When it comes to cannabis cultivation, greenhouses offer what outdoor growing can’t: total environmental control, increased energy and labor efficiency and, most importantly, maximized profits.
The ideal temperature for a cannabis plant at different stages of growth is dependent on the grower, but it should range from 65 to 85 degrees Fahrenheit (between 30 and 40 degrees Celsius). Sophisticated greenhouses use heating and cooling systems, automated watering and LED lighting to maintain these temperatures.
Temperature
In a greenhouse, temperature is one of the most important factors. It can influence nearly all processes in cannabis cultivation, including growth, development, yield, quality, and plant health.
Temperature can also affect the germination and development of seeds, as well as the drying and curing of buds. Keeping temperatures and relative humidity levels at their ideal levels is critical for successful grow results.
The optimal temperature for a greenhouse should be around 24-29 degC (75-85 degrees Fahrenheit). Higher temperatures stimulate the metabolism of plants, which can increase production and bud quality.
Another factor that impacts the temperature of a greenhouse is CO2 enrichment, which can help promote stronger flowering. In addition, a greenhouse can be equipped with automated environmental controls that monitor and control temperature, air movement, and moisture levels.
Many growers will turn on the lights during the day and leave them off at night to keep temperatures, humidity, and air circulation under control. This is a smart strategy for lowering energy costs and keeping the electric bill low.
It is also important to keep in mind that a difference of no more than 5degC between the day and night temperatures is ideal for marijuana. This will allow the plant to maximize its photosynthesis and ensure a healthy, happy crop.
The temperature of a greenhouse is particularly important during the vegetative stage of the plant’s life cycle. During this period, the plant is putting on new leaves and branches, expanding its root system, and feeding itself with water and nutrients.
Since cannabis plants require optimal nutrient absorption, their roots should be kept within a certain temperature range to facilitate the development of a strong root zone. This can be difficult to achieve if the grower does not regularly monitor and regulate the greenhouse’s environment.
Humidity is also vital for the proper development of cannabis, as it plays a role in a plants’ ability to absorb essential elements from the soil and other growing media. During the vegetative phase, the relative humidity should be between 60 and 70 percent.
During the flowering phase, the humidity should be lowered to 40 to 50 percent. This is a critical stage for many growers, as it helps to reduce stress on the plants and allows them to produce a high yield of top-quality buds.
Light
When growing cannabis in a greenhouse, it’s important to consider the available light. While some greenhouses can rely on natural sunlight to provide enough lighting, others need extra supplemental lighting to achieve optimal results.
In general, plants like different levels of light at different stages of growth. For example, early-blooming crops need less light than later bloomers.
Greenhouse growers can supplement natural sunlight with fixed spectrum LEDs, high-pressure sodium (HPS) lights or metal halide lamps that can offer increased light intensity. This enables you to get a higher yield and quality product from your cannabis crops without sacrificing their growth and flowering cycles.
Unlike growing outdoors, which is completely dependent on weather conditions, a greenhouse’s lighting system is fully automated and controlled. This allows you to keep your environment optimal for all types of plant growth and development, saving you energy and time.
The main benefit of using a smart greenhouse lighting system is the ability to adjust your lighting based on real-time environmental conditions. This can be done with Adaptive Controllers that detect shaded areas of your greenhouse and optimize the light levels.
Many greenhouses also use LED lighting, which offers greater energy efficiency than fluorescent bulbs and has a long life. These types of lamps also have a wider variety of lamp sizes, which can help reduce glare and create better light distribution for plants.
Another strategy is to use blackout curtains during the darkest hours of the day, which prevents light from escaping the greenhouse and can protect plants from re-vegging. The addition of these curtains can also reduce light pollution and make your greenhouse a more pleasant space to be in.
While there is a lot of difference between growing in a greenhouse and in an outdoor setting, most growers still need to be very vigilant with lighting and controls in their indoor facilities, as well. That’s because supplemental lighting has a much larger role to play than just providing additional light, according to Taylor Kirk, horticulture service specialist with Fluence by OSRAM.
Water
Water is an essential component of a successful cannabis cultivation operation. It is also a vital resource that must be used efficiently to reduce operational costs and maintain high quality yields.
Generally speaking, most greenhouses require ample water for multiple purposes. This includes a supply of clean drinking water to drink, irrigate plants, and cool the building. In addition, a variety of irrigation systems are available that offer automatic timers and controllers to water your cannabis crop when and where you want it to be.
Many of these devices are Wi-Fi enabled and can be set via your phone so that you can monitor and control parameters from anywhere in the world. Other options include slow drip systems that provide a constant trickle of water to your plants.
The type of water you use for your cannabis crops can make a huge difference in your yields, so it’s important to consider the quality of your water before committing to using it. You can test your water’s pH, minerals, and turbidity levels to ensure that you have water that is optimal for plant growth.
For example, you may have water from the ground (well water) that is full of calcium and magnesium that can impede root growth and nutrient absorption, or you might have city-water that is too alkaline for your plants’ needs. Having a clear understanding of your water’s quality before you begin your cannabis cultivation process will give you peace of mind and allow you to experiment with nutrient solutions with confidence.
If your water comes from the city, you should test it for chlorine and chloramine, which can impede root growth and cause nutrient deficiencies. For this reason, it’s a good idea to invest in water filtration systems.
It’s also a good idea to have your water tested for contaminants such as copper, lead, and arsenic that can corrode the pipes in your greenhouse. Having a water testing system in place can save you money in the long run by ensuring that your pipes are not damaged and that you have access to safe, clean, high-quality water for all of your operations.
Air
Whether you’re starting a small grow shop or a large cannabis enterprise, greenhouses offer the perfect growing environment. With the right design and system, greenhouses can help you maximize plant production, saving time and money while reducing your carbon footprint.
Air Quality in Greenhouses
The air in a greenhouse is essential to growing healthy plants. Air filtration is the best way to ensure clean air in your growing room. Regularly replacing filters is important to keep your grow room running at peak efficiency.
Temperature and humidity are two environmental factors that can affect plant health in a cannabis greenhouse. Keeping temperatures in the 70degF to 80degF range will keep your plants happy and healthy.
Air filtration in a greenhouse is also important to reduce odors and harmful microorganisms. The right system is able to eliminate airborne contaminants, including bacteria, viruses, molds and fungi.
In addition to the proper air filtration, a cannabis grower should have adequate ventilation. Without good ventilation, a cannabis greenhouse can become humid and cause problems such as mold or bud rot.
A greenhouse should be positioned in such a way that the largest side receives maximum sunlight. If possible, position your greenhouse east to west so that the biggest side will receive direct sun throughout the day.
Another critical aspect of a greenhouse is ensuring the water quality is high enough to support cannabis growth. Regardless of your local water supply, it’s crucial to test for minerals and other deficiencies. Choosing the right irrigation system is a key factor in successful cultivation.
If you’re preparing to build a greenhouse for cannabis, choose the best material for your needs. Glass is traditional, but you can also use fiberglass and plastic. The greenhouse material you choose should be able to withstand heat, wind, snow, and water loading.
Once the structure is built, consider the type of climate control you want for your marijuana growing facility. You’ll need to decide how many plants you’ll be growing and what size greenhouse you need.
Climate control is a vital part of any commercial grow room, but it’s especially important when growing medical cannabis. It not only creates optimal growing conditions for your crops, it serves as a pest management tool. A combination of structure components, sensors, and a smart controller helps keep your cannabis greenhouse healthy and pest-free.
