Cannabis micro growing how-to guide

Cannabis micro growing is the cultivation of cannabis in the smallest space possible. Modern LED panel lights and THC-rich compact cannabis strains mean that you don’t need to compromise quality when micro growing in spaces as small as 30cm x 30cm x 70cm (12”x 12” x 28”).

What does micro growing weed mean?

Most people tend to consider a 1.2m x 1.2m (4 foot x 4 foot) grow room to be ‘typical’ for home growers. These are often around 2m (~6 feet) tall. But many growers simply lack this amount of space and have to consider much smaller spaces suitable for just a single cannabis plant.

The smallest space for a single-plant cannabis micro grow tends to be around 30cm x 30cm (1 foot x 1 foot). With modern panel-style LED lights you can micro grow a small plant with around 70-80cm of vertical grow area. Choose the right cannabis seeds and appropriately sized grow container and you are all set for a successful crop, even in ultra-tight spaces with little elbow room.

When to consider micro growing cannabis?

If you want to enjoy top-shelf potency but you simply don’t have the space to grow more than a single plant, then micro growing cannabis is a serious option. Lots of growers enjoy micro growing a plant in a confined space. The costs are low, the amount of required space is low and the process is easy when you follow a few simple rules which will allow you to control the growth profile of your plant.

Indoor cannabis micro grow setup

When micro growing cannabis it’s useful to have realistic expectations of the likely results. With an LED light source likely to consume around 30-70W, you are likely to be achieving around a gram per watt.

So a yield of around 50g is a realistic maximum. But even though your final harvest weight may be compromised from a cannabis micro-grow your quality need not be. Especially if you start with high-end autoflower seeds or photoperiod feminised seeds of a compact THC rich strain.

Suitable grow room / grow box for micro growing

You may be able to find a small dedicated grow tent. Some manufacturers produce small tents for clones/cuttings, you will need one with a minimum height of around 70-80cm tall and around 30-40cm wide/deep.

Alternatively, perhaps you have a small closet/cupboard that is a suitable size. DIY enthusiasts may even feel confident enough to convert a small bedside cabinet, fridge or cupboard. Remember you just need enough space for a single small sized, short cannabis plant.

The right pot size and amount of soil in a micro grow

The size of growing container you select for your micro-grown cannabis plants determines the available volume for the root network. The larger the available root space, the larger the growth potential for your cannabis plant. Cannabis micro growers, therefore, like to use smaller containers to deliberately limit the size of the resulting plant.

Plant pots around 3 litres in size are popular with cannabis micro growers and often support plants that reach around 25 – 30cm, though this may depend somewhat on the strain and your specific conditions.

You may wish to experiment a little. Some cannabis micro growers prefer slightly larger containers, from 5 litres up to an absolute maximum of 10 litre pots. But in general, pot sizes of around 3-4 litres support small plant sizes and are a popular choice with micro growers.

Related:
The cannabis root system, key to healthy plants

Understanding the advantages of LED grow lights

One of the essential components of a cannabis micro grow is a low power panel-style LED grow light. These can be placed much closer to your plants than ageing HPS light tech, which emit such high heat levels that they need to be kept a safe distance from your plants. That’s the main disadvantage of HPS lights for cannabis micro growers, they are simply not a good fit for small grow spaces when compared to LED.

Many growers tend to consider the best place for the grow light to be directly above their plant. A low powered LED panel can be placed within 10-15cm of the plant canopy. That makes great use of your available vertical growth space. But cannabis micro growing can also allow you to position your lights at the side of your plants.

This allows good light penetration as well as maximising your grow space. This allows you to consider the use of various low powered LED light panels, or even low power LED light bars which are often used for seedlings.

Ventilation and watering in a micro cannabis grow

Ventilation is one area where you may have to compromise a little more than you would like. In a small grow space, it’s important to provide ample fresh air to replace the Oxygen and Carbon Dioxide which is used by your plant. Many people use a small PC/computer fan (or similar).

Aroma control is one challenge for the cannabis micro grower. Small carbon filters are available, as are ‘flat’ carbon filters often used in the extraction hoods of kitchen ovens. The skilled DIY enthusiast may try to incorporate carbon filtration of extracted air. But in reality this is difficult in a small space. And with a single, small plant the aroma will be lighter than that from a large tent with 9-10 plants. Some cannabis micro growers place their grow in a well ventilated area, perhaps with an open window nearby to help disperse aromas.

Proper ventilation of your cannabis micro grow is essential but carbon filtration may not be easy. This is one of the compromises of the micro grower, it may not be easy to fully eliminate the cannabis odour. Good ventilation in your room or apartment will be required.

With just a single plant to consider, manual watering should be easy enough. And with a small micro grown cannabis plant the daily water requirements will be modest anyway.

Applying suitable grow techniques for a micro grow

Cannabis micro growing benefits from short bushy plants. Your choice of cannabis seeds will play a major role in determining the size, shape and nature of your final plant. But you can also manipulate the plant using different low stress training and high stress training techniques.

LST, cannabis low stress training

Gently tying down the tallest central bloom and side branches can create a low height cannabis plant with a flat canopy. Many cannabis micro growers find that LST is one of the most useful grow techniques to allow your plant to fit into a small grow space.

Related:
Cannabis low stress training for better yields

High stress training with cannabis micro grows

Another, perhaps more severe, option to control plant height is to use a high stress training (HST) technique such as topping (or FIMing) your plant. By removing the growing tip (or ‘apex’) of your plant the height potential is decreased and side branching is favoured instead.

