Growing your cannabis seeds in a greenhouse can be quite a bit different then growing cannabis indoors or outdoors. Growing in a greenhouse starts with picking the right cannabis seeds to get the best growth for your plants and buds. In this article we will discuss how to grow the best cannabis plants in a greenhouse and some cannabis seeds that we recommend, for the best results when growing your cannabis this way.
Growing cannabis seeds in a greenhouse comes with some benefits as well as some issues that we will review.



What is a Greenhouse?
A cannabis greenhouse is a structure that is semi indoors, however it is made to use sunlight instead of electrical lighting for plant growth. There are hybrids that use artificial lighting and sun lighting for cannabis plant growth. The structures can be very small, and only hold a few plants or very large and hold thousands or even tens of thousands of cannabis plants in them. They trap the heat inside of them on cold days, and on warmer days will vent the heat to the outdoors. This typically happens in the summertime.
Greenhouses are great for growing cannabis in cooler climates as they are provided free heating from the sun. The sun heats up the inside of the greenhouse, promoting faster growth of plants, even when it is cooler outdoors.
Is a Greenhouse Considered Indoor Growing?
While growing cannabis in a greenhouse has a few things in common with growing cannabis directly indoors it is typically not considered the same as growing cannabis indoors. When growing indoors growers generally have more control over the growing environment then growing in a greenhouse environment. Another difference is that in a greenhouse you will generally have higher ceilings, and a much larger space to grow your plants.
As some types of cannabis will grow better in a cannabis greenhouse environment then indoors or even outdoors depending on the cultivar that is being grown. Sativa strains tend to do very well in greenhouses as they have a longer growing season and also grow better than indicas in hotter climates.
Greenhouses are a very good middle ground between growing completely outdoors, and indoors.
Setting Up a Cannabis Greenhouse for Best Results
There are many types and styles of greenhouse out there. Some greenhouses use wooden frames and some use plastic or metal. The materials that are used to cover the greenhouse can also vary. Most growers use heavy duty plastics to cover their greenhouse, however you can also use fiberglass, glass, or anything else that will allow for sunlight to get in while keeping heat in.
Most cannabis greenhouses consist of a frame covered in plastic, they can be any size, but bigger is better when growing cannabis plants unless you intend to trim them. Growers can use pots in a greenhouse, hydroponics or grow directly in the soil. If you need more information about growing in soils for cannabis we recommend this article.
Your cannabis greenhouse seeds should be planted beforehand in pots in your greenhouse first. This way you can transplant them directly into the ground or in bigger pots at a later date. Make sure your cannabis greenhouse is also built in a spot that will allow for at least eight to 10 hours of direct sunlight.
Any good greenhouse will also need to have a good ventilation system, consisting of a large vent fan to keep the greenhouse cold in the hotter summer months. Depending on the size of your greenhouse you will need a larger or smaller fan. It is also a very good idea to have air circulation fans inside the greenhouse to move air over and around the plants.



Buying a Cannabis Greenhouse vs Making your own
One option for getting a greenhouse is to buy one from a manufacturer. Cannabis growers can buy them in all shapes and sizes to suit their needs. We never recommend buying cheap ones on amazon as the plastic that they use breaks down very quickly over the years leaving you with nothing but the frame after a few years. They are also made with very flimsy supports that will either blow away, or bend and break over time.
If you are more of the DIY type of person it is typically pretty easy to build your own frame and cover it with plastics. Using PVC piping works very well for making your own greenhouse frames as it can bend easily, and be cut as needed for your framing.



Dealing with Greenhouse in the Wind
Greenhouses are very susceptible to stronger wind damage. If you are going to grow or build a greenhouse to grow cannabis seeds we recommend taking into consideration the wind in your area. If you are using something like plastic to cover your greenhouse, use a very strong type if it is windy in the area you live. As your cannabis greenhouse frame can be very light as well as the covering, wind can sometimes pick up your greenhouse and send it miles down the road.
Make sure that you have strong support to hold your cannabis greenhouse in place. Some growers will remove the plastic covering after their harvest of cannabis is finished. This is very useful if you live in a windy part of the world.
If you make your cannabis greenhouse out of glass or fiberglass this will be less of an issue.



