Growing Tips

Growing Tips & Topics


What is cocopeat?



What is Molasses and why do we use it?


Epsom Salts

What is Epsom Salt and why do we use it?



Aphids and how to deal with them.


Spider Mites

Spider mites and how to deal with them.


Fungus Gnats

Fungus gnats and how to deal with them.


Mulch Covers

Mulch covers and their uses.


Hydrogen Peroxide

Hydrogen peroxide and its uses.


Diatomaceous Earth

Diatomaceous earth and its uses.


Sea of Green

What is a 'sea of green'?



What is a 'SCROG'?


Cannabis Seeds

What are the different types of seeds?


Grow Lights

What are the different types of grow lights?


Strain Names

Types of cannabis plants and what their strain names tell us.


Grow Bags and Plastic Pots

Why we choose bags over pots.


Grow Boxes

Why we choose grow boxes, and how to make your own grow box at home.


White Powdery Mildew

White powdery mildew and how to deal with it.


Germinating Seeds

How to germinate your cannabis seeds.


Low Stress Training

What is Low Stress Training (LST)?


What is Cocopeat?


Cocopeat, also often referred to as coco coir, coir, or kokos, is a product made from coconut husk, and is used as a growing medium for any plant, vegetable, or fruit grown in soil. Cocopeat is dark brown in colour, with a granular, spongy texture; it consists of coconut pith and coconut fibres.

Cocopeat is used globally by professional growers of any growing products: large-scale cannabis producers, wholesale nurseries, tunnel farmers, seedling growers, fruit tree growers, landscapers, and horticulturalists, to name but a few.

Benefits of using cocopeat:

Exceptional water-holding capacity: Cocopeat consists of millions of micro sponges, and it can absorb up to 1000% of its own weight in water in its dry form. This means that the cocopeat that is added to our Just Cannabis Soil can help you save and preserve water usage, and it reduces the risk of drying out the root zone of your growing medium.

Increased AFP / aeration: The coco fibres contained in cocopeat assists in raising the AFP (air-filled porosity) of the growing medium that cocopeat is added to. When the AFP in the root zone is higher, more oxygen is produced, which is a crucial element in promoting strong and early root development for your cannabis plants.

Stimulates beneficial soil microbes: As a result of the balanced combination of water-holding capacity and AFP present in cocopeat, cocopeat helps to create a perfect climate and environment for important and beneficial soil microbes to thrive in our Just Cannabis Soil.

Environmentally-friendly and sustainable: Coconuts, the primary source of cocopeat, have a low environmental impact; coconuts are harvested by hand, and do not require pesticides or herbicides to be grown. This makes cocopeat a much more environmentally-friendly and sustainable source of growing medium in comparison to other growing mediums, such as peat moss (which is produced by strip-mining topsoil in ancient forests).



Blackstrap molasses is a by-product of the sugar cane’s refining process, and is a dark viscous liquid that emerges from the third boiling of sugar cane juice. Due to the multiple boiling process that is undertaken in the production of blackstrap molasses, it is a highly-concentrated product, and it contains many beneficial elements (such as iron, calcium, magnesium, and potassium) on both a micro- and macro-level.

Sulphured and Un-sulphured Molasses

Sulphured Molasses refers to molasses that contain sulphur dioxide (SO2), whereas Un-sulphured Molasses refers to molasses that do not contain sulphur dioxide.

Oftentimes, sulphur dioxide is added to sugar cane as a preservative and as an antimicrobial, maintaining the freshness of raw sugar cane until it is processed. However, sulphured molasses tends to kill the beneficial microbes which are found in soil, which is why our Just Cannabis Blackstrap Molasses is un-sulphured.

How does Blackstrap Molasses promote the health of your cannabis plants?

The most important factor in maintaining the health and vitality of your cannabis plants is the quality of your soil. Good soil should contain (amongst many other compounds) important nutrients such as micro- and macro-elements, and vitamins that are essential for maintaining the health of your cannabis plants.

