Medical cannabis cultivated indoors is generally considered to be of higher quality than that grown outdoors. Because outdoor cannabis is cultivated on a much bigger scale, plants don't tend to be as fully developed as indoor cannabis, and consist of more leaves. However, good quality cannabis plants can be grown both indoors and outdoors, so long as some basic requirements are met.
Benefits of Growing Medical Cannabis in a Greenhouse
Strong winds and heavy rainfall can quickly destroy cannabis plants, so when grown outdoors it is essential for growers to give them some form of protection against these destructive elements. A greenhouse will not only offer cannabis protection from rain and wind, but because it is a closed environment, it makes controlling environmental factors necessary to facilitate the growth of healthy plants possible.
However, cannabis grown indoors requires an entirely different system of cultivation. Greenhouses that utilize a combination of fans to draw in a fresh supply of cool, clean air and expel hot, foul smelling air produce the best crops. Carbon filters can be fitted to extraction fans if foul odors may present an issue with neighbors.
While there is less chance for pests to gain access to cannabis plants grown indoors, they will still need to be rigorously managed to eliminate any pests, as in the absence of natural predators, insect pests will quickly devour cannabis leaves and destroy plants.
Controlling the Atmosphere
All plants need four essential ingredients for photosynthesis: light, nutrients, water and carbon dioxide. When growing medical cannabis inside a greenhouse, the grower needs to maintain the atmosphere so that conditions are optimal for growing cannabis. This includes ensuring that plants have sufficient light, water and nutrients necessary for growth, and maintaining air temperature and carbon dioxide at levels that stimulate plant growth.
The optimal daytime temperature range for growing cannabis is between 75-86 °F (24-30 °C). Carbon dioxide is very often the limiting factor in cannabis cultivation. No matter how much light, nutrients and water your crops get, if they don't get sufficient carbon dioxide, they will not thrive. Consequently, many cannabis growers provide supplementary carbon dioxide to encourage rapid growth. However, in order to plants to be able to make use of the additional carbon dioxide, the temperature in the greenhouse needs to be increased from 75 °F (24 °C) to between 80-85 °F (27-29 °C) to speed up the metabolic rate of the plants.
Measuring Air Quality
In order to maintain the atmosphere within the growth environment at optimal levels, medical cannabis growers need some way of measuring and monitoring the key variables within it. The Indoor Air Quality Meter/Datalogger
is a handy tool that does precisely that. The air quality meter records temperature, carbon dioxide, humidity, dew point and wet bulb; automatically logging up to 20,000 data sets, or allowing the grower to manually store and recall up to 99 data sets. The portable hand-held device comes complete with 6 x AAA batteries, RS-232 cable, and software that is compatible with Windows ® 95/98/NT/2000/ME/XP that facilitates downloading the recorded data onto a computer. It is suitable for multiple applications, but is particularly useful for monitoring air quality within a cannabis greenhouse.
Photo Credit: Scott Beale / Laughing Squid