Benefits of Growing inside a Cannabis Greenhouse
Once the grower has set up their cannabis greenhouse, there are many great benefits for using one.
First comes if you live in a region of the world where there are shorter or shorter cannabis growing seasons, having a cannabis greenhouse can easily extend your growing season both in the spring and in the fall by up to a month. Growing this way could give you up to a whole month of extra growing time under the free energy of the sun.
As a grower you can put your seeding in your greenhouse sooner and leave them in to finish before harvest, giving you bigger and larger, more mature cannabis harvests. The greenhouse will also be warmer during these times to help the plant grow much faster then if it was outdoors.
Another understated benefit of growing in a greenhouse is that natural sunlight can improve terpene and cannabinoid content in your harvested cannabis buds. Many growers prefer this fuller terpene profile that comes with growing cannabis in a greenhouse setting.
Growing in a cannabis greenhouse is also very cost effective due to the fact that the grower does not have to pay for energy for lighting costs which can be one of the most expensive things when growing cannabis directly indoors.
Cannabis Greenhouses can Protect your Crops from Pests and Animals
Growing directly outdoors can come with many unwanted pests and animals that can and will come for your plants. I think there is nothing worse than visiting your outdoor plants and finding that something has dug them up, eaten them, or they are covered in pests like spider mites.
Greenhouse growing reduces the chances of this happening to your cannabis crop. While the plants are not grown directly outdoors, they are protected from many of these issues. The plants are getting the full benefit of growing in the sun while not having to worry about the deer eating them.
Greenhouse Growing Protects your cannabis plants from the elements
Growing Cannabis in a greenhouse can also protect your plants from strong outdoor summer storms. While not completely indoors, a greenhouse can protect your plants from heavy rains, and wind damage. Greenhouse cannabis plants generally don’t need as much support as plants grown directly outside.
Disadvantages of a Cannabis Greenhouse
While there are many advantages of growing cannabis in a greenhouse environment there are also some drawbacks that growers will need to consider.
First and foremost is that, building, or buying a greenhouse can cost a considerable amount of money over growing your plants directly outdoors. Some pre-made greenhouses can cost tens of thousands of dollars. Even a homemade greenhouse can have costs that can add up quickly depending on the building materials, and equipment that is being used. These upfront costs can be a major drawback for using a greenhouse to grow your cannabis.
Now that your plants will not be getting natural rain will also require that you have to either set up a watering system or haul water and hand water plants. This can also add to greenhouse costs such as water and electrical costs.
Cannabis Bud Rot and Molds can be more of an issue in a Greenhouse
Molds and bud rot can quickly ruin crops before harvest, especially outdoors. This can be even more true growing inside a greenhouse. Because a greenhouse is warmer it will also come with higher humidity and this can be bad for late flowering cannabis crops.
Growers will need to control this humidity well to avoid these issues in the environment with excellent air exchange. It is also a very good idea to keep a very close eye on your buds the closer you are to harvest. If you can catch the bud rot before it gets out of control you can stop it or even prevent it from happening. If you would like to learn more about bud rot and mold when growing cannabis we recommend this article.



Greenhouse vs Indoor Potency for Cannabis
While much of the potency of cannabis depends on the plant’s genetics, growing plants under natural sunlight will result in higher potency cannabis. This is also true when growing cannabis plants in greenhouses.If you are interested in learning how to grow cannabis indoors please see our guide for this here.
Our Best Cannabis Seeds for Greenhouse Growing
This list of seeds are ones that we recommend to you for growing cannabis in a greenhouse. These seeds will also grow well outdoors. If you are looking for cannabis seeds to grow in a greenhouse environment these seeds do very well under natural sunlight.
Final Thoughts
If you are interested in growing cannabis outdoors with some of the benefits that come with growing cannabis indoors than growing in a cannabis greenhouse is a great option. These methods of growing cannabis come with good control over your environment while at the same time costing less money to grow using the sun.