Furthermore, good soil also contains living microbes, or micro-organisms. Introducing un-sulphured blackstrap molasses into your soil ensures not only the maintenance of nutrients in your soil, but also ensures that these micro-organisms are being fed, facilitating the ideal environment for these microbes to flourish.

Maintenance of salt levels, and prevention of nutrient deficiencies

A common problem that arises in growing cannabis is the gradual build-up of salt in your growing medium. This problem is more persistent when utilizing inorganic and mineral-based synthetic fertilizers and supplements. When salt builds up in your soil, the increased PH levels and EC levels prevents the absorption of sufficient nutrients, a problem often referred to as Nutrient Lockout. By using natural, un-sulphured blackstrap molasses, the salt levels of the soil are maintained, thus allowing for adequate absorption of nutrients.

Epsom Salts



Contrary to the name, Epsom Salt is not salt, but rather a mineral compound of magnesium, oxygen, and sulphate (MgSO4), which exists naturally in water and springs. Epsom Salt is a white, powdered crystal, and is similar to table to salt in its appearance.

Epsom Salt is different from commercial fertilizers in that it is not persistent, and therefore will not build-up in the soil, nor affect the PH levels of the soil.


Epsom Salt is a natural and healthy source of magnesium. The presence of magnesium (Mg) in plants is essential in aiding the process of photosynthesis, the process whereby plants convert sunlight into food.

Magnesium (Mg) is important for maintaining the strength of plant cell walls, and the uptake of nitrogen (N), phosphorous (P), and potassium (K) is facilitated by the presence of magnesium.

When your cannabis plant is suffering from a magnesium deficiency, the leaves tend to yellow, starting at the lower sections of the plant, and resulting in a slightly curled leaf. (NOTE: if the leaves and the vein of your plant start to yellow, then it is suffering from a nitrogen deficiency).

Here at Just Cannabis, we use Epsom Salt as a source of magnesium rather than other soil amendments (such as dolomitic lime, for example), because Epsom Salt is highly-soluble, making it easier to apply. The PH levels of Epsom Salt solutions are closer to neutral, in contrast with the high alkalinity of magnesium salts found in limestone.

Thus, to achieve higher yields and bigger buds, magnesium is a key ingredient, and Epsom Salt is the best source.



Aphids are small sap sucking insects and members of the superfamily Aphidoidea and the family Aphididae. There are many different species (more than 5,000) in the aphid family.

Aphids come in a variety of colours like green, yellow, black, red or brown. Their bodies are oval shaped and if you look very closely you will notice that they have long whip like antennae.

An aphid infestation normally starts with a few adults feeding on a plant. If the plant is a suitable host, these scouts deposit approximately a dozen wingless nymphs, through an asexual form of reproduction called parthenogenesis.

These female nymphs feed on the sap of the host plant and can produce numerous offspring per cycle. As the cycle is repeated throughout the spring and summer season the aphid colony grows exponentially. The host plant will soon covered in aphids. The aphids eat large amounts of sap from the host plant in order to get adequate nutrition. The aphids also excrete a substance called honey dew, which contains a high percentage of sugars.



Ants on your cannabis plants are often a sign of aphids. This is because the honeydew excreted by aphids attracts ants, who feed on the honeydew. The ants have a symbiotic relationship with the aphids and in return for honeydew the ants fiercely defend the aphids from insect predators. This might sound very farfetched, but it is scientifically proven ant behaviour.

The honeydew excreted by the aphids can also attract a type of fungus commonly referred to as “black sooty mould”. The black sooty mould grows on the honeydew deposits and colours the host plant’s leaves and stems black. Black sooty mould is usually a sign of an advanced aphid infestation.

Initially aphids tend to hide under the leaves of the host cannabis plant until such time as the infestation reaches larger numbers and then the aphids should be visible on the leaves and stems. The green variety of aphid may be more difficult to spot at first due to the colour blending in with the leaves.

