How Cold Is Too Cold?

This winter has been intense here in the United States. When I say intense I mean COLD.

As a grower there are several key factors to keep track of to keep your plants alive and healthy. The main 5 are light, temperature, food, air, and water. In this episode we are going to focus on the temperature.

As everyone is gearing up for another light dep season or long season I figured we should talk about what is actually occurring right now and affecting your grows. You know, the cold weather.

In fact I’m really only going to talk about the low end of the temperature spectrum. I’m going to break the low end of the temperature spectrum into two categories. The first category will focus on the minimum temperature to keep your plants thriving. And the second category will focus on the minimum temperature to keep your plants alive.

These two temperatures are definitely not the same!

Plants cannot produce heat like animals. They strictly rely on their environment for their temperature. This means when it’s hot out, the plants get hot and when it’s cold out the plants get cold. And we all know that when it’s cold out that plants don’t grow very well and if it gets too cold they can even die.

For the purpose of this article there are some basic assumptions that I am making.

Assumption 1: These minimum temperatures occur during the coldest times of the night cycle and it never gets colder than this during the day.

Assumption 2: The temperature during the day gets at least 10 degrees Fahrenheit warmer.

Category 1: Minimum Temperature to Keep Your Plants Thriving

The lowest temperature you really want your plants to get to is 60 degrees Fahrenheit. Any lower than that and you risk slowing your plants growth rate down. This is because critical growing processes can’t occur when the plant gets too cold. And if that low temperature occurs in the soil where the plant gets it’s food and water from that will really slooooow your growing down.


Category 2: Minimum Temperature to Keep Your Plants Alive

The lowest you want your plants to get to is between 40-45 degrees Fahrenheit. The range is there because some varieties (indica dominant) can handle the cold much better than other (sativa dominant) strains.

Ideally you want to keep your plants minimum temperatures much higher than this but you may not have the resources to do so. You may be growing at a higher elevation, or growing off-grid or you may not have a greenhouse. So you make do with what you got.

As I tell my daughter you get what you get and you don’t throw a fit!

I hope this helps you during this cold winter season.