You can get exceptionally good results growing weed in a greenhouse. That's what you can tell from photos of commercial weed farms. Acres of wall-to-wall glasshouses filled with beautiful, large and healthy weed plants. Wouldn't you like that too? Read here about the advantages and disadvantages of growing weed in a greenhouse and build your own greenhouse in the garden.

Why grow cannabis in a greenhouse?

Growing weed in a greenhouse always looks great. But why would you put the green goddesses in a glass or plastic greenhouse? To begin with, the greenhouse offers the best of both worlds. Free sunlight from Mother Nature and an enclosed space like the growing room. It turns out to be a golden combination for both commercial and amateur cannabis growers. With a little effort you can create the ideal climate for your weed plants. Let's take a look at the advantages and disadvantages.

Shaman from Dutch Passion, grown in a glass greenhouse.

Advantages of growing weed in a greenhouse

To get straight to the point: the advantages of growing weed in a greenhouse outweigh the disadvantages. You just have to have the space and a little growing experience is certainly a requirement. This is why such a weed greenhouse is a good idea.

The best of growing indoors and outdoors

As mentioned, you have the advantages of both indoor and outdoor growing. With an indoor grow for example you need artificial light, but you have full control over the circumstances. Also, the space is limited. Outside, the light is free, but you have to deal with difficult weather conditions. You can use more space. In a greenhouse you have free light, as much space as the greenhouse allows (often more than a grow tent) and full control over conditions.

Control over climate & conditions 

When growing weed, you have to control the climate and other conditions. Think of light, water, air circulation, temperature, humidity and many other things. That is the foundation of growing weed. In an indoor growing space you have much more influence on these conditions than you do outside. For example, you can decide when to water your plants or improve air circulation by hanging a ventilator. In a greenhouse you also have these things under your own control. At the same time, you benefit from the advantages of growing outdoors and the power of nature.

Discrete and unnoticeable growing

With a weed greenhouse you can grow discreetly. When you see a greenhouse, the average person will not immediately think of a weed plantation. You can also take extra measures by, for example, using green plastic when building a greenhouse. There is even translucent paint. In any case, growing in a greenhouse is a lot more undercover than growing out in the open in your garden.

From the outside you can't see that there are weed plants in this greenhouse.

Saving costs through reduced energy consumption

With growing indoors you need artificial light. A grow light and the energy it consumes costs money and besides that it is not at all allowed to grow indoors with tools. In a weed greenhouse this is not an issue. You can save on costs. Sunlight is free and because you are not using professional tools, growing is tolerated. As long as you do not bother anyone and do not have more than 5 plants in the greenhouse. [Meer weten over de legaliteit van kweken? Lees onze blog: “...”.]

Adding extra light in bad weather with grow lights

Usually you don't need light when growing weed outside or in a greenhouse. Yet it sometimes happens that the weather is bad for days on end and the plants do not get enough light. In that case you can supplement the amount of light with grow lights. As said: with greenhouse growing you have it all under control.

Less chance of plagues in a hermetically sealed greenhouse

Diseases and plagues are the biggest dangers in growing weed. With outdoor growing your weed plants are out in the open, giving bugs free rein and increasing the chance of fungi such as bud rot and mildew. In a grow space you often have fewer problems with this because you have the conditions under control. In addition, the growing space is hermetically sealed off, so spider mites and other pests are less likely to get to your weed plants. The same goes for a weed greenhouse. Close it hermetically and you have less chance of diseases and vermin.

Pests and insects like these spider mites can destroy your weed plants. Keep them away by growing in a greenhouse.

Better quality weed with good conditions

If you manage to perfect the climate in your greenhouse, the quality of the weed automatically goes up. When your plants get just enough light, always have sufficient water and nutrition, and can grow and bloom under the right temperatures and humidity, you are guaranteed top quality weed.

Putting weed the dark

Growing weed in a greenhouse is ideal if you want to put the plants in the dark. By putting weed plants in the dark you force them to bloom earlier by giving them no more than 12 hours of light a day at an early stage. This only happens naturally at the end of summer, but if you put them in the dark longer than 12 hours a day earlier in the year, they will flower earlier. You can put your weed plants in a dark tent every day and take them out the next day. Or you can put a black bag over your plants every day and take it down in the morning. All this is incredibly time-consuming. By simply pulling a tarpaulin over the greenhouse and closing it completely so that not even a ray of light can get through, you can also put them in the dark. Saves you a lot of time and effort. Put your weed in the dark and greenhouse growing is a match made in heaven! Read more about putting weed in the dark in our blog.

Growing for longer periods of time in a greenhouse 

Because you are in control, you can grow longer outdoors. Outdoor growers are bound by the season. That season lasts from about May to October/November. Outside this period there is not enough light for your weed plants to grow and flower. In a greenhouse you can do something about this. By hanging grow lights in your greenhouse you can start earlier in the year and finish later. Perfect!

