Even in a smaller space, you can grow like a pro. Micro growing is for those who want to grow good buds stealthy and in a small discreet growing space. Achieving the biggest possible harvest in the smallest possible grow room; that's essentially what micro growing is about. Read all about micro growing.
What Is Micro Growing Cannabis?
Growing your own cannabis has been gaining a lot of popularity, people who can’t find good quality flowers or don’t want to deal with dealers are starting to grow their own. Even though it may seem super hard and expensive, having your own growing space doesn’t need to be hard at all, you can grow like a pro indoor, even in smaller spaces.
A micro cannabis grow consists of scaling down a grow tent, the only difference being the amount of space available. This results in a fully functioning indoor growing space that can fit in a small closet, a homemade grow box or even smaller spaces like a computer case or a cupboard.
1. Cannabis growing conditions
Just like in all other growing setups, you will have to provide a good environment for your plants to grow, this can be a bit hard when dealing with small spaces but it’s not impossible.
For your plants to grow properly, you will need to provide and maintain a relative humidity in between 60-50%, a temperature ranging from 18-25°C and 18hs of light for autos and photos in the vegetative stage, and 12/12 for photoperiodic strains in the flowering stage.
Despite being smaller, the growing space needs to have everything a normal-sized growing space has, so you won’t need to spend too much but you will need the basics.
There isn’t a big difference when growing in a small space, obviously you’re limited by the space you have available so you’ll have to choose the genetics wisely and perform plant training but other than that, it’s basically the same.
The challenge when micro growing cannabis is to be able to provide and maintain a good growing environment for your plants, this can be difficult when growing in small spaces but it’s not impossible, you most likely won’t get it right the first time but after making minor adjustments it will work like a charm.
3. Main requirements
Providing the needed amount of all these elements is crucial if you want to have a successful harvest, you will not need to spend too much or buy super expensive equipment but remember that when growing indoors you are responsible for controlling the environment your plant grows in so these things are obligatory.
Micro growing setups are usually homemade, it doesn’t really matter the material or size of the grow box as long as you provide everything your plant needs and that is:
Light is a key element in plant growth, obviously you won’t need a high-intensity light fixture but you will need to provide the appropriate amount of light for your plants to develop.
You cannot grow cannabis without light, that’s a fact. It doesn’t matter what kind of light you use either an LED or light bulb, now, light bulbs emit heat but can be near the plants while LEDs don’t emit much heat but can bleach your plants if they’re too close to the plants so depending on the growing space you will have to choose one or another.
Because of the limited space, you won’t have a lot of plants so you can also use fluorescent tubes and CFLs but remember to provide at least 400w per m 2 and have in mind that when using light bulbs you have to use white lights in the vegetative stage and yellow lights, almost all LEDs are full-spectrum so you won’t need to worry about this if using LED fixtures.
It’s essential you provide a wide light spectrum if you want to get dense buds so make sure you take extra caution before buying the lights. A common query when designing a micro grow is where exactly the lighting should be placed. Traditional grow rooms have the main light fixtures placed directly above the plants, with auxiliary lights sometimes added in various places throughout the grow room.
Since micro grows are often short on space, this traditional method may not be the best option. If you are going to grow in a tall vertical space with a small footprint it may be better to hang your light alongside the plant. This can be done on one side, but if possible it is better to cover multiple sides of the grow compartment with light sources. This helps with light distribution and penetration through the entire canopy and can help combat any stretching issues you may encounter when lighting from above only.
Ventilation and Air exchange
Like said above, plants need CO2 to perform photosynthesis. There are around 400PPM of carbon dioxide in the air we breathe so there’s no need to provide more than what’s already available but you will need a way to exchange air.
Because the space is limited and you don’t need and can’t fit an exhaust fan, you can achieve this just by having the door open or a couple of holes for the air to naturally circulate, this way you avoid having problems.
If you don’t make sure the air is exchanged several times a day, your plants will not be able to grow properly because they need CO2 to perform photosynthesis.
You will also need a small fan to help the air circulate, this will not only help exchange air but will also prevent bugs and make your plant’s branches and stem stronger.
Plants need macro and micronutrients to grow properly, if the medium is sterile and you don’t feed your plants, they will start to show nutrient deficiencies and can stop growing at all.
Because the pots are usually smaller and contain a smaller amount of soil (or the medium of your choice) you will have to water more often and maybe divide the nutrient dose you would give once in two or three, this will help your plant absorb it easier because the medium can only hold a limited amount of water.
Have in mind that you can grow photoperiodic strains but you can have trouble controlling their height so if you’re a beginner grower it’s better to start with autoflowering plants so you don’t risk ending up without a harvest.
Appropriate pot size
As you may know, the size of a plant is a reflection of the size of the roots so using smaller pots is necessary in smaller growing spaces, because the pot is smaller and will have less medium, you will have to water and feed more frequently.
