Cannabis is a very temperature-sensitive plant. Growing cannabis year-round in areas with seasonal temperature changes requires an indoor operation. There are also additional considerations for growers who intend to maintain an active crop throughout the year.
Choosing Cannabis Seeds
- There are many strains of cannabis seeds from which to choose. Deciding what your main objective is will narrow the choice down. If you are growing cannabis for medical benefits, select strains with CBD (cannabidiol is the second most prevalent active ingredient in cannabis and can have no more than 0.3 percent THC to be legal at the federal level) compounds? Suppose you are growing cannabis for recreational products. In that case, you want seeds with high THC (a crystalline compound that is the main active ingredient of cannabis in which users get "high sensations") compounds.
- When growing cannabis in colder temperature areas, consider what seeds/strains do best in colder temperatures. Most plants, in general, can't survive long when grown in colder temperatures outdoors. Ideal temperatures for cannabis are between 72-86˚F (22-30˚C). The lowest possible temperatures you should expose cannabis plants to is 59˚F (15˚C). Anything below that will likely kill it, and the lowest acceptable temperatures can stunt their growth.
- Ten cannabis strains that do well in colder temperatures are Afghan Kush, Blue Cheese, Critical, Skunk XL, Northern Lights, Royal Moby, Shining Silver Haze, Somango XL, Special Queen I, and White Widow. Many other strains do well in colder temperatures; these are just a few to give you an example.
Why use cannabis strains that thrive in cooler temps during the winter or in colder climates?
Growing cannabis all year long can be a challenge. Cannabis may be a "weed," but it is very particular to temperatures and light. Investing in cannabis strains that thrive in colder temperatures increases the grower's profit margin by not running the heat as high as other cannabis strains.
How does lighting affect cannabis in colder temperatures?
If you are growing in a greenhouse and utilizing natural light, you will need to supplement with artificial lighting. When colder temperatures/seasons come, it usually brings with it a decrease in daily natural sunlight.
Lighting is essential to cannabis in all stages of life. Imitating the natural spectrum of sunlight is very important whether growing in a greenhouse or indoors. LED grow lights emit the full spectrum of light for plants, thus emulating natural sunlight.
Full-spectrum LED grow lights can be controlled to emit more or less of one color in the spectrum than another. Managing the light spectrum, the height of which the fixtures are suspended above the canopy, and the length of time the lights stay on will contribute to healthy plants and a good harvest.
Energy-efficient LED grow lights lower overhead costs and provide different wavelengths that improve plant growth during all development stages. Red wavelength light is helpful for plants who need help with flowering and fruiting, while blue wavelength is necessary for foliage growth.
Is supplemental heating needed for growing cannabis in colder temperatures?
Yes, supplemental heating is necessary for growing cannabis in colder temperatures. Whether you are in a greenhouse or indoors, you will need heat sources and fans. Heat sources usually are not enough to circulate the heat around your enclosure to make it more evenly temperate. Placing fans in various areas to move the heat around will make the climate inside your growing facility more consistent, and it will help eliminate extra humidity and cold.
Having thermostats (that automatically control the heat and fans) in several places in your growing rooms to monitor temperatures will ensure that the plants won't freeze. Because plants are full of water and other fluids, freezing becomes deadly. Water quickly expands when ice crystals form, rupturing within the plants' cells.