Importance of humidity during flowering?

How much would it affect the end result if humidity were a bit low throughout the flowering period? Say 20-30% average humidity.

shouldn't hurt too much, might slow down growth a little, 40% is optimal.

Humidity is supposed to be low during flowering. Big, dense buds + high humidity = bud rot. But there is also powdery mildew and other potential fungal infections that like it where it is warm and humid.

Cannabis grown in dry, arid climates tends to produce more trichomes as a defense mechanism supposedly.

I also read that low humidity triggers the plant to react so it doesn't dry out, hence more resin.

don't listen to Nullis, what he just said is stupid. cannabis always need moisture to a certain degree, not enough humidity and the pants' leaves will dry and krinkle. cannabis is neither a cactus nor a thistle!

tet1953 said:

I also read that low humidity triggers the plant to react so it doesn't dry out, hence more resin.

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The main stalk has no resin glands, so how does that keep hydrated? Without the main stalk the plant is pretty much fucked, your statement sounds like an old rumor.

Well, maybe you're right but stalks aren't very hydrated to begin with in my experience. They are more of a conduit. I was referring to buds and leaves, so they don't dry out. The theory made sense to me.

I get the theory, to keep the moisture from evaporating, it covers itself in water repellent oil (resin glands), but then shouldn't we be growing super potent weed in deserts and tundras? I don't like to stress out my plants, I water and mist them as much as they need, and I grow ass kicking buds.

Well, I'm not advocating for 25% RH. I am offering a theory why 40% is better than 60%, is all.

I'm too stoned and drunk to argue anymore, as long as the plant is happy and healthy then I have no room to critique.

Pureblood89 said:

don't listen to Nullis, what he just said is stupid. cannabis always need moisture to a certain degree, not enough humidity and the pants' leaves will dry and krinkle. cannabis is neither a cactus nor a thistle!

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Hmm... I don't get why the leaves on my plants are so lush... and green... and hydrated, then. Possibly because my cannabis plants are getting the great majority of their water by absorbing it through their fucking roots, which are growing in moist fucking soil.

Some people don't spray/foliar their plants at all and grow in even drier climates (great weed does grow in the desert, come on!). All I am saying is that there is no need to increase your humidity during flowering if it doesn't even go lower than 30%. The bigger your buds are, the denser your buds are, the higher your humidity: the greater potential for mold. Simple fact.

Pureblood89 said:

I get the theory, to keep the moisture from evaporating, it covers itself in water repellent oil (resin glands), but then shouldn't we be growing super potent weed in deserts and tundras? I don't like to stress out my plants, I water and mist them as much as they need, and I grow ass kicking buds.

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Once again, potent cannabis just happens to grow in arid climates (and most other climates). That is how the inference between hot/arid climates and resin was drawn in the first place. Even so, just because there is a lot of a resin on a plant doesn't mean it is full of THC.

pureblood u dont know shit , nullis is right.when your flowering the lower the humidity the better. anywhere from 20%-60% is ok but u dont want it going over 70% RH

I try to keep between 35-45% rh during flower. Just what I do, not necessarily the best.

Low humidity can be a good thing. Many strains grown in high altitude, low humidity climates develope heavier trichome production.

I actually live in a high elevation desert climate... the issue isn't humidity, it's heat. I grow from seed to harvest in 0%-10% humidity with no ill effect. Transpiration and vapor pressure deficit is definitely elevated but as long as the root zone remains well watered, there's absolutely no ill effects.


Here are a few samples of my buds grown in 0% percent humidity:












I'm beginning to feel like it's a blessing to live in such an arid climate. Low humidity does amazing things to cannabis flowers.

smoove said:

Low humidity can be a good thing. Many strains grown in high altitude, low humidity climates develope heavier trichome production.

I actually live in a high elevation desert climate... the issue isn't humidity, it's heat. I grow from seed to harvest in 0%-10% humidity with no ill effect. Transpiration and vapor pressure deficit is definitely elevated but as long as the root zone remains well watered, there's absolutely no ill effects.


Here are a few samples of my buds grown in 0% percent humidity:


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View attachment 1388353


View attachment 1388354



I'm beginning to feel like it's a blessing to live in such an arid climate. Low humidity does amazing things to cannabis flowers.

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Is it snowing?? Damn those buds look delicious!! +rep for them pics!

Your an idiot! Do some homework. Resin glands are the plants nature defence mechanism to keep the plant safe from burning! Trichomes in fact have the highest uv protection of all products found in plants!