For anyone starting their journey in the cannabis-growing world, there are a lot of things to learn. But what if you want to get into growing weed in a greenhouse? In this article, we’ll go over some of the basics for setting up a marijuana greenhouse and some of the pros and cons for beginners.
Is there anything more gratifying than starting a garden from seed? Waiting for those first sprouts is like the eager anticipation of Christmas morning when you were younger. With proper care and attention, your plants will flourish and provide an abundance of whatever it is you’re growing. Whether you want to grow tomatoes or marijuana, we can offer suggestions on what works best in a greenhouse as well as detailed instructions on how to achieve optimal growth conditions specific to your chosen crop.
What is a Greenhouse?
A greenhouse is a sturdy outdoor frame with a clear plastic covering, designed to grow fruits and vegetables, herbs, plants—and marijuana.
Most people opt for a greenhouse because it’s easier to manage the conditions inside. Greenhouse weed often flourishes better and quicker than outdoors, due in part to the lack of exposure to harsh weather conditions, higher levels of carbon dioxide, and more stable temperatures.
Greenhouses are crafted from numerous materials, take different shapes and come in diverse sizes. If you’re looking for a small home grow solution on a budget, for example, you can make a hoop house out of PVC pipes and painter’s plastic. However, if your space and budget permit it, you could opt for an industrial greenhouse with automated ventilation & temperature controls and large fan installations instead.
The form of your greenhouse can be gothic, A-frame, dome, tunnel, lean-to, gable, flat-arch…etc. to suit your horticultural needs and the amount of space you have available. No matter where you put your greenhouse though; make sure it is in a location that gets at least six hours of sunlight every day.
What to Grow in a Greenhouse
A greenhouse is a versatile way to grow plants. You can use pots, raised beds, hanging planters, and trellises indoors all year-round regardless of the outdoor conditions. Greenhouses are also suitable for starts that will ultimately grow outdoors in the summer months.
Greenhouses provide an optimal environment for flowers because they mimic the heat and humidity of naturally sunny days. Crops that favor cold weather, such as lettuce, broccoli, and peas also do well in greenhouses. In the summer months, you’ll notice tomatoes, squash, and cucumbers bloom rapidly inside a greenhouse. However, unless you have open-door access for pollinators to come inside , be sure to hand pollinate your plants .
More and more people are finding success in growing cannabis in greenhouses. Growing cannabis in a greenhouse environment allows growers to take advantage of the sun’s power, while also having protection and control over their plants.
How Many Cannabis Plants Can You Grow in a Greenhouse?
The number of marijuana plants you’re allowed to grow per household differs by state in the U.S. For example, in Oregon, each household can cultivate up to four recreational plants if they have a medical marijuana card. If not, then they are only allowed to grow six plants total per patient per household. It’s important to be mindful of these numbers as well as the growing requirements since they vary from place to place.
If you want your marijuana plants to grow big and strong, then you’ll need more than just high-quality fertilizer. You’ll also need to give them the proper amount of space, sunlight, and water. Follow these steps and you can expect a bountiful harvest come harvesting time.
Pots are typically best to use inside a marijuana greenhouse so you can relocate them if necessary. If you choose this option, allow for at least an 8×8 foot area per plant once it’s in its final pot. Adequate airflow is crucial for your plants, and omitting this key element will make it difficult to work around overcrowded plants.
Mature plants need a final pot that is, on average, 65 gallons. growers in California and Oregon have to go even bigger, 100 or 200-gallon pots.
Can You Grow Weed in a Greenhouse Year-Round?
No matter your location, you can grow weed year-round in a greenhouse. Most greenhouses are equipped to handle any climate, but if you live somewhere with cold winters, you can still use a greenhouse as long as it has heating elements. In addition to heaters, though, you will need additional lighting since days are shorter in winter months. These lights don’t produce enough heat to stop frost damage entirely, but they lessens the chances of harm somewhat.
If you choose an A-frame or gothic style structure for your greenhouse, you will be helping to prevent damage that can be caused by the weight of snowfall on top of it.
Items Needed to Start a Greenhouse Grow
The following items are necessary to start a greenhouse cannabis grow, in addition to seeds or starts:
- Greenhouse framing materials
- Durable covering
- Fans / ventilation
- Smart pots or something similar
- Soil or growing medium of choice
- High-quality nutrients
- Water reservoir and access to plenty of fresh water
- pH meters and adjusters
- Trellis materials
To get the most weed possible, you might want to look into a light deprivation system. Light dep can help you grow more than one crop per year.
How Much Does it Cost to Start a Greenhouse
It is difficult to price a greenhouse until you understand how large it has to be. A standard DIY greenhouse, made with aluminum framing and one layer of polyethylene (PE) plastic costs approximately $15-20 per square foot. This does not include the cost of lights, heat or other materials necessary for growth. If you want a custom greenhouse complete with fancy features (like an automated light dep system), plan on spending around $35-40 per square foot.
If you’re familiar with construction and looking to save money by repurposing materials, you can build a 1,000 square foot greenhouse with a light dep system for around $10,000.
While it may be tempting to jump right into starting your greenhouse grow, there are plenty of costs to consider first. You’ll need materials for each plant, and depending on the type of plants you want to grow, you may need specialized lighting or heating equipment. Don’t forget to factor in the cost of these items before getting started.
Pros & Cons to Growing Weed in a Greenhouse
Be sure to consider the advantages and disadvantages before deciding if a greenhouse is the right fit for you.
- Extended growing cycle and option to grow year-round
- Protection from the elements (including deer, rabbits, rodents, etc.)
- Control over a microclimate to dial in ideal plant needs
- Consistent harvests year over year
- More environmentally-friendly (and cheaper!) than growing indoors
- Depending on climate, energy costs may stack up if heating/lighting during the winter
- Odor or aesthetic may be unpleasing to neighbors
- Can easily take up a large amount of space that may have been useful for other things
- Can be expensive to build depending on the materials
- Requires more attention than an outdoor grow to ensure it’s running smoothly
Before you start building your greenhouse, take some time to research how big your plants might be when they’re fully grown. That way, you won’t have to worry about whether or not you guessed the right size. If you want to grow more than one type of plant, leave room for a few tomatoes or cucumbers so that you can enjoy fresh produce all summer long!
Best Strains to Grow in a Greenhouse
These are the best strains of cannabis to grow in a greenhouse: cauliflower and photoperiod feminized. Autoflowering cannabis automatically switches stages from vegetative growth to flowering, so you don’t need to be concerned about light schedules. This then eliminates the necessity for a light dep system. Some great examples of these strains include Purple Punch, Strawberry Banana, Frisian Dew, Wedding Glue, Northern Lights, and White Widow.
Apart from autoflowering feminized seeds, photoperiod feminized seeds are another great way to grow in a greenhouse. That being said, they will grow better with a light dep setup. These strains will flower as the days get shorter and we move from late summer into early fall. Some of the heaviest yielding greenhouse strains include Blue Dream, Sour Diesel, Super Silver Haze, Critical Kush, and Skunk XL.
Is Greenhouse Growing Right for Me?
If you are still unsure if it’s the right choice for you, ask yourself the following questions:
- Do I have the time and money to build and operate a greenhouse?
- Do I have the space to accommodate my plans?
- Does this location have easy, unlimited access to fresh water?
Starting up a cannabis greenhouse is time-consuming, but it comes with many benefits. Not only will you learn more about cultivations, but –with proper care–you can also end up harvesting some great buds.