Due to the high amounts of plant sap that the aphids suck from the host plant you should see signs that your infested cannabis plants are struggling. These signs may include wilting leaves, curling leaves, yellowing leaves and general stunted growth of your cannabis plant.



Companion plants

A great environmentally friendly way of helping prevent an aphid outbreak is by making use of companion plants.

Companion planting is a process whereby the growing environment are improved by planting beneficial plants close to one another. Individual plants protect others against pests by emitting a strong odor that should help deter aphids from reaching your cannabis plants.

Some of the best companion plants for keeping aphids away from your cannabis plants are coriander, basil, dill, garlic and chives. For more information on companion plants please see the section on companion plants.


Outdoor Growing

Aphids spread by winged colonizer females, who lay eggs on the new plants they wish to colonize. This means that outdoor growing areas are most at risk of an aphid infestation and that it is very difficult to prevent these winged colonizer female aphids form reaching your outdoor growing area. One way of keeping the aphids away from your outdoor cannabis plants would be to make use of companion plants as discussed above.

The best strategy with outdoor aphid control is to regularly check your plants (at least once a week), this will hopefully enable you to catch and control the aphids early on when the colony is small and manageable.


Indoor Growing

Indoor growing areas are less likely to be reached by winged colonizer females than outside growing areas, but aphids can still reach your indoor grown cannabis plants by other means - like bringing cannabis plants or clones into your indoor growing area from elsewhere/ outside. The answer to this problem is to only grow from seed in your indoor growing area or if you still decide to bring clones or other cannabis plants into your growing area from outside or elsewhere, you should quarantine these plants separately from your growing area for at least a week. Checking them regularly for aphids and other pests.

Even if you do not see any aphids or other pests (like red spider mites) during quarantine it is still advisable to dip the clone or small plants in a insecticidal soap solution before bringing them into your grow area. If you cannot dip the plants thoroughly spray them with an insecticidal soap solution.



If you find aphids on your cannabis plants a good first step is to prune off infected areas and dispose of it by putting it in the trash. After you have pruned off the infected areas you can try spraying off any remaining aphids with a garden hose (if possible).

If you are struggling with a heavy infestation of aphids, you can also spray your plants with an environmentally friendly insecticidal soap solution like Biogrow’s Neudosan. Please note that normal dishwashing soap is not insecticidal soap and using it could end up burning your plant leaves and not killing any aphids. It is very important to properly follow the instructions of the insecticidal soap you are using because if you do not accurately dilute the insecticidal soap you might end up burning you plants. One of the benefits of using insecticidal soap is that larger predatory insects like lady birds (lady bugs) won’t be affected if they come into contact with it in their adult form.

If the infestation still persists after trying insecticidal soap you can try spraying with neem oil. However be aware that the neem oil may also kill any other beneficial insects it comes into contact with. When using neem oil you should take care not to get it on your buds as it will leave a bitter taste and the effects of smoking neem oil coated buds on human health have not been properly studied (it could be harmful to your health).

If you see any ants on your cannabis plants you should eliminate them, because the ants will defend the aphids against natural predator insects such as ladybirds (ladybugs) and their larvae, tachina flies, parasitic wasps, praying mantises, lacewing larvae, hover fly larvae, tree crickets, small spiders and young assassin bugs.


Spider Mites


Spider mites – every cannabis grower’s worst nightmare.

Spider mites are members of the Acari family. There are over 1200 documented species in the mite family. Spider mites are less than 1 mm in size (between 0.4mm and 0.5mm), and they also vary in color. They have four pairs of legs, no antennae and an oval-shaped body. They lay small, round eggs which are transparent at first.

Many species of spider mites spin silk webbing to help protect the colony from predators. This is where they get the "spider" part of their common name. The best known member of the group is Tetranychus urticae, commonly known as ‘red mites’ or ‘two-spotted mites’. The idea of encountering these mites in one’s grow area is enough to make any grower shudder.

