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How susceptible to frost is cannabis?

Treevly

Active member
Is cannabis one of the first crops to suffer, or the last, or... in between? Does it ever get wiped right out, at the freezing point air temperatures?
Thanks for any wisdom.
 
T

Teddybrae

Oh ... Lake Erie. Well, I think St. Phatty posted about one of his that got covered by snow and survived.
I 've seen them turn purple from frost.
And ya gotta think: They grow very well in the Himalayas (eg: Hindu Kush.)
Lack of sunlight probably hinders their growth more.
 

Bud Green

I dig dirt
Veteran
My buddy was growing in the Catskill mountains in the mid 70's...

His plants got an inch or two of snow on 'em a couple of years and he told me he was worried, but then he said it made the plants even better...

if you're talking frosts around 20 F., you better cover them or get them in...

..
 

Treevly

Active member
Oh ... Lake Erie. Well, I think St. Phatty posted about one of his that got covered by snow and survived.
I 've seen them turn purple from frost.
And ya gotta think: They grow very well in the Himalayas (eg: Hindu Kush.)
Lack of sunlight probably hinders their growth more.

Good points, thank you.
 

Treevly

Active member
My buddy was growing in the Catskill mountains in the mid 70's...

His plants got an inch or two of snow on 'em a couple of years and he told me he was worried, but then he said it made the plants even better...

if you're talking frosts around 20 F., you better cover them or get them in...

..

Actually, the forecast is 32° for an hour or so at 05:00.
 

aridbud

automeister
ICMag Donor
Veteran
We've had seeds over winter and sprout in Spring in sidewalk cracks. Light frost doesn't hurt plants. Even snow doesn't in moderation. Depends on strain, I'm sure.
 
T

TakenByTheSky

I follow this guy on IG that travels around india, he has shown many pictures of the years of Indian landraces with icicles literally hanging off the leaves and buds and the plants are still alive.

Our modern hybrids have been so acclimated to the perfect indoor environment frost will kill most of them outdoors.
 

star crash

We Will Get By ... We Will Survive
ICMag Donor
Veteran
We had a hard frost Last night I discovered frosted flowers...They defrosted and looked OK more purple even...It’s going to happen again tonight for one hour at dawn it’s going to dip below freezing
 

Cantharellus

Active member
Most can handle frost the problem to watch for is the bud rot this time of year. If they don't get good sun still they never dry out good during the day and the rot will set in.
 

VerdantGreen

Genetics Facilitator
Boutique Breeder
Mentor
ICMag Donor
Veteran
Many plants can handle a certain amount of frost. Snow cover often actually insulates plants against lower temeratures.


What can damage frosted plants quite badly is if they get thawed out quickly in the morning sun - this is what ruptures the cells and destroys them more than the frost itself - so gardeners will usually site susceptable plants and things like greenhouses so that they don't get blasted by early morning sun and are shaded at that time so that the frozen plants thaw out more slowly with less damage.
The purple colour seen at these times is from the plants making anthocyanin - their natural anti-freeze .


VG
 

troutman

Seed Whore
If you have plants in the backyard and you think a light frost will occur. Get out and mist the plants
and the surrounding soil will cause the frost crystals will melt. Even cold water is warmer than ice.
Having a plant misting system would be the best thing. Don't use hot water though. :tiphat:

https://frostprotection.weebly.com/the-science-behind-it.html

Freeze Protection Methods For Crops

Last year, I was at one of my guerilla patches misting the plants by hand.
It was nice seeing ice crystals melt in the early morning Sunlight from the
misting I was doing. :)
 

therevverend

Well-known member
Veteran
Older plants do better then young plants. That said a couple years back a friend had some black tar paper on the ground near rotten seeded buds from the year before. They sprouted in late February with snow on the ground. Of course there was intense sunshine and the tarpaper absorbed the heat, radiated it at night. There's lots of tricks like that you can use, troutman's water trick is a good one.

Plants do okay with light frosts, once the temperature gets below 30 degrees F they don't last long. The duration is important, a couple hours at night is no big deal, a hard frost at 26 for half a day is fatal. Last year I left a Kashmiri landrace plant on my deck late until the end of November. I finally decided to harvest her after she turned into a budcicle. I could tell the frost was starting to destroy the plant tissue, you can see by how the leaves are drooping.

picture.php
 

hamstring

Well-known member
Veteran
Forst vs freeze warnings

Plants can withstand some light frost but if your local weather calls for a freeze warning. Your plants are toast. They will not make it through a freeze.

Frost=36 deg or above
Freeze = 32 deg or lower
 

Dankwolf

Active member
Some strians take extended freezes with out issue . others pretty much stop growing after a freeze .

I have 1 strain that can freeze solid day after day with out issue .
 

Im'One

Active member
Very good info. I have two romulan grapefruit plants that are late bloomer phinoes and I thought were male! They finally produced flower and I out them back in the screen porch. I'm going to put them in the green house. I think they have six weeks to go and we have frosts around the middle to end of October. Maybe I will be ok. They are too tall and lanky to go in my grow closetr. Besides it's full of Tashkent indicas!
 

TychoMonolyth

Boreal Curing
If you have plants in the backyard and you think a light frost will occur. Get out and mist the plants
and the surrounding soil will cause the frost crystals will melt. Even cold water is warmer than ice.
Having a plant misting system would be the best thing. Don't use hot water though. :tiphat:

https://frostprotection.weebly.com/the-science-behind-it.html

Freeze Protection Methods For Crops

Last year, I was at one of my guerilla patches misting the plants by hand.
It was nice seeing ice crystals melt in the early morning Sunlight from the
misting I was doing. :)
Great solution.
 

TychoMonolyth

Boreal Curing
Some strians take extended freezes with out issue . others pretty much stop growing after a freeze .

I have 1 strain that can freeze solid day after day with out issue .

Same here. Last year my Swazi took 4 or 5 hard frosts and two freezing nights. The last one had snow. I harvested the next weekend after the last freeze in November. The fan leaves took a beating, but the buds sparkled like diamonds.

My Freakshow are all but dead with a few cold nights without frost. Zero seed maturity :( This is definitely an indoor strain up here.
 

blondie

Well-known member
My temps were forecast to be 35 so I didn’t worry. Turns out it dipped down to 28. I can’t look until tonight or tomorrow. Two were about done and I was pulling this week. If it happens again I’ll throw a blanket over them.
 

radioman

Active member
Let's see - 29F on Saturday morning, 30F on Sunday morning and 29F this morning (Monday). I checked on some yesterday - not for frost damage but thief damage (none from either). I got my plants in the Forest but my neighbor (a young guy) had his in the backyard. He has been covering the last couple nights but now I notice that he picked them this morning. He had some nice plants but they weren't done yet. I would have left them. Often times (I think anyway) - People will justify picking their plants early - Better get them before the frost, Better get them before somebody else gets them, Better get them before the Law, etc - I have done it myself...
 

radioman

Active member
Also want to say - The temperature only dipped below 32F for an hour or two - it wasn't in the 20's all night...
 
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