Temperature and humidity are major factors when it comes to growing weed. If your temperature is too high to low, it can affect your yield, and could potentially kill your plants. The temperature and humidity can change according to what growing stage your plants are in. Make sure you have read up about cannabis plant life cycles. You will have to take care of several factors if you wish to grow cannabis indoors. We already covered the importance of lights in a previous blog. In this article, we’ll discuss the best temperature and humidity for growing weed. We will also teach you how to raise and lower your temperature and humidity. Thank you for choosing to learn with Skunk Magazine.
The Connection Between Humidity Levels and TemperatureImage Courtesy of Contentdealer – stock.adobe.com
We’re discussing these two factors in this article because they’re both connected. When we refer to humidity, we’re talking about relative humidity, which is defined as the ratio of the maximum vapor pressure of water to the ratio of partial pressure of water vapor at the same temperature.
Refer to your science classes – warm air can hold more vapor than cold air. This is why it’s important to extract warm air from your indoor garden to ensure the atmosphere is productive to your plants.
Best Temperature for Cannabis Plants?
Cannabis plants grow well between 70-85 when the lights are on. You can decrease the temperature a little when the lights are off. However, the exact temperature depends largely on what stage your plant is.
Here’s a breakdown:
#1 Seedling Stage
If you are starting to grow plants then you will need to keep the temperature between 68 to 77 Fahrenheit when the lights are on. Bring it down to about 60 Fahrenheit when the lights are off.
Clones and seeds grow well when humidity levels are between 65 to 70 percent. This is because the root system isn’t fully developed at this stage. High levels of humidity improve water intake through leaves and allow the plant to grow well.
#2 Vegetation Stage
This is the second stage and you will make some changes here to ensure the plant grows well and gives you the results that you expect. Keep the temperature between 71 to 82 Fahrenheit when the lights are on. Bring it down to about 64 Fahrenheit when the lights are off.
However, you may choose to increase temperatures a little during this time depending on the situation. This is the phase when roots begin to absorb more water.
Humidity levels should be lowered – about 5 percent each week – but stay in the range of 40 to 70 percent.
#3 Flowering Stage
You will have to take some very important steps at this stage to ensure the plant blossoms. Keep the temperature between 68 to 78 Fahrenheit. You do not have to change temperatures when the lights are off.
It’s best to avoid very high temperatures as weed tends to produce better results during this stage when temperatures are slightly lower.
Also, keep humidity levels between 40 to 50 percent and make sure to never go above 55 percent as it can damage the plant.
#4 Late FloweringImage Courtesy of Contentdealer – stock.adobe.com
Very few people pay attention to this stage. It occurs about 2 weeks before harvest and needs some changes to improve yield. In addition to this, we have found that making some changes at this stage can positively impact appearance and flavor as well.
These changes are not mandatory but if you want higher returns then you should take these steps. keep humidity levels between 30 to 40 percent.
It is best to temperatures between 64 to 75 Fahrenheit. Slightly lower daytime temperatures for better results.
How to Raise Humidity
- You can use a spray bottle to manually increase humidity. However, this option is not very long lasting.
- Make sure to keep the soil moist but never overwater. It should not be wet.
- You can hang wet clothes/towels in your space as a cheap solution.
- Keeping open water containers in the area can help increase humidity.
- Put your money in a humidifier. It’s best to opt for one with a large tank as ones with smaller tanks require a lot of refills.
How to Lower Humidity
- Increase fresh air supply.
- It’s best to water your plants right after you switch the lights on.
- Consider investing in a dehumidifier.
How to Raise Temperatures
- Opt for a bigger grow light since more watts equal to more heat.
- Consider investing in a heating mat to be kept in your grow room.
- Place a space heater in the room.
How to Lower Temperatures
- The best way to lower temperature is to increase the total airflow by letting more warm air to vent out. Installing vents can be a very good way to do so.
- They can push hot air out of the space. Some people also use fans but it is best to avoid using them as they only push air around and do not cool the air.
- Evaporative coolers and ACs can be very effective in bringing the temperature down. However, they can add to the cost since they’re expensive and use a lot of power as well.
- It is best to use a cool tube if you use HPS lights.
- Change your light schedule according to the changing climate and your plant’s growth.
If you didn’t already know best temperature and humidity for growing weed, we suggest reading some more articles before stating your own grow op.