Spider mites generally live on the undersides of leaves of plants, where they may spin protective silk webs. They can cause damage by puncturing the plant cells, which is how they feed. Spider mites are known to feed on several hundred species of plants, but they particularly enjoy feeding on the sap and plant tissue of cannabis sativa. They know what’s good.

Hot and dry conditions are often associated with an infestation of spider mites. Under ideal conditions (approximately 27 °C), the two-spotted spider mite can hatch in as little as three days, and become sexually mature in as little as five days. One female can lay up to 20 eggs per day, and can live for two to four weeks. This accelerated life cycle allows spider mite populations to adapt quickly to pesticide resistance, so chemical control methods may become ineffective when the same pesticide is used over an extended period of time. This doesn’t matter to us because we don’t do chemicals. Ever.



Spider mites are so tiny in size that they often go unnoticed by the naked eye. (Investing in a jeweller’s loop is a great idea for any grower, and not just for checking out your ambering trichomes. Use it to inspect your plants thoroughly and regularly!) Upon closer inspection, spider mites appear like small amber or pale green dots. They are mostly found on the underside of leaves.

If you have no jeweller’s loop or magnifying glass, one way of checking for spider mites is to hold a piece of blank white paper under the leaves and carefully shake the plant. If you find peppery looking spots on your paper, it’s likely that you have a mite infestation on your hands.

Some initial signs of a spider mite infestation include tiny white spots or dappling of leaves. These little spots of discolouration are visible from the top of the leaf, too. Often, thin and silky webs can be found surrounding the underside of plant leaves and branches.

More serious infestations can cause leaves to turn yellow, become limp and die off altogether. A large spider mite infestation can have a remarkably detrimental effect on a cannabis plant. By attacking and destroying the plant’s leaves, they may stunt its ability to develop and grow; inevitably resulting in much lower yields.

Spider mites may also infest the surrounding areas of cannabis flowers, which can inhibit their ability to develop properly. In a nutshell; your buds will be small and lacking in both potency and flavour, and there won’t be a whole lot of them either.

Finally, a large enough colony can kill entire plants, although that is a very rare occurrence. The severity of such an infestation involves a level of negligence which ought to be punishable by death. Check on your ladies. Check on them every single day.



 Generally speaking, spider mites thrive in a hot and dry environment; while cooler, breezy and more humid conditions slow their reproductive rate significantly.

Owing to their incredibly tiny size, spider mites can quite literally float into your grow area on a slight breeze (or on a cloud of smoke, should they choose to arrive in style). They’re well-known for their windsurfing skills. If you’ve ever felt that you’re “too small to make a difference”, you haven’t encountered spider mites.

They are also often introduced to indoor grows from other house plants in the area, or from new plants and clones that have been introduced into the grow area without quarantining them first. Yes.. your buddies may often tempt you with cutting or clones from awesome genetics, but be doubly sure to keep them in quarantine for at least two weeks Mites have also been known to travel on shoes and clothing, as well as on the coats of your pets. Mites (including pregnant ones) can also lay dormant for extended periods of time, until the conditions are favorable enough for them to thrive again.

We’re quite sure that you are now beginning to understand why we started by saying that spider mites are quite possibly every grower’s worst nightmare. They are near impossible to prevent, extremely difficult to detect, and a huge ball-ache to eliminate.


The following are organic methods which can (and should) be put in place as a preventative measure. Prevention is ALWAYS better than cure, especially when growing with living soil and organic techniques.


  1. Companion plants

A great environmentally friendly way of helping prevent a spider mite outbreak is by making use of companion plants.

Companion planting is a process whereby the growing environment is improved by planting beneficial plants close to one another. Companion plants protect other plants against pests by emitting a strong odour that is said by many to help deter spider mites from reaching your cannabis plants.

Some of the best companion plants for keeping spider mites away from your cannabis plants include Chinese parsley, cilantro, coriander, dill, garlic, pyrethrum, fennel, cloves, chives and onions.


