Cannabis and Humidity

Cannabis and Humidity

----------------------------------------------------------

  In this short post you will learn why humidity matters and what your humidity should be in each growing stage. When starting your Cannabis plants, a lot of guys choose to use Humidity domes during the seedling stage to keep them in a constant RH (Relative Humidity) zone of 60-70% allowing more water to be absorbed through the leaves.  One negative thing about these domes is you block out airflow and have a higher chance of mold and fungus growth into the growing medium. As soon as you see finger leaves growing after the Cotyledons this is when you'd want to remove. 

During the vegetation stage the gardens RH will need to be lowered slowly to keep it within the acceptable 45-60% range. The reason why we do this is because the cannabis plant already has an established root system that absorbs most of the plants required water. 

Finally the last stage of a growing cannabis plant, the beautiful flowering stage. This is where we need to be careful because any high amounts of moisture can cause white mold, bud rot, and other diseases. A respectable range for early flowering is 40-55% and for late flowering 1-2 weeks before harvest 40-45% to significantly deduce any risks that might happen. 

Cotyledons - The first set of leaves that appear on on Seedling (Round Ones)

Picture By :

. . . . .

Saw this post on another forum about Seedlings and Humidity Domes and couldn't have said it any better. 

"Humidity domes simply keep the medium from drying too quickly when you are using heat mats to aid germination. Heat mats are designed to raise the temperature 10-15 degrees F above room temperature (to around 80 degrees) and this aids in germination and root development. Humidity is not so much a factor in germination as root zone temperature is. 
Be cautious when using a humidity dome because the medium can also become too wet which will actually slow root growth from lack of oxygen or create fungal problems. In my opinion, humidity domes and heat mats are really only useful for cuttings because they have no intention of forming roots and you must make every effort to force them to create them via rooting hormones, heat mats, humidity domes, etc. The tap root of a seed on the other hand intends to form roots and will even without the aid of a humidity dome.
Once the seedlings have there true leaves (first set of 1 finger leaves above the cotyledons) then remove the humidity dome."