Deserts cover approximately one fifth of the Earth’s surface. When most people think of deserts, they picture large sand dunes and camels like those of the Sahara, but in fact, there are four types of deserts: subtropical deserts, coastal deserts, cold winter deserts, and polar deserts. In the US, all the deserts — the Chihuahuan, Sonoran, Mojave, and Great Basin — are considered subtropical. Subtropical deserts are categorically dry year-round and can get to deathly high temperatures during peak summer months. Rainfall happens rarely and usually only in short bursts. The soil in subtropical deserts is usually either sandy or coarse and rocky and very warm.
As far as deserts go, the Mojave Desert is unusually dearth of vegetation beyond cacti and tumbleweed. It happens to be the most arid environment in North America. However, if you drive to the outskirts of Las Vegas towards the growing operations which supply the city with its latest and hottest commodity — cannabis — you may be surprised to see that plants can be grown anywhere with a little bit of creativity.
Since Nevada legalized adult-use cannabis in 2016, growers in Las Vegas have consistently been proving that potent indoor strains of cannabis can be cultivated and nurtured in a harsh desert environment. Las Vegas is home to the first pioneers of desert greenhouse cannabis growing in the world. These pioneers include hybrid greenhouse projects, traditional greenhouse projects, and an outdoor-style, mesh-tent grow. All these operations are currently cultivating top-shelf cannabis in the Mojave.
Hybrid Greenhouse Operations
Hybrid greenhouses incorporate a style of cultivation that combines tightly controlled indoor growing conditions and the natural abundance of sunlight offered to outdoor growing. These designs are typically very high-tech and provide for the ability to control all aspects of the environment, which in turn allows for higher, more sensitive genetics to be cultivated. Data is also easier to accumulate and analyze since the environment is more stabilized.
Las Vegas is also home to the most stringent cannabis testing rules on molds and contaminates. Even though the dry environment of the Mojave has geographically low mold counts, we still have airborne molds with June being the high season. Las Vegas also has pests that can smell the sweet cannabis and water for miles, so proper camouflage, treatment, and beneficial microbes need consistent applications. Hybrid greenhouses use technology mostly to combat these.
In general, hybrid-greenhouses are also highly automated. They typically use air-scrubbing technologies for dehumidification (yes, even in a desert) to try control the environments in a very tight range. Their yields can be larger per square foot due to efficiencies and adaptive lighting. The latest hybrid design is the first ground-up hybrid greenhouse for cannabis and one of the largest cultivation facilities in Nevada. It combines an elevated central spline air intake with evaporative cooling and twin-polycarbonate roof to draw as much sunlight as possible yet keep cooling costs lower by taking advantage of the dry environment and avoiding traditional AC units. The design has broken the ceiling on proving indoor quality cannabis can be produced at lower costs and are producing cannabis genetics ranging from 16-30 per cent THC levels, more than 28 per cent total cannabinoids, and terpenes well above 15-25 mg/g. The construction was well under indoor average at $150 per sq. ft. and running costs at less than $300 per pound. Insect Pest Management (IPM) exists more in the technology of these grows than simple sprays like others.
Passing rates are also significantly high as technology is combined to clean the interior of mold and prevent pests from entering or breeding. Operational costs, although higher than outdoor growing, require less grow staff due to automation and cleaning protocols to keep the environment pristine. Hybrid greenhouses combine industrial-grow sizing with higher care commensurate with connoisseur artisan grow techniques.
Traditional Greenhouse Operations
Of the few traditional greenhouse operations originally built in the Mojave, all exhibit traditional poly-film and polycarbonate roofs with aluminum side walls. With a capital expense that ranges from roughly $50 to $100 per sq. ft. and around $400 per pound in costs. These structures can achieve perpetual harvest schedules with their lighting grids and blackout curtains.
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These designs are exhibiting THC levels historically around 14-24 per cent, with around 26 per cent total cannabinoid counts and terpene profiles that show promise around 12-18 mg/g. These grows have traditional greenhouse wet-pad and heating systems to combat the 115°F heat and 32°F-cold to control the environment properly. They also have the traditional door entrances and pad walls open to the outside. All these traditional structures are more than an hour drive from Las Vegas and are located over the third-largest aquifer in the US, so free water is clearly a large benefit which more than offsets any additional IPM needed deeper into the Mojave. They also require long drives and/or specialized housing for growers and employees.
Mesh Cover Operations
The first outdoor desert cannabis cultivation operation in Nevada just finished harvesting its second crop. This operation utilizes a fully enclosed mesh tent with dirt floors and no lighting system. This kind of structure has a capital expenditure of around $17 per sq. ft. (most costs are specialized cannabis security needs) and can only do one or two crops a year with growing costs of around $150 per pound. The recent results have shown THC levels between 13-23 per cent, around 24 per cent total cannabinoid count, and total terpenes around 10-15 mg/g.
After their first summer grow, they have proven that simple mesh can protect the plants from the harsh summer sun, regular 30-90 mph wind storms that occur in the deep desert, and most importantly, that cannabinoids can be produced under extreme heat and cold night conditions with no environmentals. The first cycle occurred from May to November, and they are gearing up for a winter 2020 cycle, which will be interesting to see the results. For this style grow, the IPM is constant and heavy. The same antifungals and preventative pest maintenance, plus addition of beneficials, exist like the traditional greenhouse growers. With a great IPM and pre-drying cleaning protocol, passing results can indeed be achieved with a highly simplified structure practically open to all elements.
Read also: Beginner's Guide to Beneficial Insects
All these pioneers know one thing: growing in a desert is not easy and requires patience as you dial in your genetics, equipment, and grow styles. Fast-shifting weather and seasons, high windstorms, hungry pests starving in the desert looking for water, and even molds make for a challenging grow environment. But the desert has a lot of light, thus it’s no wonder people are investing in desert growing in Vegas, Arizona, and huge projects in the California desert. But please, make sure there is lots of available water because few things can survive a waterless desert and cannabis needs more water for the plants and water for evaporative cooling than most indigenous desert species.