  1. Neem Oil

The application of neem oil every ten days acts as a preventative measure for pests and pathogens. Prevention is always the best policy. It is, however, very important to prevent neem oil from coming into contact with your cannabis flowers. For more information on neem Oil, please see the section on neem.


  1. Essential Oils

Eucalyptus, cinnamon, lemon, peppermint and rosemary essential oils are all useful in preventing spider mites when diluted heavily with water and used liberally as a foliar spray. Essential oils attack the nervous system of the spider mite, and they work well as a preventative measure. It is, however, very important to prevent essential oils from coming into contact with your cannabis flowers to avoid changing their taste and smell. No one wants to smoke peppermint flavoured Cheese, or eucalyptus flavoured Sour Diesel.



Once you’ve identified spider mites in your grow area, it’s imperative that you act immediately. It is essential to ‘attack’ all stages of the spider mite’s life cycle in order to combat the infestation most effectively. This is going to be hard work, but it’s not impossible.

The first option is to set your entire grow room on fire, and move to a new house. If this is not a plausible option for you then keep reading for a list of measures which should collectively assist in getting rid of your spider mite infestation.


 Pruning and cutting

The logical first step would be to physically remove as many of the mites as possible by pruning and cutting off any infected areas, including (and well past) the areas where any webs are found. Dispose of these off-cuts by sealing them an airtight bag and throwing them in the dustbin!

With severe spider mite infestations, it is worth considering destroying the affected individual plants entirely. This prospect is enough to bring a grown man to his knees, but sometimes “a man’s gotta do what a man’s gotta do”.



After pruning, gently hosing the plant down with clean running water may assist in physically removing some of the remaining mites.


Kill the adult mites

  • A massively successful (and 100% organic) way of eliminating the adult spider mites is by spraying a mixture of 35 percent food-grade H2O2 (hydrogen peroxide) and water onto the stems, leaves and ground cover. (Some of you might be thinking of your mother’s hair bleach right now, and wondering how that’s organic. Actually, hydrogen peroxide is just water with an additional oxygen molecule. Natural AF.) This mixture kills adult mites on impact, and is neither dangerous nor harmful for your plants at all - if implemented correctly and safely. It is recommended that this spray be repeated daily so as to eliminate the new mites as they hatch. It will not affect the eggs. The concentration of hydrogen peroxide and its correct dilution in water is of utmost importance: if it’s too strong you will burn your plants! For more information on H2O2 please see the section on hydrogen peroxide.
  • Ladybugs are also useful predator bugs that will devour spider mites at an alarming rate. The only downside of using ladybugs is that eventually when they run out of mites to eat, they will eat each other.
  • Dusting the soil, stems and leaves with diatomaceous earth during the vegetative stage of the plant is said to kill adult mites when they crawl over it or come into contact with it. The sharp edges of the diatoms pierce the soft tissue of the mites causing dehydration and death. Be careful not to inhale diatomaceous earth as it can damage the soft tissue in your lungs.
  • Spray your plants with a 1:1 mixture of rubbing alcohol and water. The alcohol will destroy the exoskeleton of the mites and create an unfavourable environment for them.


Kill the eggs

Mix Pure Neem Oil with water and apply every 3-5 days to kill spider mite eggs and interrupt the reproductive cycle. Make sure to spray all plant parts, including the undersides of leaves. Do NOT apply when temperatures exceed 21 degrees Celsius, and wait at last six hours before turning your grow lights on (if indoors).

Fungus Gnats


Fungus gnats are common pests of indoor plants, specifically when moisture and humidity are high. The interesting thing about fungus gnats is that it is not the actual flying gnat which concerns growers; it is the larva of the gnat in the soil which feeds on your cannabis plant’s roots.

Fungus gnats are members of the Mycetophilidae and Sciaridae family. Fungus gnats are less than 3.5mm in size, and they are greyish/ black in color. They have three pairs of legs, antennae and long transparent wings. They lay small eggs in the top layer of soil, which later hatch into larva. The larva are 6-7mm in size, and have long milky white bodies with shiny black heads.

