Greenhouses are the perfect environment to grow cannabis because they allow you to take advantage of natural sunlight. This is a big deal for cultivators because it means more consistent harvests and lower electricity costs.
However, greenhouses also require a lot of extra care and attention. You need to make sure that you have the right temperature, the best lighting, and plenty of water.
Temperature
Cannabis plants are sensitive to temperature, and growers need to be careful about how they set up the greenhouse. Temperatures should be between 20 and 30 degrees Celsius (68-85 degrees Fahrenheit).
Cannabis plant growth can slow down if the temperature is too high or cold. The plants’ photosynthesis cannot take place at the proper temperature, which can result in stunted growth.
In addition, hot temperatures can cause your cannabis plants to suffer from white powdery mildew and spider mites. These insects tend to thrive in warm conditions, as they feed off your cannabis’s roots and foliage.
Your cannabis plants will also struggle to absorb and use the nutrients they need if they’re in a hot climate, as this can lead to nutrient burn and other problems.
The ideal grow room temperature for cannabis plants is around 24degC (76F) during the day, and slightly lower at night. This keeps your cannabis root system hydrated and healthy, which will help them produce the best buds possible.
Once your cannabis plants reach the flowering stage, you’ll want to keep the temperature slightly higher than during the vegetative phase at 70 to 85degF (20-30degC). The flowers will develop more quickly and a higher quality of buds will be produced, so it’s important to keep the temperature at this level throughout the flowering stage.
The ideal humidity for cannabis plants during the vegetative and flowering stages is between 40 to 70 percent. You should lower the humidity by about five percent each week during this period.
Light
Cannabis plants require a specific amount of light throughout the entire growing process. Typically, they need at least 18 hours of light during the vegetative stage and only 6 hours during flowering.
This is why it is important to have the right grow lights for your greenhouse. The best grow lights will provide the correct light intensity to help your plants develop to their full potential.
Having a good lighting system will ensure that your cannabis plants are getting all the light they need to thrive and produce high-quality buds. Greenhouses also allow growers to add an extra grow light to supplement natural sunlight if needed.
Another advantage of greenhouses is that they can be used in the winter and during periods of cloudy weather. This can mean that you don’t have to worry about your harvest being impacted if the weather is bad.
It’s also a good idea to install a fan in your greenhouse to move air around and to push the humid air out of your door or roof vents. This will reduce humidity and keep your cannabis buds healthy.
Finally, it’s a good idea to limit the amount of light that escapes from your greenhouse to protect the environment. This isn’t too difficult to do, as you can use retractable blackout screens and window coverings.
A light intensity of 1800 PPFD (photons per meter squared) is the ideal level for cannabis plants to thrive at, according to Kirk. It is possible to reach higher levels, but this will only have a limited impact on the yields of your plant.
Water
Water is a critical part of cannabis cultivation, a key factor in ensuring that your plants grow and thrive. You need to strike the perfect balance between moisture and nutrients. The wrong amount of either can reduce your yields or encourage microbial growth that can harm the plant.
Using water efficiently can help you cut back on your costs and improve your greenhouse’s sustainability. Greenhouses can be equipped with irrigation systems that use drip technology and sensor-based controls to control watering cycles and conserve water.
Another option is to capture condensate from HVACD equipment and reclaim it for irrigation or other uses. This approach has been shown to reduce water usage by 30% to 70% and improve water productivity by 20% to 90%.
You can also use a variety of water treatment technologies to ensure that your water is free from contaminants. A popular choice is reverse osmosis (RO), which removes unwanted contaminants like chlorine and salt, as well as heavy metals and other contaminants that can be harmful to cannabis.
To further enhance the water quality of their irrigated plants, many cultivators turn to a method known as fertigation. This process uses a nutrient injection system to inject water with a specific nutrient ratio directly into the growing media.
Once the nutrient mixture has been prepared, the injected water is circulated through the growing media to supply the cannabis plant with the necessary nutrients. A variety of different nutrient combinations can be used to give your plants the proper nutrition that they need to achieve maximum potential.
In addition to a robust water management system, the right climate control system can also have a big impact on your greenhouse’s efficiency and success. This involves establishing a proper air circulation and controlling temperature and humidity levels.
Fertilizer
Fertilizers are used for a number of reasons, but primarily to increase the plant’s yield. They help to keep the plant strong, healthy and growing fast. They can also help the plant to produce the desired amount of THC and CBD, the two major cannabinoids in cannabis.
When choosing a fertilizer, it’s important to read the product label and follow its dosage guide or schedule. You need to avoid over-feeding your plants, which can lead to nutrient deficiency and reduced plant growth.
Some growers use organic fertilizers or other non-chemical alternatives. These are generally less toxic to the environment, and some are more forgiving to your plants than chemical alternatives.
Organic fertilizers can be made from compost, worm castings, manures or animal byproducts that have been broken down into readily available nutrients. These can be added to the soil before planting or potting up plants.
Using a good quality soil mix is important for the success of any greenhouse crop. Soil that is moist and rich in nutrients is ideal for a successful grow.
You can purchase a high-quality cannabis soil mix from your local nursery or make your own from locally available organic materials. It should be able to support a wide range of strains, and provide the ideal balance of micronutrients needed for the plants to thrive.
Unlike other crops, cannabis requires a specific ratio of the three primary plant nutrients – nitrogen (N), phosphorus (P) and potassium (K) – throughout its life cycle. This is known as the NPK ratio and is usually listed on the fertilizer’s label.
Security
If you want to use greenhouses for cannabis cultivation, you need to ensure that the security measures in place are compliant with Part 4 of the Cannabis Regulations. These regulations require that physical security measures are implemented in all operations areas and storage areas of a site.
You should also have a procedure in place for storing records of any detected occurrences that are recorded in the physical security logbook at your site. This will help you identify any security breaches or potential threats that may have occurred at your site.
Another key issue to consider when growing cannabis in a greenhouse is the security of your plants. You should have fencing in place that prevents anyone from coming into the greenhouse and potentially tampering with your marijuana plants. This is especially important if you live in an area where people might be concerned about marijuana being in the air or on the ground, or if you live in a neighborhood where it’s possible that neighbors could see your greenhouse.
It is essential to note that many counties have specific requirements for fencing in cannabis greenhouses, such as six-foot solid fencing that can be made of wood, masonry or similar material. The fence should be positioned so that it keeps people out but still allows sunlight to enter the greenhouse and allow your plants to grow.
In addition to ensuring that the greenhouse is secure, you should also make sure that all of your lighting and ventilation systems are properly controlled and automated by smart greenhouse controls. This will reduce your costs while maintaining the optimal environment for your cannabis plants. A greenhouse control system can be used to automate heating, cooling, lighting, shade systems, fertigation, ventilation and irrigation.