Disadvantages of growing weed in a greenhouse

Of course, it is not all sunshine and roses. Growing in a greenhouse also has its disadvantages. To protect you from them, we have listed them here. Read these points carefully so there are no surprises.

Limited space

Your weed plants can grow as big as the greenhouse will allow. Earlier in this article you saw a picture of a flowering weed plant that came through the roof. That is actually not the intention. A lot of advantages of growing in a greenhouse are lost. Your space is no longer hermetically sealed, the conditions are less controllable, when the weather is bad it rains inside and of course it is anything but discreet. 

Adapt the variety you want to grow to your greenhouse. With most weed seeds you can see what the average and maximum height of the plant is. If your greenhouse is two meters high, choose a strain that will not grow taller than that. You can also limit the growth of your weed plants by using growing techniques such as topping, scrogging and LST. These will keep your weed plants smaller and you can also increase the overall yield!

Weed plants can grow too big for the greenhouse. Prevent this with growing techniques such as topping, scrogging or LST.

Glass and plastic block light

A weed greenhouse is usually made of glass, Perspex or plastic. The disadvantage is that they all block light. With less light you can potentially grow slightly smaller plants and have slightly less yield. Another thing to take into account is that seedlings and small weed plants can stretch due to the lack of light. Fortunately, most greenhouses are built with special materials that allow as much light as possible to penetrate. Plastic allows the least amount of light to penetrate. Perspex or Plexiglas comes in second. Glass lets in the most light, but unfortunately still not one hundred per cent. There is a difference in glass quality. You can read up on that when you are building your greenhouse. If you have the possibility to open your greenhouse when the weather is very nice, you can certainly do so. Make sure that you keep vermin out.

Costs for the greenhouse

A disadvantage that needs little explanation. A greenhouse costs money. You can get yourself a weed greenhouse for a few tenners, but if you want one of good quality and therefore light permeability, you have to go a little deeper into your pockets. The cost of buying a greenhouse does outweigh the cost of buying grow lights and increased energy costs. You can also choose to build your own greenhouse. Make sure you use sturdy and good materials..

You cannot move a weed greenhouse 

You cannot move a greenhouse. So choose the ideal spot before you start. If the neighbours complain, you have a problem. You cannot just pick up the weed plant and store it at a friend's place. A greenhouse is a fixed location and you have to settle for that.

Tips & Tricks for the weed greenhouse

Now that you know all about the pros and cons of growing weed in a greenhouse, we want to give you a few tips. We have experience with greenhouse growing. These tips & tricks have helped us.

  • Choose a spot with plenty of sun. The location of your greenhouse is of vital importance. Your weed plants want to be in the sun all day. Do some research and find the sweet spot in your garden.

  • Clean your greenhouse thoroughly before you start growing. Inside and out! This way they can take full advantage of the sunlight from the beginning. They can make good use of all the light, because the greenhouse already blocks out a little. If you have large plants in the greenhouse, you will not be able to clean the inside. So: first scrub, then sow!

  • Make sure you have enough room to move around. If your entire greenhouse is full, you will not be able to reach it to water and feed it. Besides, it is not good for the weed plant if its neighbour blocks the sun. Always make sure there is a path between the plants. Then you have space to move around and every part of every plant is getting plenty of sun.
  • Choose a suitable strain. One strain is not like the other. Some are better suited to indoor and greenhouse growing. You also have to take into account the size of the plant. The harvest month can be important and maybe you want a plant that will not smell so strong? Take a good look in our seedshop. Use the filters and find the right seed. Tip: plants that you can grow indoors are also suitable for growing in a greenhouse. Outdoor plants, on the other hand, often grow too big to fit into a greenhouse. But do you have a gigantic greenhouse and can you accommodate the 3 to 4 meter sativas? Go ahead, then!
  • Prepare the soil well. Whether you choose to put your weed in pots or in the ground: make sure you have healthy soil. In our blog “The best potting soil for weed” we explain in detail what you need to take into account.
  • Hang ventilators right away. One of the problems growers face is air circulation. If a greenhouse is completely sealed, little air will flow through it. Air circulation is essential for your plants. Without air circulation, there is a greater chance of disease, mould and vermin. The conditions are just not optimal and that is what you are doing it for in the end.

An excellent alternative to growing weed in a greenhouse is a state-of-the-art grow box. In our shop you can buy high-tech grow boxes that provide your weed plants with everything they need. You can safely place them indoors, they mask weed smells, have the best quality LED lighting and offer many other advantages. Check out theMiniGrow Box One ore the new Minigrow Box Case.