Spraying mist on my marijuana plants

A question from a fellow grower:

Is it ok to Spray or Mist the entire plants with spring water after they have now started flowering?

I would not; This could be a catalyst for mold and mildew. You need your humidity at or around 40%. Misting would significantly raise the humidity level; Without proper ventilation, you could see these issues arise.

Hope this helps.

I agree, too much moisture in the air or on the flowers and you are asking for trouble. Most growers stop or reduce foliar feeding shortly after starting the 12hr/12hr light/dark ratio for flowering. I hesitate to say this because if not done correctly you will end up with bud-rot from mold and mildew or just as bad, end up with flowers coated in fertilizer that is not good for smoking or adding to edible recipes. But you can continue foliar feeding well into flower/bloom cycle if you are careful and know what you are doing but this is only for the advanced grower and even then many experienced growers don’t feel it shows enough increase in yield to make it worth the extra trouble or the added risk of bud-rot. The way most common for avoiding nutrients on your flowers is obvious, be very careful to only spray the fan leaves, maybe discontinuing using any nutrients and only r/o water the last couple weeks before harvest. Some will use the same technique spraying directly on the flowers and relying on those last couple of weeks to fully wash the flowers clean of any unused nutrients. Also when foliar feeding in general and especially where too much moisture in the air is of concern, the spraying should be done at the plant’s first light, this way they have the most time to dry out before the lights go out and it is believed the plants absorb nutrients better through the leaves in the dark as the surface pours of the plant are more open and at first light they might still be a little more open. Some growers will then even go to the extreme of using special green lights as not to disrupt the plants dark cycle and spray the plant about 10-15 minutes before the lights come on.

I need to chime in here. I’m in New Mexico, and am having a hell of a time keeping my indoor humidity up above 20%. My point being, if you wanted to try this spraying technique, one could artificially lower the humidity to a point where the addition moisture would not result in mold, and other yucky stuff.

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The only problem is; You need a micro fine mist in order to keep from damaging the foliage.

I agree in New Mexico you need to add humidity, but that does not mean you have to spritz the plant. You can merely set a bucket full of water beside a fan to moisten the air, with less chance of damaging the foliage.

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Just a random ‘brain fart’ - in most areas of the World, there is dew every night during growing season. Which serves to clean the leaves and stoma’s. This why I mist my plants everyday up to the time the buds get bigger, and have crevices and hidden surfaces that don’t get much air.

Yes, it’s always good to clean out your stomas. Under HID lights you could even mist the leaves with pure water and then gently wipe them dry with a clean lint free cloth or paper towel.

Totally agree, at 30%-35% RH your leaves and buds wont stay wet for more than 3-5 minutes and bone dry again. Would not risk misting past 35%RH. Lights will also not burn leaves at this RH, dries far too quickly to cause magnification burn. Mist with water that has set open for 5 days to off gas chlorine and chloramine for best results. Yields with misting improve ~ 10%-20% vs. 30% RH and no misting. If you are in a dry area, this is a very good strategy to increase yields. Just watch your RH and don’t mist during wet spells that cause the ambient RH to exceed 35%RH.

Is it necessary to mist your plants if the humidity is good?

I grow indoors under LED lighting in 10 gallon fabric pots with yields between 12 oz and 17 oz per plant.
I NEVER mist my plants. There are many growers that do mist their plants without issue.