Adult gnats live for about ten days, and lay up to 300 eggs in their lifetime. Within five to six days, tiny larvae emerge and bury down into the soil where they begin feeding on plant roots. The larva feed for 10 – 14 days before changing into pupae in the soil. After five to six days young adult gnats leave the soil and begin the next generation. The entire life cycle from egg to adult may be completed in as little as four weeks, depending on temperature.

An area infested with fungus gnats will be hosting the gnat in all stages of its life cycle. For this reason, it’s important to attack each stage to get rid of fungus gnats quickly and permanently.

They are most abundant in rich, damp soil; and they feed on root hair, fungi and other organic materials. In other words, Just Cannabis soil is the perfect environment for these little buggers, and they will be most attracted to it. Luckily, they’re not too difficult to deal with, and preventing them is even easier.



Spotting adult fungus gnats is relatively easy. Owing to their size, you will notice them flying around your grow area or running around on the surface of your soil.

The eggs and larva may also be seen in the top layer (first two inches) of the soil.

With more serious gnat infestations, your cannabis plants can develop the appearance of over-watering, nutrient deficiencies and PH problems. The leaves will show signs of ill-health, while younger plants or seedlings are at risk of total devastation.



Generally, fungus gnats thrive in environments with high humidity. Overwatering is the most typical cause of fungus gnat infestation.

Because they are flying insects in their adult stage, they are able to fly around in search of a favorable home if need be. They are attracted to the organic matter in rich soil, so keeping them at bay requires some attention.

The following are organic methods which can (and should) be put in place as a preventative measure. Prevention is ALWAYS better than cure, especially when growing with living soil and organic techniques.


Companion plants

A great environmentally friendly way of helping prevent a fungus gnat outbreak is by making use of companion plants.

Companion planting is a process whereby the growing environment is improved by planting beneficial plants close to one another. Companion plants protect other plants against pests by emitting a strong odor that is said by many to help deter fungus gnats from reaching your cannabis plants.

Some of the best companion plants for keeping fungus gnats away from your cannabis plants include marigolds, chrysanthemums, and pitcher plants.

Mulch cover

The use of a mulch cover is truly something that cannot be stressed enough. Mulch, mulch, mulch! Covering the surface of your soil with a mulch cover will prevent adult fungus gnats from successfully laying their eggs when landing on it. Quite simply put, the lifecycle of the fungus gnat cannot begin. For this reason, mulch covers remain the ultimate prophylactic for a host of pests, including the fungus gnat. For more information and ideas on mulch covers, please see the section on mulch covers.

Use a fan

Using a fan to circulate the air in your indoor grow area is of utmost importance, even without considering the matter of fungus gnats. A fan creating wind will assist in keeping the top layer of the soil dry, and will prevent adult gnats from being able to fly around and lay more eggs.



Once you’ve identified fungus gnats in your grow area, it’s time to attack the little bastards. It is essential to ‘attack’ all stages of the fungus gnat’s life cycle in order to combat the infestation most effectively.

The following are organic measures, which should collectively assist in getting rid of your fungus gnat infestation.


 Kill the adult fungus gnats

  • The logical first step would be to physically remove as many of the adult gnats as possible, and yellow sticky traps are incredibly effective in doing so. The adult fungus gnats are attracted to the yellow color, and when they land on the sticky trap they, well… stick to it. These yellow sticky traps are available at most garden centers or hardware stores in a variety of shapes and sizes.
  • Fill a small glass jar with apple cider vinegar. Pierce small holes in the lid and cover it. Place these glass jars in areas where there are high populations of fungus gnats. The gnats will crawl down into the vinegar and drown.


