Growing weed in a greenhouse: this is what you need to know!

Growing weed in a greenhouse: this is what you need to know!

Want to grow weed in a greenhouse instead of indoors? Check this blog and read everything you need to know about a greenhouse weed cultivation. Last updated 06/12/2022

    Many weed cultivators use greenhouses for their plants. But why are they so popular? This article about growing weed in a greenhouse will investigate the many benefits of greenhouses and answer some of the questions you may have when considering which setting is best for your personal situation.

    What is a greenhouse and how does a greenhouse work?

    A greenhouse is an outside structure consisting of a metal frame and numerous glass panels. It creates an artificial microcosm climate in which plants can thrive, even when the weather is harsh and cold outside.

    Greenhouses work by utilising a simple scientific principle known as ‘the greenhouse effect’. As light passes through a transparent material (glass in this case) and meets an opaque surface (plants, anything inside the greenhouse), some of the light energy is transformed into heat.

    The darker the opaque surface, the more heat it will absorb. Greenhouse panels are highly effective at transmitting light but not heat so most of the heat remains inside the greenhouse where it will benefit the plants inside.

    The advantages of growing cannabis in a greenhouse

    Greenhouse cannabis cultivation is becoming more and more popular as it combines the benefits of indoor and outdoor cultivation. It is a simple and inexpensive method, after the initial set-up costs, since the facilities required for indoor cultivation are not necessary, as well as making the most of the free sunlight as in a garden plantation. At the same time, it has the advantage of sheltering outdoor plants from the vagaries of the weather. The simplicity of its equipment and the discretion it provides are the reasons for the resounding success of the humble greenhouse. Yet, there is more:

    1. Growing outdoors with the benefits from indoors
    2. Extending the growing season
    3. Cheaper compared to indoors

    1. Growing with the benefits from indoors

    A greenhouse makes it possible to grow outdoors, with all the advantages that this implies, such as controlling growth phases and ensuring rats, birds and deer are not able to destroy the crop. In the beginning, you might feel that the assembly seems tedious or that it represents a significant investment. Still, nothing is further from reality: this installation can be simple or sophisticated, it depends on what you want.

    The greenhouse mixes the positive and natural elements of outdoor cultivation with protection from less desirable features. The higher degree of control is particularly appreciated in the northern regions, where growers are more exposed to cold and lack of light. In the southern Mediterranean, for example, the climate should facilitate cultivation throughout the year, without hardly any need for intervention. 

    2. Extending the growing season and controlling phases of culture

    Probably the most powerful feature of a crop of this type is the ability to control the climate and cycles and thus obtain several crops per year, vastly increasing yields. These types of intervention are not possible with outdoor plants, which are at the mercy of temperature and season changes. Greenhouses allow you to limit the exposure of cannabis to the sun and so deceive into flowering earlier. Indoor growers perform this trick with expensive artificial lighting.

    There is another good reason to start the growing period earlier: to extend the plant’s growing phase. The longer it is, the more abundant the plants and the more intense their flowering. And as a reward, the final harvest will be much better. For this phase to be a success, it is essential not to allow too much cold the first nights, by using the heaters when necessary.

    Thanks to the greenhouse, it is possible to harvest in early August, replant and harvest again in autumn. The artificial environment created manages to retain heat, so growers can start planting cannabis a little earlier than outdoors.

    The use of heating devices allows the cultivation to continue even when the cold arrives. Then, in summer, when the high temperatures come, ventilation systems can be deployed to keep the plants in good condition. Ventilation and humidity control is an integral part of cannabis greenhouse management to prevent the plants from succumbing to mould, milder and diseases. To be able to photosynthesise, the grower needs to keep the airflow cool, which is challenging to do in an outdoor crop; in fact, heat constitutes a strong threat which can stress the plants and affect their productivity.

    3. Cheaper compared to growing indoors

    Growing weed outdoors in a greenhouse is undeniably cheaper than growing it indoors. Indoor cultivation requires artificial light, ventilation and heating, which are costly to purchase and expensive to operate.

    Growing weed in a greenhouse: what do you need?

