Best Strains VS High Temps

[Frijol]

Hello,
I got an indoor which gets very hot in summer 30-34°Celsius (86-94°Farenheit), its a 250 hps, but the summer is hot in here.

So im looking for strong strains against high temps.

Feminized Seeds, Indica, Sativas and Hybrids.

Thank you!

 

[Dropped Cat]

I do high temps grow too, and really the best addition
you can do for your plants is additional humidity.

Appropriate airflow, distance from light source.

No magic bullet with genetics, only wishful thinking.

 

[pop_rocks]

I do high temps grow too, and really the best addition
you can do for your plants is additional humidity.

Appropriate airflow, distance from light source.

No magic bullet with genetics, only wishful thinking.

i would think it would be co2
can you elaborate more on this?

 

[Dropped Cat]

If sealed, then co2, natch.

I am still learning about high temp grows, I have stumbled
upon threads here that discuss vapor pressure and transpiration.

My easy takeaway was higher humidity with higher temps.

 

[willyweed]

a cheap solution would be to use some 2 litre bottles of frozen water and a fan defo helps some. good luck ww

 

[stoney917]

Or a swamp cooler anything.... It's a 250 so It's a small hobby grow..... My best advice is hope u not down south .... Leave it open or skip a run..... Heat issues coming off a 250 .... Turn your house ac up ....

 

[packerfan79]

My buddy grew forum cut, tangie,monster cookies, and a couple in house og gsc crosses, and his temps got as high as 94 blew me away. It is bomb buds. I will never get that lucky. I was about to lose it when my last run was hitting 86

 

[BubbaBear]

Get strains that originated from warmer regions of the world. Sativas usually do better than indicas.

 

[Arf]

34C is not very hot, sure it's above the 25C-30C optimal range, but you have to remember that most Cannabis landraces are from hot places around the globe that often go way above 34C.

If you keep the humidity up, the specific heat of the air will increase, thus stabilizing the temperature a bit, of course air circulation will help cool by evaporation.

Using 150W of decent LEDs instead of the 250HPS will knock a lot of the heat.

 

[packerfan79]

I have to disagree on the sativa comment. Sativas tend to turn to larf when the temps are high. You could use a swamp cooler. That will increase the humidity and cool things down

 

[Tynehead Tom]

I just grew 4 different varieties with varying phenotypes , average flower temps this run 84F to 92F in a 6x6x7 grow tent with a 940HPS , passive intake, 450cfm exhaust.
outside night time air for cooling only.
Killed it again and everything handled it awesome. From straight up indica to full on sativa.
95F+ is hot , below that, I dunno what to say. Plants should handle it just fine if you are water correctly and humidity is over 50%

 

[tree dawg]

I live in deep south swamp cooler a must with dehumifer

 

[cultivatorkid]

I live in deep south swamp cooler a must with dehumifer

i dont see any with good reviews

 

[MOONWATER]

I've found myself in the same boat looking for heat resistant strains- temps here in the high desert of California get over 115 Fahrenheit easy and will destroy non heat resistant plants in the blink of an eye. Wish 92 was all I had to worry about Arid climate landraces.. And the bigger your plants the easier it is for them to regulate their core temp and keep them cool so maybe something like starting your veg in a smaller, more easily cooled room? Wait till they grow a little more before moving them into the heat- My 2 cents good luck on your search!

 

[corky1968]

I much prefer Fall and Winter growing as there's no heat issues ever where I'm at anyways.

 

[pinkus]

While making them happy with air movement and humidity will help, appropriate genetics can help as well IME and O. Satori from Mandala did in fact do better than my other outdoor plants here in TX.

 

[ChaosCatalunya]

Fat Indica buds seem to rot in high heat worse than fluffier hybrids, the chart above shows why you need 80% RH when temp is over 30C. Remember that your carbon filter will not work properly, use Ozone downstream as well...

 

[GoatCheese]

World of Seeds' Afghan Kush seems to do fairly well in hot temps. Haven't grown it pure while it was super hot, but two crosses i made with Afg Kush pollen did well in over 35 temps with soil drying out more times than welcomed by the plants..
Most other strains in the tent grew few nanners because of heat stress, cause i couldn't rise the light any higher, as did both mom-plants of these crosses in hot, but these girls didn't
..and they expressed two different Afg Kush phenos too, not the same, and both did quite well..

 

[Jhhnn]

While making them happy with air movement and humidity will help, appropriate genetics can help as well IME and O. Satori from Mandala did in fact do better than my other outdoor plants here in TX.

Satori did well for me before I got temps under control. Seems to need more calcium than many others. It's an excellent, hardy & well behaved cultivar that's easy to grow.

 

[Douglas.Curtis]

View Image
the chart above shows why you need 80% RH when temp is over 30C.

That chart says I flower in 18+ VPD... I say people put too much stock in it, at least for cannabis.

The reason you want high humidity in flower, when you're unable to reduce heat, is due to transpiration limits. When humidity is high, cannabis doesn't use any transpiration for keeping hydrated. This leaves all the transpiration capacity for cooling. Cannabis prefers leaves at around 70F and will use evaporative cooling to stay there.

On a side note, trichome bearing plants (cannabis is one) produce a higher number of trichomes in low humidity environments. It's a genetic response for helping the plant stay hydrated. (Edit: this is incorrect. Plants grow less 'plant,' in lower VPD environments, under the same number of trichomes.)

Douglas