While choosing cannabis flowers, in addition to health, visual and aromatic values, plant’s cultivation method can also be an important deteminant. Each legal batch is marked as outdoor, greenhouse or indoor – but what does it actually mean? Why the same strain, cultivated in different ways, can have an extremely different price and a multitude of supporters on each side? As for the best way to produce this plant, it’s hard to get a clear verdict – undoubtedly all types of cannabis cultivation have their pros and cons. In this article, we will try to present the characteristics of each of them, as well as the characteristics of plants grown in different environments.
Outdoor, or field cultivation
Once, before cannabis was broadly banned by law, all of its crops were grown in the fields. Today, for several reasons, even the producers of hemp containing trace amounts of psychoactive substances, often give up growing in the open. They have several drawbacks.
First of all, outdoor plants, i.e. grown in the field, depend on weather conditions. Given that you can usually only harvest one yield per year from a single field, relying on favorable weather conditions can be somehow like playing a roulette (especially in recent years). Thus, producers (who have capital) often choose better controlled cannabis cultivations. However, this isn’t always a better solution.
It turns out that the production of cannabinoids and terpenes, i.e. the most important health-promoting substances in cannabis, is the highest in the presence of natural light . This is probably because, unlike artificial lighting, sunlight (therefore also the one reflected from the moon) represents the entire wavelength spectrum. Some believe  that plants grown outdoors are healthier because they don’t require intensive fertilization and increased use of pesticides. Such substances can be harmful to health ingested or inhaled in high concentrations.
Indoor, or under-the-roof cultivation
Despite this, in some US states, outdoor cultivation of medical cannabis has been banned by law due to the inability to control growth conditions. Indoor cultivation is definitely more expensive (for both the consumer and the environment), but allows the best control over all key parameters for a growing plant. It’s thus possible to processes standarization and repeatability of the expected quality and flowers’ characteristics. For this reason, consumers appreciate high-quality indoor flowers, which almost always look and smell the same.
An important point is that a large proportion of “genetically new” strains simply grow better in indoor conditions. Importantly, for people involved in hemp production, indoor cultivation provides greater yields than any other type of cannabis cultivation – as many as 4-8 a year.
Indoor cannabis cultivation, however, requires knowledge and mindfulness. In such a model it’s more difficult to get rid of possible pathogens. It’s also easy to allow other oversights, e.g. regarding the amount of carbon dioxide in the air that can seriously harm plants .
Greenhouse, or glasshouse cultivation
A kind of bridge, or middle ground, between indoor and outdoor is greenhouse cultivation. Some say it’s the best way to grow cannabis, because it allows you to preserve the best features of both other methods, excluding the negative elements.
Greenhouse cultivation doesn’t allow full control over environmental conditions. Whereas it allows you to look after some key parameters, such as temperature and possible light deprivation. Thus, you can usually harvest two yields a year from this type cannabis cultivation. As plants can still benefit from natural sunlight in greenhouses, their aromas are similar to those grown outdoors.
The construction and equipment of greenhouses is obviously more expensive than growing plants in the field. Nonetheless, it’s still much cheaper than adapting the infrastructure for indoor cultivation.
Cannabis cultivation types and their ecological footprint
Despite the advantage of indoor cultivation in terms of optimization and repeatability, it definitely lags behind when it comes to balancing environmental costs. Outdoor cultivation is much better here. First of all, its carbon footprint is much lower than the one that characterizes other types of cannabis cultivation. Plants don’t have to be irradiated, we don’t have to remove moisture or ventilate surrounding air as well.
On average, 1 kg of cannabis cultivated indoors is associated with the emission of 4,600 kg of carbon dioxide into the atmosphere . What’s more, in the United States, indoor hemp consumes as much as 1% of annual electricity consumption for the entire country . Such data, however, comes from 8 years ago. Given the dynamic development of the cannabis market, we can safely assume that today this value is higher. Of course, indoor crop owners can use energy-sustainable solutions, such as photovoltaics. Still, in the race for the lowest ecological footprint, at least at the moment, outdoor cannabis cultivation wins.
Compared to indoor cannabis, those growing in the natural sun usually also require less fertilizer, pesticides and fungicides . Thanks to this, the process itself is more environmentally friendly as well as simply cheaper. However, the choice for cultivators and consumers remains an individual matter – there is no perfect solution to meet every need.
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