[Bloom SA]

Originally Posted by Spaventa

Aspirin. 1 dissolved /litre. Apart from being salicylic acid that is good for all sorts of other things in plants, its an antitranspirent. It works on the stomata opening.

Gotta love ICMag, you folks are very helpful. Curious AF on the aspirin. When does one apply it and how often? Won't stomata being closed be more harmful than good once the sun rises again?

[Spaventa]

Originally Posted by Bloom SA

Gotta love ICMag, you folks are very helpful. Curious AF on the aspirin. When does one apply it and how often? Won't stomata being closed be more harmful than good once the sun rises again?

Antitranpirants are widely to increase crop yields, quality, resistance to pests, disease etc etc They use them on fruit and veg to increase tumescence/swell - nothing harmful, they will just transpire less and compensate by drinking less - that the other thing you should see - all that water that ends up in your dehumidifier.. more of it will stay in your res.
Water it in dissolved at 1 pill per litre and repeat as needed, maybe each week but let your plants and RH/water consumption guide you.

[farmerlion]

Bloom SA. one simple this that costs you nothing. Is to water in the evening. Your moisture will soak and spread more thoroughly. Your plants will take what they need. I have also used multiple heavy wire plant markers. I pull them out before watering so the water drains down better, them replace markers. I use the markers as a cheat sheet for specific plant nutritional requirements. Personally I'm not a big fan of defoliating a plant until a few days before harvest. But I do remove dead and dying leaves thoroughly, daily. Defoliating isn't wrong by any means. If you over do it you screw yourself hard. Peace

[Bloom SA]

Originally Posted by farmerlion

Bloom SA. one simple this that costs you nothing. Is to water in the evening. Your moisture will soak and spread more thoroughly. Your plants will take what they need. I have also used multiple heavy wire plant markers. I pull them out before watering so the water drains down better, them replace markers. I use the markers as a cheat sheet for specific plant nutritional requirements. Personally I'm not a big fan of defoliating a plant until a few days before harvest. But I do remove dead and dying leaves thoroughly, daily. Defoliating isn't wrong by any means. If you over do it you screw yourself hard. Peace

very interesting point of view this. Everything ive read so far says to only water early on in the day due to RH issues at night

[redlaser]

What are your outside temps at night? I’ve been dealing with the same issues, last fall I just either let the exhaust run all night or exhaust for 10-15minutes per hour on a timer. I’ve talked with others that only vent 2-3 times nightly, some call it burping the baby.

I was running into December of last year, air temps hitting 30-33F (0 celcius). Soil temps still in mid 60’sF. I have propane heat, but quit using it because of the humidity. Everything was actually going pretty well before winter rains came. Up until November I could keep humidity at night at 60-65%, and temps 73-78 degrees, which is where I want it to be. Once the first inch of rain fell after no rain for six months my undersized dehumidifier was overwhelmed.

I plan on adding a wood stove of some sort, debating pellet versus regular heat since firewood is abundant. Should help with humidity as well. I’ve seen electric heated houses but unless you get cheap electricity, kind of expensive.

[farmerlion]

I'm very far north, RH hasn't been an issue for me. All locations present their own problems. Best of luck. Peace

[2011rex87]

Keep in mind if you are supplementing CO2 into the grow space you are not going to want to exhaust that out before your plants have a chance to benefit. That can complicate your humidity/environmental issues. Are you supplementing CO2 at all? Sounds like you are not but it's good to ask...

[hamstring]

Hoping to build my own greenhouse next year. Like the original poster I have concerns about high humidity too. I live in the midwest and come October the rains start. It would seem even with fans you are bringing in humid air?

I was looking online at greenhouse heating to control humidity. I have zero experience but wanted to ask others about the some of what I found.

First most of the articles you find center around heating rather than to control humidity.

Wood Stoves- Easy to use and maintain but only have a 4hr burn time before they need to be reloaded.

Pellet Stoves-Don't need to be refueled but heard the augers can rust easily and stop working. Especially in the summer when not being used and higher humidity conditions.

One thing many recommended was drip irrigation over hand or spray to cut down on excessive moisture.

Which begs another question for MJ cultivation are containers better than raised beds in a green house to control humidity during flowering? Was hoping to go with raised beds and go completely organic, earth worm, living soil etc but sounds like could have a lot excess moisture in the ground to maintain this soil culture.

Sounds like a damed if you do damed if dont situation.

[Bloom SA]

Originally Posted by 2011rex87

Keep in mind if you are supplementing CO2 into the grow space you are not going to want to exhaust that out before your plants have a chance to benefit. That can complicate your humidity/environmental issues. Are you supplementing CO2 at all? Sounds like you are not but it's good to ask...

No CO2 supplimentation. I've made a supersoil with horse shit, bonemeal, chicken shit, molasses, dolomite lime, river sand and a huge army of red worms. I was hoping the soil alone with the decaying Organic matter, red worms and mycorizal fungi would bump up co2 levels but i havent tested the air. I don't run any ventilation at night, only the dehumidifier and oscillating fan so theoritically at first light there should be plenty of co2 from what the plants let out into the greenhouse at night

[2011rex87]

Originally Posted by hamstring

Which begs another question for MJ cultivation are containers better than raised beds in a green house to control humidity during flowering?

I would think you want to minimize the surface area for the moisture to evaporate off into the air so maybe pots would be better for you than a raised bed but you will lose the benefit of all the extra cu/ft of soil.

Flowering in high humidity is not necessarily a death sentence. I want to put that out there incase you end up having to try it. It does increase the risk of mold but it's not a promise that you will get moldy buds just because. You can take other measures to try to mitigate mold like avoiding the use of wood in the grow space and filtering all your incoming air, cleaning your grow space, etc. I have seen great plants grown in high humidity, it's just not always ideal. So don't panic and just keep on and maybe you'll have a great success in the end regardless.