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GROWER
by Monica Mansfield
Q
a
I’m growing leafy greens in my hydro system in my basement. What is the ideal
humidity level and what is the best way to control it? Thanks.
— Preston C.
Thank you for your question. The ideal relative
humidity for growing leafy greens is 50-70 percent.
To prevent mold and mildew from becoming an issue in
your basement, home experts recommend keeping your
basement between 50-60 percent.
It is crucial to maintain the proper humidity when
growing leafy greens. High humidity levels can cause
powdery mildew and tip burn. When humidity is too
high, it causes transpiration to occur more slowly, which
in turn slows the absorption of calcium. This calcium
deficiency causes tip burn.
Low humidity can cause an outer leaf edge burn. This
is a physiological disorder where lesions develop on
the veins on the outer edge of the leaves. It is caused
when sap exudes from the veins and then reabsorbs,
creating a salt buildup.
It is also important to keep your humidity level consistent.
Rapid changes in humidity can stress your plants and
cause tissue damage because the plant doesn’t have time
to adjust to changes in the environment. Rapid changes
usually happen when you flood the room with dry outdoor
air or from a sudden change in temperature.
When controlling humidity, keep a few key points
in mind. Cooler temperatures increase humidity,
while warmer temperatures decrease humidity.
The water from your hydro system may increase
humidity through evaporation, depending on the type
of system you’re using. The more plants you have, the
higher your humidity levels will be due to transpiration.
If you are exchanging your air, the humidity level of
the outdoor air you are bringing in will influence your
indoor humidity level.
A dehumidifier is going to be the best piece of equipment
to control humidity. Most dehumidifiers can be set to
maintain your humidity at the level you choose. Keep
in mind a dehumidifier will create heat in your room.
While this may be good for burning off excess moisture,
the heat from all your grow equipment can generate
too much heat, in which case you’ll need to find a way
to lower the temperature in your growroom. You can do
this by exchanging indoor and outdoor air with exhaust
fans, or by adding an air conditioner to your room. If you
exchange your air, be mindful of the temperature and
humidity outdoors, and how that may affect your indoor
environment. These factors are constantly changing, and
you’ll need to make adjustments regularly to balance
them so your humidity remains consistent.
Good luck and keep growing!
Monica Mansfield
MM
Monica Mansfield owned an indoor garden store for 5½ years before selling the business to start a seven-acre homestead
with her husband, Owen. Monica is passionate about gardening, sustainable living, and holistic health. She writes about these
topics and her homestead adventures on her blog, thenaturelifeproject.com.
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