Kill the larvae

  • We recommend that you start by drenching the soil with a mixture of Margaret Roberts’ Biological Mosquito Insecticide and water (as per manufacturers instructions). This product works wonders as a microbial insecticide for fungus gnat larvae in the soil. It will kill off any larvae it comes into contact with, which is why we recommend that you drench your soil with it. Make sure you get all of those little suckers. After this exercise, you will want to make sure that you dry out the top layer of your soil as soon as possible.
  • A mixture of food grade H2O2 (hydrogen peroxide) and water can be used as a soil drench, and will achieve the same results as the above mentioned method. (Some of you might be thinking of your mother’s hair bleach right now, and wondering how that’s organic. Actually, hydrogen peroxide is just water with an additional oxygen molecule. Natural AF.) This mixture kills fungus gnat larvae on impact, and is neither dangerous nor harmful for your plants at all - if implemented correctly and safely. The concentration of hydrogen peroxide and its correct dilution in water is of utmost importance: if it’s too strong you will burn your plants! For more information on H2O2 please see the section on hydrogen peroxide.
  • Neem oil is another product which can be diluted with water and used as a soil drench to kill fungus gnat larvae.
  • Place slices of potato (about 3cm thick) on the surface of your potting soil, and check on them every four hours. Dispose of the larvae, rinse the potato and do it again. (According to us, this method is better suited for assessing the extent of the infestation than it is for combatting it. But hey, whatever works for you.)
  • Food grade diatomaceous earth in the dry, top layer of your soil will kill any larvae that come into contact with it. The sharp edges of the diatoms pierce the soft tissue of the larvae, as if they were crawling through shards of broken glass. Be careful not to inhale diatomaceous earth as it can damage the soft tissue in your lungs. For more information on diatomaceous earth, please see the section on diatomaceous earth.
  • Using a proper mulch cover will prevent any more eggs from being laid on your topsoil. Using a mulch cover is quite possibly the most effective way to control fungus gnats. For more information on mulch covers, please see the section on mulch covers.
  • The Hypoaspis aculeifer, more commonly known as fungus gnat predators, are useful predator bugs which can provide a slow and steady decline in the number of fungus gnat larvae. Fungus gnat predators creep around on the soil and feed on the larvae.


Mulch Covers


A mulch cover is one of nature’s finest prophylactics against pests and environmental harm.

Some would even argue that, in nature, mulch is the very first of the different layer of soil. In other words, mulch is such an integral part of a healthy environment for plants, that it can be seen in nature where it covers and protects the soil beneath it.

A mulch cover supports the microbial activity in your soil. It ‘covers’ it with an essential top layer, which assists in maintaining healthy conditions. It keeps the soil humid, and prevents water from evaporating too quickly. A mulch cover also keeps the top layer of the soil cool, allowing the roots of your plant to grow closer to the surface. The top layer of soil is usually warm and dry because of exposure to the sun (or grow lights), and your plant’s roots will seldom be comfortable to explore it.

Mulch also assists greatly in keeping pests at bay. The fungus gnat, for example, is unable to lay eggs in the top layer of soil if there is a mulch cover in its way. For more information on fungus gnats, please see the section on fungus gnats.

There are endless ways of creating a mulch cover. Essentially, a mulch cover can be defined as the “covering of the top layer of soil”. Below is a list of all the different types of mulch cover that can be used for your cannabis plants.


Find one that works best for you and the set-up of your grow.

  • Green mulch

Green mulch is better suited for more experienced gardeners. It consists mainly of insects and dead leaves, and provides a slow release of food for the ‘healthy’ bacteria in your soil. Green mulch is best used during the vegetative phase of your cannabis plant. It can affect the PH of your soil if you get it wrong, so be careful.

  • Brown mulch

Brown mulch is made up of sticks, twigs and other dead plant matter. It attracts fungi due to its acidity. A correct mulch balance is integral to maintaining the ideal PH. Brown mulch is best used during the flowering phase of your cannabis plant.

  • Plastic mulch

Plasticulture’ is a real thing. It involves the covering of the ground surrounding your plants with plastic.

