What Is The Ideal Temperature For Growing Cannabis In A Greenhouse

If you don’t know what the ideal temperature for growing cannabis in a greenhouse that is 70 to 80°F, cultivating cannabis indoors is will be impossible. At the same time, remember that cultivation laws for cannabis are different for every state, and it’s essential to check them before growing the plants. Alaska, Colorado, Washington, Maine, Massachusetts, Michigan, Nevada, and Oregon are states that allow cultivation, but still, read the additional guidelines for each. 

Environmental control is a significant consideration when growing cannabis in a greenhouse. Like all plants you grow indoors, your plants’ survival is significantly affected by how well you can maintain optimal temperatures. Simultaneously, the cannabis plants are USDA hardiness 8 to 11, which can also give you a gist if your location will support their growth or more modifications in the greenhouse. 

What Is The Ideal Temperature For Growing Cannabis In A Greenhouse

Knowing What Is The Ideal Temperature For Growing Cannabis In A Greenhouse

To know the ideal temperature, take into consideration that cannabis plants formerly come from warm and dry locations. Therefore, the plants will have a hard time surviving if your state experiences harsh average temperatures. However, the Handbook of Energy Crops has also stated that cannabis is incredibly adaptable, making it an excellent greenhouse crop.

Below are the best air and soil temperatures for cannabis plants.


The best temperature for growing cannabis in a greenhouse and how to maintain it

The best temperature for growing cannabis in a greenhouse is at 70 to 80°F. Because of this, it’s best to sow your cannabis seeds in early spring in the greenhouse. The seeds will germinate at low temperatures, but be careful not to reach below 33.8°F since this condition will prevent germination. 

Overall, the greenhouse should not be extremely hot nor cold. Since you’re growing in a greenhouse, you also benefit from protecting cannabis from freezing weather due to the natural heat. However, you can always add a heating system if your location is freezing.  

As for controlling heat, you can practice ventilation and cooling systems to prevent buildup, especially if you experience harsh months. Some growers also recommend using CO2 injection and lighting to have more control in air temperatures. But what about the soil temperature for growing cannabis in a greenhouse?

Maintain 72 to 75°F on fertile, loamy soil to support your plants thoroughly. On the contrary, sandy and acidic soil will not work best for cannabis. And lastly, don’t forget to pick the appropriate varieties according to their intended usage like fiber, edible seed, and oil.


Is humidity control important for growing cannabis in a greenhouse?

Now that you know the optimal temperatures for air and soil in your greenhouse, is humidity important for growing cannabis? As you can expect, controlling the humidity also plays a role in the success of your cultivation. You already have a headstart in using a greenhouse to control the environment much more comfortably.

Aim to start seedlings and young cannabis plants at 60 to 70% because they prefer moisture. As they grow, you can reduce the humidity at 40%, especially during week nine, when your plants have flowered. Failure to check the humidity in the greenhouse can be detrimental because of the heat, mold, and other diseases.

So how can you control the humidity levels in the cannabis greenhouse? Vents, dehumidifiers, or automatic controls are the best solution for ensuring the optimal humidity level indoors. The latter would save you the trouble because some systems can automatically vent or dehumidify depending on the moisture levels.


Other Considerations For Growing Cannabis In A Greenhouse

Besides temperature and humidity, you want to consider lights, blackout systems, fans, and active carbon filters to address potential unwanted odors and other indoor limitations. You also want to ensure adequate space inside the greenhouse as you would, regardless of the plants you’re growing. Lastly, choose a greenhouse location facing west or south to provide excellent conditions. 


Why Use A Greenhouse For Cannabis?

For starters, growing cannabis in a greenhouse already protects your plants from the inconsistencies of outdoor conditions, and maybe even theft. A greenhouse ensures stable and consistent requirements for the optimal growth of the plants. And because of its enclosed design, you can keep off burglars. 

More importantly, the control you have on the climate will allow you to extend phases in the cannabis life cycle. You can even harvest much later or plant earlier to get several harvests in a year. With proper planning and maintenance, you can reap multiple benefits with greenhouse cultivation. 



Perhaps you’ve checked your state’s laws, and growing cannabis is something you want to pursue. You already have the greenhouse ready, but do you know what is the ideal temperature for growing cannabis in a greenhouse? Temperature and humidity control are crucial for the survival of cannabis plants, so always maintain the indoor conditions at 70 to 80°F and 40% humidity level when your plants have flowered. 

Overall, check your hardiness zone and study other considerations before cultivating cannabis. It’s also worth emphasizing that there are different laws for each state, which is the first factor that you must look into. Afterward, you can always use the advantage of a greenhouse in modifying the conditions that are suitable for cannabis plants. 


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