    A greenhouse is not suitable for everyone. You will require a garden as a minimum. Besides, there are some other things to think about:

    1. Location
    2. Greenhouse
    3. Pots
    4. Suitable strains

    1. Location and security

    If you live in a street with neighbours able to see into your garden, a greenhouse offers better security from prying eyes than growing outdoors.

    If you live in a more rural area, you could even get away with growing more than just a couple of marijuana plants here and there among your “regular” plants. The critical thing to think about in this situation is the smell, which will be stronger.

    The structure of the greenhouse allows more security than planting in the open air because as it is an enclosed space, you avoid certain inconveniences such as visits of wild animals at night. However, discretion should be maintained if you live in a part of the world where cannabis cultivation is regarded as an illegal activity. Some growers paint the greenhouse glass with white shading paint to reinforce this isolation. You can find this at a garden centre, and it serves the dual purpose of preventing the greenhouse from getting far too hot on the warmest days during the summer. When you have a painted greenhouse, people will not be able to peer inside and identify what you are growing.

    The often heady aroma of growing weed is heightened in a greenhouse, and minimising this is also something to think about. One answer is to mix the weed plants with equally smelly plants that like similar growing conditions, such as tomatoes. This will slightly reduce the weed smell, but if the thought of the pungent smell worries you, we recommend investing in an in-line ozone generator to eliminate it almost completely.

    2. The type of greenhouse

    Greenhouses are available in many different sizes and styles and prices that range from under thirty euros to many thousands. The cheapest models use a flexible clear plastic mesh sheet which closely fits over a small plastic or metal pole frame. These polytunnels are extremely cheap, but you will only be able to fit one or two plants inside. Another option is a greenhouse that leans against an exterior wall of your house. This provides easy access to your plants, additional insulation for your property and your plants will benefit from heat from the house.

    If you have space, you could opt for a standalone greenhouse with plenty of room for many plants. However, small greenhouses are also made for people that live in a flat and only have a restricted amount of outside space, such as a small balcony. Polycarbonate greenhouses, for example, feature tough plastic panels instead of the traditional glass and are ideal if you are concerned about safety if you have small children running around. There is a greenhouse to suit you, whatever your budget.

    3. Growing weed in pots or planting directly in the ground

    Ideally, you should take advantage of the natural environment and plant seedlings directly in the soil, because this allows the plants to spread their roots better to produce more abundant crops. This also helps to avoid transplanting them constantly during their growth. They are also less likely to overheat and suffer from root burn.

    However, if you plan to move them around, it is best to grow them in pots. This is an excellent way to better control the amount of water and nutrients they receive, while this is more complicated when watering directly on the ground. Measuring instruments are easier to manage when the plants are in pots than if the crop is anchored in the ground, which allows for more in-depth monitoring. Containers are also useful if you have to move them out of sight in a hurry.

    When it comes to watering your greenhouse plants, you can choose from a wide range of possibilities; old-fashioned methods or more sophisticated dropper or spray watering systems. If you can afford it, you can invest in a hi-tech system that automatically provides water and nutrients to your plants.

    4. The right genetics

    Feminised varieties and autoflowers generally do very well in a greenhouse. Autoflowers, for example, typically take 100 days to go from seed to harvest, which is a very short life cycle.

    Never forget that high-quality seeds bought from a reliable source, such as, need high-quality soil. This will give your plants the perfect boost at the very start of their lives to lay the foundations for healthy growth right through the flowering phase. Without these two elements, your weed plants won’t achieve the impressive yields and enormous sizes of which they are capable.

    A greenhouse allows better planning and organisation since it is fully compatible with automated installations. But if you’re one of those who appreciate the rituals and customs of growing cannabis, it also allows you to tend to them every day.

    What better use could there be for your back garden? Never forget that inferior quality weed seeds will never produce connoisseur quality cannabis, no matter how well they are tended. Invest in the finest cannabis seeds you can get from a trusted company with a reputation for excellence, and enjoy cultivating your own cannabis in a greenhouse.

    Reading tip: best strains to grow in a greenhouse