off and turn brown and crispy and today I noticed that some of the buds were looking very limp and were coming off from the stem very easily.
They resembled frozen broccoli that has been heated back to room temperature - limp, wet and soft.
I was scared that this may be bud rot and harvested the plant, making sure to dispose of whatever limp nugs I was able to locate.

Now, what are the chances that this limping and water soaking of the buds could be caused by the cold temperatures and not by bud rot?
And again: what symptoms does low temperature cause in a flowering cannabis plant?
Click to expand...
My last ones ran longer than I wanted, and the cold came, a couple cold nights they seemed to like, but when I had a week of 38-40 degree nights solid, the Sativa dominant didn't get hit so hard, but the Indica dominant plant really got a bad P lockout, and almost everything turned purple.
Both plants seemed to take over a week to recover, and start growing again.
*They were both close to finishing when this happened.
 
Guerilla Kush

Guerilla Kush

Active Member
Guerilla Kush said:
I inspected the buds under a microscope, was looking for bud rot spores. Couldn't see anything suspicious - no spores, no web-like matter. The buds look clean.
When the problem hit, the buds were not well formed, I can't even say that there were any buds whatsoever - as you can see they were leafy and airy, which is what bud rot is supposed to hate.
There was no browning of the bases of the buds or the leaves either.

On the other hand the symptoms were matching bud rot - leaves that come off easily from the stem when you pull on them, change of smell, some wet and soft buds...
Check out the images below. They show some of the problems right before I harvested the buds - crispy brown leaves, etc.

I don't know if all these problems were caused by the cold off-light temperature, the hot on-light temperature, the overnuting or anything else... I just hope it was not bud rot.
Check out the photos below and tell me if this looks like bud rot to you.

View attachment 2451635 View attachment 2451636 View attachment 2451637
Click to expand...

What about these pics? Do they look like bud rot?
 
Guerilla Kush

Guerilla Kush

Active Member
Young Contemporary Peter said:
Can hardly see the buds in those pictures bud, can't tell if they're rotten if you can't see em. Got any others?
Click to expand...
Hi, you can't see the buds because there are no any (real) buds. The bud sites never developed large calyxes like the ones you see in High Times magazine or anything. What you see on the pics are leafy, airy flowers that were flowered under only around 100 Watts of CFL, and that started to get browning on the tips of the leaves and started to smell weird.
In this thread I am trying to figure out if the problems were caused by bud rot or by the low temperatures, etc..
 
Krondizzel

Krondizzel

New Member
In my experience, if the temp drops anymore than 20F at night (78F day temp) so at 58F and below at night, will really seem to piss plants off. 15F drop at night seems to be about optimum for me.
 
Guerilla Kush

Guerilla Kush

Active Member
Krondizzel said:
In my experience, if the temp drops anymore than 20F at night (78F day temp) so at 58F and below at night, will really seem to piss plants off. 15F drop at night seems to be about optimum for me.
Click to expand...
My night temperatures were way below 58F, I would say around 40F and maybe below that, while the lights-on temperatures were around 80F.
What will this do to the plants in terms of visible symptoms? In my case there was no any purpling of the plant matter whatsoever.
 
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