Related:
Topping cannabis, how to do it, when and why

Defoliating cannabis plants and how to do it correctly

One other useful technique when micro growing cannabis is to defoliate your plants when required. Removing excess foliage allows better light penetration to the bloom points and can improve final yields. Just be careful not to over-defoliate your cannabis plant or you may stunt (limit) future growth.

Related:
How to defoliate cannabis plants for better yield

Consider the SCROG technique to create a flat canopy and a low-height plant

Although SCROG (Screen Of Green) method can be a little tricky/fiddly to implement in a small grow space the results could make a significant different to your cannabis micro grow. SCROG will create a flat canopy maximising use of the available grow space.

A SCROG cannabis micro grow will also place all your developing buds in the optical sweet spot of optimised light intensity. One great Dutch Passion strain for a SCROG grow is Desfrán. She is perhaps Dutch Passion’s purest sativa strain and can triple her height during bloom. Her long, pliable branches make her an easy strain to fill a SCROG net. Available in feminised seeds or autoflowering cannabis seeds (as Auto Desfrán).

Related:
Growing cannabis with the SCROG method

Using of the super cropping technique may help cannabis micro growers

Another technique that is useful when cannabis micro growing is super cropping. This is where the grower deliberately crushes the stem in order to bend it and lay it in a horizontal position.

This helps maximise use of vertical growth space. One recommended Dutch Passion strain which will respond well to super cropping in a cannabis micro grow is Amsterdam Amnesia.

The slender sativa leaves allow light penetration through to lower bud sites and the tough genetics cope well with high stress training. Amsterdam Amnesia can stretch a little during bloom but delivers heavy quantities of extremely potent buds. Perfect for the micro grower!

Related:
Cannabis super cropping, how-to guide

When to switch cannabis to bloom in a micro grow

If you have been wise enough to select a non-stretchy strain it will probably only double its height during bloom. Therefore, you may want to allow your photoperiod plants to reach around half the height of your grow space before you switch to 12/12 bloom conditions. That assumes you are growing photoperiod feminised cannabis seeds.

Many cannabis micro growers enjoy the speed and convenience of growing autoflower seeds. These will grow from autoflower seed to harvest under a fixed 20 hours of daily light and will switch to bloom automatically.

Best cannabis seed genetics for micro growing

Often growers will lean towards less stretchy indica or indica dominant strains. These tend to be a little more straightforward to manage than a super stretchy sativa. That said, many sativa connoisseurs find the thin fingers of the sativa leaves ideal for light penetration in a cannabis micro grow.

True sativa fans that insist on sativa cannabis genetics will often opt to use a short veg period or even grow their plants in a 12/12 schedule from feminised seed. They may often have to use training techniques to manage stretch, but many achieve good results.

Many cannabis micro growers prefer not to compromise on their strain choice at all, instead they will adapt the grow to accommodate their strain of choice. If you are undecided, the following strains are all great choices for cannabis micro growers.

Auto Blackberry Kush

Compact/fast indica autoflower with high THC levels.

Auto Blackberry Kush is compact indica autoflower. She often naturally stays at (or below) 75cm, even in large containers. Some phenotypes are ready to harvest in as little as 9 weeks after autoflower seed germination. Perfect for the cannabis micro grower seeking a fast, compact crop. THC levels are very high, yields are heavy and many plants will show beautiful blue/purple hues. A perfect way to unwind at the end of the day with superb anti-anxiety effects.

Kerosene Krash

Photoperiod feminised indica seeds with epic THC levels.

These cannabis cup winning photoperiod feminised indica seeds produce some of the highest THC levels ever seen by Dutch Passion. Expect THC levels of around 25%, even in micro grow conditions! Kerosene Krash feminised seeds use proven genetics from Gorilla Glue x Sherbet and deliver buds that reek of fresh fuel. You will get compact plants, especially when grown in small containers.

Auto Banana Blaze

Compact easy-to-grow indica autoflower strain.

Auto Banana Blaze is one of Dutch Passion’s most popular autoflower strains. She produces heavy yields of Afghani Kush buds from her compact and heavy yielding cannabis genetics. Auto Banana Blaze is also one of the most affordable strains ever produced by Dutch Passion, a 3-pack of these very high THC autoflower seeds costs little more than a round at the bar with a couple of friends. But the results are very special indeed, hard indica buds with a rapid stress-busting effects and a sweet banana taste. Auto Banana Blaze plants tend to stay very low and are well suited to cannabis micro growing.

Autoflower cannabis micro grow specificities

Autoflowers combine ease of growth with rapid 11-week seed to harvest grow cycles. Many indica autoflower (or indica-leaning) strains are naturally compact with minimum stretch and are well suited to the cannabis micro grower. Remember to research the options carefully.

You may find it easier to start with proven, compact autoflower strains and monitor yields/plant size with various container sizes. You may also find it easier to start with autoflower strains that have a reputation for fast growth and short size, such as Auto Blueberry, Auto Blackberry Kush, Auto Mazar etc before moving onto other autoflower strains.

How to grow small plants with big buds

The grow room and conditions will often largely define the type and size of your plant. The type of cannabis seeds you grow often defines the quality of the eventual harvest.

Do your research carefully and select some easy-to-grow cannabis strains that will deliver connoisseur quality results in combination with the low-stretch and small plant sizes you seek.

Cannabis micro growers may only grow a plant or two in a small space, but there is no need to compromise quality whatsoever. Many cannabis micro growers slowly refine their grow, eventually optimising their grow space, lighting and plant training techniques for their preferred cannabis strains. Master the fine art of cannabis micro growing and you will be surprised at the quality and quantity of buds that you can produce in impossibly small grow spaces!