Even though the size can vary from strain to strain, here’s a chart to help you have an idea of the approximate plant size for smaller pots:
|Pot size||Plant height|
This will also keep the branches shorter but depending on the strain, your plant can develop a lot of branches that you will have to control with plant training techniques if needed. The figures shown in the table above are just a general guide. Exact plant sizing will be dependent on which strain to type you opt to grow, and which growing techniques you implement. For micro grow setups, pots no larger than 2 to 3 liters are recommended. Some growers prefer to use larger pots and grow fewer plants, but a good general rule of thumb for maximizing yields in small grow areas is to go with more plants in smaller pots.
4. Choosing the strain
Because of the limited space, you will have to choose the right genetics so you don’t have a problem further into your plants growth cycle.
In this type of setup autoflowering strains are ideal, although some strains grow taller than others, so you have to be careful and pay attention to the information the breeders give.
For example, if your growing space is tall and narrow you’ll be better with Sativa-dominant strains, Sativas grow tall and skinny and are better for this kind of grow space whereas Indica-dominant plants grow short and bushy and are better suited for shorter and relatively wide.
Sativa dominant strains are known to increase in size by up to 200 to 300% during the flowering stage, whereas most Indica dominant varieties show increases in size closer to 65 to 130%. Certain Autoflowering strains are great for micro growing as they can be grown under multiple light schedules with some strains having a tendency to stay small and compact.
5. Plant training
When growing cannabis in a limited space, plant training is essential. There are a lot of plant training techniques that not only allow you to control the size your plant will have and even out the canopy but also help improve yields.
In small growing spaces there are a couple of growing techniques that are recommended:
Tying down branches
The tie-down method is fairly easy but you won’t be able to grow more than 2-3 plants in a limited space, this is because tying down the branches allows you to control the height by training your plant to grow to the sides.
You can also use high stress training techniques like topping or fimming but to effectively perform these techniques you need a bit of experience, HST techniques are not recommended with autoflowering strains but can be used with photoperiodic cannabis so you have to know what you’re doing so you don’t risk your harvest.
By choosing the better-suited strain for the space you have available you won’t have a problem, and if it grows a little bit more than what you expected, you can use any plan training technique you find appropriate.
Screen of green (aka Scrog ) consists of having a trellis net on top of your plants, this will not only allow you to control height but will also open up the branches so your plants have more airflow in the buds and also allows the light to reach deeper.
A sea of green (aka Sog ) is the most appropriate technique for this type of cannabis grow, it consists of having a lot of plants, growing small and not producing too much individually but will add up to a lot after harvesting all of them.
The plant training method you use will depend on the space you have, remember you don’t have to use just one, you can combine (for example) the Scrog method with the tie-down method to reach the desired height and structure. Keep in mind that auto-flowering plants tend to struggle with any aggressive plant training. High-stress training can halt vegetative growth for a few days all the way up to a week or more. These techniques are fine for photoperiod plants as they can be forced to stay in the vegetative stage by keeping the light schedule to 18/6.
Autoflowering plants have an inbuilt timer, with the vegetative stage usually lasting 5 to 6 weeks before they automatically start flowering (hence the name autoflower), no matter what light schedule they are grown under. Be sure to treat autoflowering plants like the princesses they are, keep any stress training to a minimum, and handle them with the care they deserve!
6. In conclusion
You can grow cannabis in any space as long as you provide the basic elements a plant needs, it doesn’t matter if it’s a huge or a tiny growing space.
If you have experience with this type of growing, please feel free to share your tips and tricks in the comment section below!
What is the difference between micro growing and regular indoor growing?
Achieving the biggest possible harvest in the smallest possible grow room; that’s essentially what micro growing is about. And the cannabis plant is highly suited to that. It’s ideal if you don’t have space or a big budget for a grow room. Or maybe you just feel like carrying out a fun experiment? This article tells you all about micro growing.
Although cannabis normalisation and legalisation are gaining momentum around the world, finding clean, good quality cannabis is not always easy. This is a pity, because good quality is very important for health purposes, especially for medicinal use.
The only way to be 100% sure about the origin and quality of cannabis is to grow it yourself. But not everyone has enough space or budget to set up a good grow room. And if growing outside is not an option due to an unfavourable climate, because your neighbours won’t tolerate it or because the law doesn’t allow it, you are totally dependent on others. Fortunately, the cannabis plant provides you with more options than you think. What about micro growing?
What is micro growing?
The advantage of indoor cannabis cultivation is the ability to monitor the growing process. In a grow room, almost all circumstances can be optimised. This allows the cannabis plant to grow and flower in a perfect environment. Obviously, out in the open a plant can become quite large, because a pot hinders root formation. But at the same time you have no control over the climate outside, while you do inside. Inside, you have complete control over the light, temperature, air circulation and humidity, and of course water and nutrition. These ideal conditions are essential for a healthy plant and also for a decent yield.
Micro growing is more or less the same as regular indoor growing. There is only one major limiting factor: the available space. Which is much smaller. Really a lot smaller! Examples include a computer cabinet, an old speaker case or a small home-made grow box. The challenge is to create the optimum conditions in which to grow as many plants as possible in that small space. Or to allow one single plant to grow to its maximum size, within the limits of the micro growing space.
