“ The winter months
allow for much more versatility
concerning the use of CO2, as colder weather plays an essential role
in keeping temperatures cool in growrooms.”
from a convenience standpoint; propane tanks can be filled
at almost any gas station, whereas CO2 tanks must be filled
at specialty shops. On another note, in the more novice and
traditional exhaust-based growroom set-up, CO2 enrichment
is often not even an option in the warm summer months.
Within this framework, environmental controllers dictate
whether the exhaust is pulling air out of the room or the
exhaust is off and the CO2 emission device is operational. As
these environmental controllers are dictated by temperature
and humidity levels, cooler temperatures allow for more CO2
emission with less use of the exhaust. In either scenario,
winter temperatures allow for a more constant level of high
CO2 in any indoor growroom.
HUMIDITY
Depending upon the outdoor climate of the operations in
question, winter weather generally means a higher humidity
level in growrooms for a couple of reasons. First, many
geographies have far more precipitation outside during
the winter months. Second, as the outdoor climate causes
temperatures in growrooms to drop to a certain level relative
to the amount of humidity in the air, the dew point in the
microatmosphere can become problematic. This phenomenon
occurs as the water vapor in the air (humidity) is released by
reaching a cold air temperature threshold. The solidification
of water vapor into condensed liquid form is referred to as
‘dew’ in the standard climatological lexicon. The formation of
dew within a growroom can lead to a number of cultivation
problems, including both powdery mildew and botrytis.
Therefore, the use of a dehumidifier in growrooms can help
counteract potential problems caused by both
outdoor precipitation and indoor humidity/dew
point during the winter months. To help offset
the cost of purchasing a dehumidifier strictly
for the winter months, units often double as air
conditioners to be used during the summer.
TEMPERATURE
With the influx of cold temperatures during the winter,
indoor gardeners are faced with the challenge of providing
consistent environments for their crops. Ideal indoor garden
temperatures should range between 72 - 76°F, and this
temperature range should be maintained with the lights both
on and off. This is because temperature fluctuations of more
than 15°F between “day” and “night” can contribute to the
dew issues mentioned earlier. Furthermore, if growrooms
reach temperatures below 55°F, plant growth is retarded and
even halted. To combat temperature fluctuations between day
and night in a growroom, it’s recommended that cultivators
utilize a heating device. Economically savvy growers will
look for heating devices that are multifunctional and can be
used, in some form, throughout the year. For example, some
mini-split air conditioning units can double as heaters in the
winter, allowing for the streamlining of the electrical load of a
growroom during all seasons.
SPIDER MITES
During all times of the
year, spider mites pose
a constant threat to the
health of any indoor
garden. However, the
higher temperatures in growrooms during
the summertime provide an ideal climate
for spider mite eggs to hatch and mature quickly. As indoor
gardeners have more options for regulating temperatures in
the winter months, they have a far better chance of controlling
spider mite populations than in summer. A growroom
maintained at 75°F in December provides a climate far less
conducive to spider mite growth and reproduction than a room
kept at 80°F in July, studies show. Therefore, slightly cooler
growroom temperatures in winter will work in unison with
organic sprays to effectively eradicate these harmful pests.
Kent Gruetzmacher is a California-based freelance writer and
the West Coast director of business development at Mac & Fulton
Executive Search and Consulting (mandfconsultants.com), an
employment recruiting firm dedicated to the indoor gardening
and hydroponics industry. He is interested in utilizing his M.A.
in the Humanities to critically explore the many cultural and
business facets of this youthful, emergent industry by way of his
entrepreneurial projects.
Maximum Yield USA | January 2017
135