Hemp temperature stress

An extremely important task for any marijuana grower is to ensure and maintain temperatures within the desired range. This greatly affects the ability of plants to photosynthesize (chlorophyll production) and, accordingly, their growth.

What is the optimal temperature for marijuana?

The light-independent reactions of photosynthesis in hemp are catalyzed by specific enzymes that function at specific temperatures. Therefore, plants that grow in ideal temperature conditions will produce chlorophyll faster.

When growing bushes, the optimum temperature and humidity for marijuana should be maintained, and there should be no drafts. During the day, it grows best at temperatures that range from 20-30°C. At night the plant likes temperatures around 18°C. The ideal humidity level is 65-70%.

Sativa-dominant varieties, during the period of bud formation, tolerate higher temperatures and higher air humidity than Indica-dominant varieties. This may be a better option for growing indoors in the summer when temperatures often rise.

What happens when the temperature is too high?

High temperatures are less of a concern than low temperatures because cannabis plants are very rarely killed by the heat. However, the critical temperature for marijuana is more than 35°C, as it results in slow plant growth because the enzymes involved in the process of photosynthesis cannot work properly.

Along with slow growth, heat attracts pests and diseases. For example, spider mites and powdery mildew tend to thrive in warm conditions. Additionally, when it gets very hot, water evaporates faster from the ground where the cannabis plants are growing.

Therefore, plants not only require frequent watering, but they may have problems absorbing fertilizers and nutritional supplements due to drying out of the soil or substrate (hydroponics). This results in chemical burns that can damage the roots, stem and leaves.

Temperatures that are too high for autoflowers, combined with high air humidity, lead to a number of other problems. Plants growing in hot, humid conditions without adequate air circulation may develop bud rot or mildew. This puts a lot of stress on the cannabis and actually destroys the buds that the grower has worked hard to develop all season.

What happens when temperatures are too low?

Cold temperatures are just as harmful to cannabis as excessively hot ones. However, compared to heat, cold can stress plants or even kill them completely.

It is generally accepted that the minimum temperature for marijuana is 15°C, below which it cannot be grown. She will have growth problems and die.

It should be remembered that low temperatures can also reduce a plant’s ability to photosynthesize, just like very high ones. The enzymes that are responsible for the light-dependent reactions of this process are not as active at low temperatures, so cannabis bushes grow more slowly.

In addition, the cold helps create ideal conditions for the development of mold. Many species prefer cold, moist environments and can form on roots, leaves and buds when temperatures drop below acceptable levels.

It is worth adding that most marijuana strains like slightly cool temperatures at night (about 18°C). Some strains develop wonderful purple or blue hues when grown in cold temperatures. This produces great looking buds at harvest time.

However, the ability of cannabis to impart a purple or blue hue to buds depends largely on genetics. This is most common in indica-dominant plants found in mountainous regions such as the Hindu Kush (Central Asia).

How to create the ideal temperature for cannabis?

Growers agree that the ideal temperature for marijuana is around 25°C. Such conditions can be created with the help of a growbox - a device in the form of a folding tent or a closed box-cabin, which is placed not in the open air, like a greenhouse, but indoors. If you're starting new marijuana plants, you may want to play around with the temperature a little and see how they react.

You can buy a high-quality growbox on the official website of the Coffeeshop online store. The devices have different dimensions. Their inner walls are covered with a special material that effectively reflects light when using artificial lighting. All products have a ventilation window for blowing plants.

*However, we remind you that germinating marijuana seeds on the territory of Ukraine is prohibited and is punishable by law, please follow the laws of the country in which you are located. The information is for scientific informational purposes only.