How to Grow Cannabis in a Greenhouse: A Guide
Growing cannabis in a greenhouse is an effective cultivation method that combines the perks of outdoor growing with those of indoor cultivation. Learn all about it below!
Learn to grow cannabis in a greenhouse.
Growing cannabis in a greenhouse is ideal because it combines the benefits of outdoor growing with those of indoor cultivation. In this guide, we’ll show you how to do it, offering tips and advice as we go along. If you don’t have a greenhouse yet, and want to build one, we can show you how to do that, too.
WHY GROW CANNABIS IN A GREENHOUSE?
Maybe you’re wondering why you’d want to grow weed in a greenhouse, as opposed to growing indoors in a tent or having an ordinary outdoor grow in your garden. Let’s look at the advantages of greenhouse cultivation over other growing methods.
YOU CAN EXTEND YOUR GROWING CYCLE
You can extend the cultivation period into the fall and winter seasons simply by adding more light during cloudy days, and progressively keeping them on longer to compensate for shorter daylight hours. Likewise, if you want to start a new grow before the end of winter, you can add a low-powered light to supplement natural daylight.
PROVIDES THE IDEAL MICROCLIMATE FOR GROWING CANNABIS
A greenhouse environment can sustain higher average temperatures than chilly open fields or gardens. Plus, during cold or hot seasons, you can heat or cool a greenhouse if needed. Even without a heater or cooling system, a greenhouse will provide a more consistent range of maximum and minimum temperatures, without the extremely dry and hot conditions typical for indoor grow rooms. A more consistent microclimate means healthier plants and bigger harvests.
ALLOWS FOR YEAR-ROUND CULTIVATION
The climate within greenhouses can easily be controlled, for instance by opening windows or installing fans. And, since the walls of a greenhouse keep humidity and heat inside, it allows for year-round cultivation. This control over climate and exposure to light isn’t possible in regular outdoor cultivation.
MORE CONSISTENT HARVESTS
Greenhouse harvests tend to be more consistent over time, both in quantity and quality. This is also why the majority of commercial medicinal cannabis produced today is grown in greenhouses.
MORE ENERGY-EFFICIENT THAN INDOOR GROWING
Since cultivators can take advantage of natural sunlight, growing in a greenhouse is way more energy efficient. You will also have much lower electricity costs compared to growing in a room or tent.
PROVIDES PROTECTION FROM THE ELEMENTS
Unlike outdoor cultivation, a greenhouse protects your plants from the elements. There is no threat of rainfall or storms harming your precious ladies. In addition, a greenhouse prevents scavenger animals from having their way with your crops.
KEEPS PLANTS SAFE FROM DETECTION
A greenhouse allows for discreet growing with a greatly decreased risk of detection. Your plants will be safe and secure, so you can go to sleep without worrying about thieves and vandals.
IT’S NOT EXPENSIVE
Growers don’t need to spend a lot of money to set up a greenhouse. A simple walk-in greenhouse can be purchased for little money, and will do a decent job of housing your plants. Building a DIY greenhouse is another inexpensive option. For a simple grow using natural light and hand-watering, there’s no need for expensive grow equipment.
HOW TO GROW WEED IN A GREENHOUSE?
Growing cannabis in general involves many variables that need to be kept in check. Growing in a greenhouse is no exception. However, differences in methodology from indoor and outdoor cultivation need to be taken into account. Here is a list of steps you can take to run a successful greenhouse grow.
PICK A SUITABLE STRAIN
Cannabis strains differ in how they grow, and in regards to their requirements. The best type of cannabis for your greenhouse setup ultimately depends on a number of factors, including your local climate, available space, and whether you’re planning to use an artificial grow light. Let’s dig in a little deeper:
Autoflowering cannabis is optimal if you’re growing using natural sunlight. As autoflowers don’t require a set light schedule to veg and flower, variations in sun exposure won’t harm your plants or diminish yields as much as photo-feminized plants. This also means you can plant and harvest autos in your greenhouse at any time of year—as long as you support ideal environmental conditions.
Lastly, the smaller size of most autoflowering varieties comes in handy if space is constrained, which is usually the case with small greenhouse setups. To make up for lower yields from smaller plants, you can simply grow more of them in your available space (e.g. the sea of green method).
Growing photoperiod feminized cannabis is also possible in a greenhouse, but comes with some constraints, especially if you’re using exclusively natural light. As these strains flower based on the hours of light they receive, you rely on the seasons to support vegetation and stimulate flowering.
However, you could also set up an artificial grow light on a timer to control your plant’s development. But then you may also need to look into making your greenhouse light-proof. Otherwise, the natural daylight could interfere with your artificial light schedule, causing its own issues.
Another issue when growing photo-feminized plants in a greenhouse is that you may need to train and prune your ladies to prevent them from growing out of contol. Especially if you’re using only sunlight, plants can get tall and spindly, and may require some topping, scrogging, and the like to remain at a reasonable height.
PLAN YOUR GROW WINDOW
With natural light as the main source of energy in your greenhouse, you need to plan your grow window accordingly. Ideally, you want to be ready as soon as daylight hours (and temperatures) start increasing in spring.
Even though your greenhouse will maintain higher temperatures than those outdoors, you should wait until there is no risk of frost before bringing your plants into the structure. Depending on your location and local climate, this may be early or quite late in spring.
Building on the above, you can always germinate your seeds indoors and start nurturing your plants with low-powered CFLs to give them a head start. You won’t need much space for this, and CFLs tend to run cheap. This way, even if the rest of your grow is conducted using sunlight, you can still take full advantage of the outdoor growing season.
MOVE SEEDLINGS TO THE GREENHOUSE GRADUALLY
As soon as your plants get a little bigger and stronger, after about a week or two, you can gradually get them used to their new growing environment. Go easy on them, and don’t move them abruptly from the cosy indoors to the greenhouse. Set them in the structure for just a couple of hours each day and increase over the first few weeks.
This way, stress is reduced and plants can continue to develop without a hitch. Your plants are sensitive, especially at this stage, so don’t use your greenhouse as an excuse to be negligent.
SUPPLEMENT LIGHTING ACCORDING TO WEATHER
One of the great things about greenhouses is that they allow growers to supplement natural lighting with an extra grow light. Stretches of poor/cloudy weather can be overcome without fear of a diminished harvest, and your electricity bill will be vastly lower than if you grow indoors.
Then again, if one is growing in a suitable climate with plenty of sun, a supplemental light may not be necessary. Still, having one at the ready is never a bad thing for a cannabis grower.
USE BLINDS OR COVERS TO FORCE FLOWERING
A greenhouse makes it possible to force-flower cannabis using light deprivation techniques. Elaborate timed shutters could be installed to obscure plants for this purpose, but simple blackout covers or blinds can also do the trick—at a fraction of the price and with much less effort.
In addition to allowing you to flower your weed at any time, blackout covers also serve to prevent cannabis light pollution (e.g. nearby street lighting), which could otherwise interfere with flowering for photo-feminized plants.
PRO TIPS FOR GROWING CANNABIS IN A GREENHOUSE
You want your cannabis to be happy, comfortable, and productive in your greenhouse grow-op. So, what else do you need to know to achieve a great harvest? Check out our pro tips below.
In this article, we cover how to successfully grow cannabis in a greenhouse. Learn the pros of greenhouse weed cultivation and get your own grow started today!
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.