This post is also available in: English
As mentionned in previous articles, growing cannabis outside under modern greenhouse has many advantages.
Using passive and active ventilation strategies inside the greenhouse allow the grower to control the relative humidity concentration inside the growing area. Indeed, during the biological development of the plant, it will release into the environment much of the water it has absorbed. This phenomenon is called evapotranspiration. An excess of humidity will affect the growth of the crop and promote the appearance of diseases (mold, mildew…).
We will see in this article more particularly the importance of the black out system to create a light deprivation.
In a open-field hemp or cannabis farm, growers are dependant to the outside weather to cultivate the cannabis. Because of the temperature, rainfall, light, pests and diseases… it is difficult to predict the yield and the number of production cycles during the year.
In fact, inside a high-tech greenhouse, the technology and equipment will secure the production and help the farm manager and investors to build a business plan with less uncertainty.
Why do we need to use a black out cover to grow cannabis / hemp ?
The control of the photoperiod is an important point for the grower. Indeed, a 12h day / 12h night cycle required for the cannabis crops flowering.
Using the right greenhouse and black out covering you will be able to manage the poduction all year round increasing the yields. Nowadays, it is possible to link the black out system to the climate control computer to have an accurate light deprivation management and data record.
To be efficient the black out technology inside your greenhouse must reach more than 95-99% light reduction, meaning almost complete darkness. The key point is to select the right greenhouse design (frame) equipped with an effective light deprivation system without light linkage. Some greenhouse manufacturers and builders have dedicated solution.
The ligh deprivation installation must cover totally the side walls and the roof of the greenhouse keeping enough volume to manage the RH %, temperature, air flow… The connection with the frame, the cost of the black out and the maintenance are important factors to consider…
Another advantage of the black out cover is to have thermal propriety in the cover (clothe) to keep the heat inside the greenhouse when the outside temperature drops. It is an ernergy saving option to reduce the heating cost.