Cannabis plants and techniques using micro growing
The number of plants that will fit in a micro growing space depends on the size of the space and the cannabis strain chosen. The use of growing techniques to influence the size is also a determining factor.
In micro growing spaces, you should ideally opt for an Indica-dominant strain, such as our Northern Lights or Hindu Kush. Indicas remain smaller compared to Sativas. The length of an Indica also increases by 50 to 100% during the flowering phase, while Sativas undergo a 200 to 300% increase in height. So if the flowering of an Indica is activated once it has reached the middle of the growing space, it is likely that it will finish just below the ceiling.
You can activate the flowering phase of a cannabis plant by shortening the number of hours of light per day suddenly from 18 to 12 hours. Read more about activating the flowering phase of cannabis plants in this article.
A good alternative is autoflowers. Whatever the conditions, these strains remain smaller. These plants, moreover, are not sensitive to the number of light hours to activate the flowering phase. They can be placed in 18 hours of light per day for the entire cycle.
The Difference Between Craft and Commercial Cannabis, And Why You Need to Know
Soil quantity for a cannabis plant
But there are more tricks available to affect the size of the plant. Most plants and trees have just as much volume under the ground as above the ground. This also applies to the cannabis plant: the amount of soil which the plants have at their disposal has a large influence on their size. The available space for soil is limited with micro growing, but below is a list of averages to give an impression:
- approx. 0.5 litre: plant height of up to 13 centimetres
- approx. 2 to 3 litres: plant height of up to 30 centimetres
- approx. 5 litres: plant height of up to 60 centimetres
- approx. 12 litres or more: average plant height
Topping, FIM and super cropping
Three techniques that affect the size of the plant are topping, FIM and super cropping. With these techniques, you can influence the height of the plant to create more of a bush-like shape.
With topping, you cut or trim the highest shoot off the main stem. This stimulates the plant to create two new shoots. Instead of a single shoot growing vertically, there are now two growing horizontally. Extra buds also grow on the second shoot, which means more yield.
FIM stands for “Fuck, I missed.” The story goes that someone didn’t properly perform the topping technique and cut off the shoot too high up. When this technique is performed correctly, new branches grow in addition to the two new shoots, which generate more yield.
Super cropping resembles topping. But instead of removing a shoot, the main stem is double-folded at the top until the interior of the stem snaps. The plant ‘thinks’ that the main stem is gone, whereupon it focuses completely on the underlying branches. The broken main stem will eventually recover, but will not grow very high.
Screen of Green
Like topping, FIM and super cropping, the Screen of Green technique (SCROG) arose from a desire to get more yield from plants. The main objective of SCROG is a uniform light distribution over all the flowers. But SCROG is also a good method to control plant height.
With the SCROG technique, a wire mesh is placed between the soil and the light source. Examples are chicken wire or similar. Once the trunk and branches grow through the screen, they are tied with thread to the wire mesh so that they do not continue to grow in length. They are instead guided over the screen. This creates a screen full of branches and tops that all remain at the same level. It’s a good way to manage the length, while all tops get the same light, which improves the yield.
Lighting in a micro growing space
In order to grow, a cannabis plant needs light, air and water. So however small the cabinet, a lamp must be present for light and heat. A lamp timer is also essential to activate the flowering phase, by switching from 18 to 12 hours of light per day (does not apply to autoflowers). The light source can’t be too large or have too much wattage. A high wattage creates too much heat in a small grow room. Be sure to hang a thermostat in the grow room. Fluorescent, CFL (energy saving lamps), HPI and HPS lamps with a very low wattage and LED bulbs are particularly popular with micro growers.
Fluorescent lights and energy saving lamps
Fluorescent tubes are inexpensive, have a good light output and their shape allows them to spread the light well. Also, fluorescent lighting is available in different light colours. A growing plant requires more blue light while a flowering plant requires more red light. Neutral light and warm white are common colours with fluorescent lamps and meet this need.
In terms of wattage, 400 to 450 Watts are required per square metre. So in a micro growing room of, for example, 60 x 40 cm (0.25 square metres) with 18 Watt fluorescent lamps, 6 lamps are needed. For additional illumination, it’s a good idea to make the ceiling reflective so that the light output fully benefits the plants. Place the VSAs outside the cabinet so that it does not overheat.
Energy-saving lamps are almost the same as fluorescent lamps. There are a few major differences. The VSAs are built in and the glass of the lamp is folded. The range of light colours is also limited.
HPI and HPS
HPI- and HPS lamps have been favoured by indoor growers for years. That’s because they have a high light output. You can use these conventional grow lights in micro growing spaces as well, but it is not ideal. The lower wattages are harder to find and they tend to become very hot. As a result, the plants can’t be placed too close to the lamps. This requires space, which is precisely what you don’t have with micro growing.
Much can be written about LED lighting. For this article, it suffices to know that LED is ideal for all light colours. It takes up little space and is not very hot, so plants can be placed close to it. However, good LED grow lights are expensive and therefore not as cost-effective for micro growing.