greenhouse cannabis growing guide

Growing Marijuana in a Greenhouse: What Are the Benefits?

Greenhouses are a great, inexpensive way to cultivate cannabis. They harness the power of the sun, provide a warm climate, and protect gardens from harsh environmental conditions.

They also allow for year-round cultivation, climate control, and a controlled exposure to sunlight. What’s more, they’re cheaper than growing indoors and produce a more consistent product than fully outdoor grows.

How Does a Greenhouse Work?

Solar radiation (energy from the sun) passes through the transparent walls of a greenhouse and heats up soil and plants, keeping a greenhouse warm even when the outside air temperature is cold.

In turn, soil and plants release energy as infrared radiation, which can’t escape the greenhouse, so the trapped heat warms the air.

On a hot day, you experience the science behind a greenhouse when getting into a parked car that has been left in the sun.

This greenhouse effect opens up the door to year-round cultivation, but cannabis still needs light from the sun in addition to the warmth that a greenhouse provides.

Recreating the Cannabis Life Cycle

Cannabis generally goes in the ground outside between April and July, when the sun is out for most of the day. This keeps plants in the vegetative stage.

Once cannabis starts getting 12 hours of light or less, it’ll start flowering and producing buds. This happens outdoors at the end of summer, when days start to get shorter.

Advanced greenhouses can allow you to grow year-round by controlling light. They can provide supplemental lighting when it’s too dark outside and they can block out all incoming light if it’s too light outside.

Advantages of Growing Greenhouse Cannabis

Lighting Control

Supplemental lighting allows the grower to extend the hours of daylight and to improve the quality of light on overcast days. This will give you more control over the vegetative state of your plants.

Weather and Climate Control

Controlling your greenhouse climate is essential to producing a quality product. Some greenhouses have windows or paneling that can be opened or removed to either allow for wind circulation and to cool plants, or to trap in heat.

Greenhouses also provide cover for your plants, as heavy rains will damaged them and cause them to rot if too much moisture is trapped inside the buds. Some can also have dehumidifiers, heaters, air conditioners, and fans, all of which will also regulate the climate.

Manipulating Life Cycles

A common practice among greenhouse farmers is to run cycles of plants known as “light deps”—short for “light deprivation”—during the summer season. By cutting off the amount of light a cannabis plant gets before the end of the season, you can trick it into flowering early. This will allow you to pull a crop early, which is key if you live in a climate that gets cold and wet early in the fall—you’ll want to harvest before the rain sets in and causes your buds to get moldy.

If you want to continue growing cannabis through the fall and winter, you will have to lean more heavily on supplemental lighting and heaters.

During the winter solstice in Seattle, for example, there’s less than nine hours of daylight, and the light that is available is low in the sky and poor for growing. This light and energy will still help heat the greenhouse, but you would need to use supplemental lighting to extend the hours of light in the day in order to get a quality product.

Energy Conservation

The ability to control light and keep the climate stable will allow for year-round cultivation just like indoor growing. But growing outdoors and with a greenhouse is a lot more inexpensive than growing indoors, and you’ll save a lot of money on electricity costs. Even if you need to supplement light in a greenhouse, it’ll still be cheaper than the energy needed to power an indoor operation.

Greenhouses are becoming the most popular way to cultivate cannabis, as they allow for year-round cultivation, climate control, and controlled exposure to sunlight.

Tips for Growing the Best Pot in Your DIY Greenhouse

Saturday August 6, 2016

T hough it certainly is nice to be able to visit a dispensary for the perfect strains of bud, growing your own marijuana is so much more rewarding. Not only can it save some serious cash (especially if you smoke as much as I do), but it helps settle concern regarding cultivation practices (you know exactly what fertilizers and pesticides have been used to grow the herb) and helps you gain a true appreciation for the time and effort involved in cultivating cannabis. Growing your own cannabis can also be a great way to experiment with cross-breeding, too!

But, growing your own marijuana is not the same as popping a tomato plant into the ground. In order for a cannabis crop to produce a large, high-quality harvest, it requires proper fertilization, diligent pest control, the right balance of heat and humidity, and a very precise lighting schedule. Creating the ideal environment indoors is a popular option but may require a large investment of both time and money, and growing outdoors only allows for a single harvest each year and includes the disadvantage of a potentially insecure grow area.

Greenhouses combine the benefits of both indoor and outdoor grow areas by expanding the grow season, utilizing solar power whenever possible, securing the grow area from pests and intruders and shielding the grow area from the view of passers-by. However, the strict photoperiod of many cannabis strains (except for autoflowering strains) and other crop requirements means that ganja greenhouses have to include a few important features.

Things to Remember When Growing Cannabis in a Greenhouse

  • Year-round cultivation may require supplemental lighting and black-out screens: In order for cannabis to grow, it needs a precise light cycle: 16 – 18 hours of light during the veg stage and 12 hours of light (only) during the flowering cycle. Transitioning from a veg to flower light cycle happens naturally outdoors as the seasons transition to autumn but can be mimicked with the use of black-out screens (or even a tarp thrown over the enclosure at the correct time every day). Likewise, when trying to grow plants larger during the veg stage, supplemental lighting may be needed during short winter days.
  • Greenhouses can get HOT: To keep your girls growing strong, it is important to keep them as comfortable as possible. Unfortunately, greenhouses tend to trap heat making the plants much more susceptible to heat stress during warm summer months. This can be remedied through intake and exhaust fans to help maintain an ideal temperature of around 70 to 80 degrees Fahrenheit.
  • Off-grid solar kits can help maintain an ideal environment: The sun can (and should) be used for more than photosynthesis. To help control the cost of year-round greenhouse maintenance, off-grid solar kits can be a great investment. Use them to power ventilation and humidity controllers, supplemental lighting or just some good ol’ tunes to help keep you (and your plants) happy.
  • Greenhouses are most effective when they are secure: To grow personal cannabis, the grow area should always be secured from intruders or young people which can be accomplished with the addition of a simple lock on the enclosure or surrounding fence. But greenhouses should also be secured from pests and invasive plants as well. This can be accomplished with the use of bug screens on doorways, and fabric weed barriers lining the greenhouse floor.

DIY Greenhouse for Your Cannabis Grow

You can create your own cannabis greenhouse relatively easily without having to invest a ton of money in a professionally-build enclosure. To learn the basics of creating your own DIY greenhouse, check out this video by Jorge Cervantes, self-appointed ganja guru and author of numerous cannabis cultivation reference guides.

Growing pot in a DIY Greenhouse gives you the best of both worlds, combining the benefits of both indoor and outdoor grows. Learn how to produce a high-quality harvest using these tips.