Now usually we wouldn’t support the use of plastics - at all. Here at Just Cannabis we strive to be eco-friendly at all times. Even the packaging of our soil is made with 100% biodegradable ‘plastic’!

A very clever patron, however, recently changed our minds when he used the packaging bags of the Just Cannabis soil to create his own mulch covers. Genius!

  • Organic materials

By now you’re starting to get the hang of it. Making a mulch cover is really quite simple. Organic materials such as pine straw, grass clippings, leaves, and wood chips are popular.

  • Stones

Truly, we saved the best for last. Our favorite type of mulch cover is extremely simple and highly effective. Use small stones (5-6mm) to create a mulch layer on top of your soil – not more than 5cm thick. This type of mulch dries extremely fast, keeping the soil beneath it moist and fresh.

Hydrogen Peroxide (H2O2)


H2O2, more commonly know as hydrogen peroxide, is something that many growers are afraid to experiment with. This is partly due to lack of education on exactly what hydrogen peroxide is. A lot of people associate hydrogen peroxide with their mom’s hair bleach, and they believe that it’s some kind of ‘gnarly chemical’,

Water is H2O: two hydrogen molecules and an oxygen molecule. When an additional oxygen molecule binds to water, it becomes H2O2; two hydrogen molecules and two oxygen molecules.

Pretty damn natural.

Having said that, hydrogen peroxide can be really dangerous - if not used safely and responsibly. Hydrogen peroxide is available in different concentrations (or volumes), and can range from ‘mild to potent’. The volume of hydrogen peroxide that we work with is usually 35% food grade peroxide. This is an incredibly high volume, and can severely burn your skin, eyes and anything else it comes into contact with (especially when undiluted). (For God’s sake; please be careful!) Many growers opt to use a much lower volume of hydrogen peroxide (as low as 3%). At the end of the day the volume you choose will affect the dilution ratio.




Hydrogen peroxide is something that every grower should have in his or her arsenal. The following is a list of the many uses of H2O2 for your cannabis plants. Not all of these uses for H2O2 are suitable or recommended for use with our Just Cannabis soil.


  • Diluting hydrogen peroxide with water as a soil drench is a great way of giving the roots of your plants an oxygen This will help boost their root development. We do not recommend this treatment when using Just Cannabis soil, as the H2O2 will kill off the microbial activity in the soil.
  • Use a mild dilution of H2O2 and water to pre-treat seeds for fungal infections. A stronger dilution can be used for fungal infection and root rot.
  • Use hydrogen peroxide as a disinfectant for your gardening tools and grow area. A clean grow space is a happy grow space.
  • A H2O2 soil drench is a great means of disinfecting soil. We do not recommend disinfecting the Just Cannabis soil, as the H2O2 will kill off the microbial activity in the soil.
  • A mild dilution of hydrogen peroxide and water as a foliar spray is an incredible insect repellant and an insecticide. This mixture is safe enough to use on your cannabis plants every day, even on your buds! H202 kills an array of pests on contact; and if it doesn’t kill the pests, then it destroys their eggs. This is a must-have in your arsenal of pest prevention and control!

Diatomaceous Earth


Diatomaceous earth is a naturally occurring soft sedimentary rock, which is normally processed into a very fine, off-white powder. This sedimentary rock is made up of the fossilised remains of diatoms (small aquatic microorganisms).

Diatomaceous earth is rich in silica, and contains varying amounts of natural clays and trace minerals. Each deposit of diatomaceous earth is unique in its composition. Gardeners and horticulturists have long used diatomaceous earth for several purposes, with Bonsai enthusiast often seen planting their bonsais entirely in diatomaceous earth.

Food grade diatomaceous earth is incredibly safe and organic, but please be careful not to inhale it. The abrasive particles can damage the soft tissue of the lungs.


The following list mentions the various uses of diatomaceous earth in your cannabis grow.


  • Diatomaceous earth is extremely abrasive on a microscopic level, and the tiny particles cut away at the exoskeleton of insects as though they were crawling through shards of broken glass. