PPM Question
- Thread starter Trippyness
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Plants and Humidity: Introduction
A common misconception in indoor gardening revolves around the idea that plants do not like high levels of humidity. This quite simply isn’t true! Plants love high humidity (especially in vegetative growth), but all too often indoor growers create low humidity environments to avoid potential pathogens that are not really an issue until the flowering stage. This “play it safe” attitude is understandable as nobody wants to have a fungal or bacterial problem but through careful humidity management throughout your plants growth you can avoid any such problems whilst also significantly improving your growth rates.
Plants and Humidity: The Science
Your plants’ ability to remain suitably hydrated and capable of absorbing the necessary nutrients for growth greatly depends on how efficient water transportation is within their systems. The humidity of your growing environment can potentially disrupt this process as it is a controlling factor on how much moisture transpires from your plants and therefore how water is moving through the plant from roots to leaves.
To understand the effect of humidity on water transport there are a couple of points you need to understand. Firstly, water tends to move from high humidity areas to low humidity areas. Secondly, the humidity inside plants has been found close to 100%. The rate at which water leaves your plants (via transpiration) will increase the lower the humidity in your grow room. Since the humidity inside your plants falls in the region of 100%, the humidity of the growing environment will also need to be relatively high to avoid potentially damaging over transpiration. This is particularly relevant before fruits and flowers begin to form.
Obviously, if humidity is very low then plants will lose too much water leading to the threat of damage caused by dryness. Consequently, the development of new leaves may suffer, older leaves could curl or even shed, and flowers/fruit occasionally die before or soon after opening.
Whilst low humidity is obviously not desirable, high humidity can cause problems too. Excessively high humidity and serious lack of ventilation sometimes encourages the spread of fungal diseases including Botrytis (Bud Rot) and Mildew, as well as stem and root infections in the very worst cases. However, with a reasonable amount of care and the right equipment this scenario is very easy to avoid.
A common misconception in indoor gardening revolves around the idea that plants do not like high levels of humidity. This quite simply isn’t true! Plants love high humidity (especially in vegetative growth), but all too often indoor growers create low humidity environments to avoid potential pathogens that are not really an issue until the flowering stage. This “play it safe” attitude is understandable as nobody wants to have a fungal or bacterial problem but through careful humidity management throughout your plants growth you can avoid any such problems whilst also significantly improving your growth rates.
Plants and Humidity: The Science
Your plants’ ability to remain suitably hydrated and capable of absorbing the necessary nutrients for growth greatly depends on how efficient water transportation is within their systems. The humidity of your growing environment can potentially disrupt this process as it is a controlling factor on how much moisture transpires from your plants and therefore how water is moving through the plant from roots to leaves.
To understand the effect of humidity on water transport there are a couple of points you need to understand. Firstly, water tends to move from high humidity areas to low humidity areas. Secondly, the humidity inside plants has been found close to 100%. The rate at which water leaves your plants (via transpiration) will increase the lower the humidity in your grow room. Since the humidity inside your plants falls in the region of 100%, the humidity of the growing environment will also need to be relatively high to avoid potentially damaging over transpiration. This is particularly relevant before fruits and flowers begin to form.
Obviously, if humidity is very low then plants will lose too much water leading to the threat of damage caused by dryness. Consequently, the development of new leaves may suffer, older leaves could curl or even shed, and flowers/fruit occasionally die before or soon after opening.
Whilst low humidity is obviously not desirable, high humidity can cause problems too. Excessively high humidity and serious lack of ventilation sometimes encourages the spread of fungal diseases including Botrytis (Bud Rot) and Mildew, as well as stem and root infections in the very worst cases. However, with a reasonable amount of care and the right equipment this scenario is very easy to avoid.
WeedFreak78
Well-Known Member
Drier conditions promote transpiration, which causes more water/nutrient uptake. We are trying to provide optimal conditions for max nutrient uptake to promote max growth. Humidity is just one factor we control. My flower room is usually around 30%RH and my veg is around 35-40%%RH. I think your medium will effect what RH you want, certain types of hydro ( dwc, nft, any constant recirculating system) plants can deal with lower RH than soil due to the amount of water available to them.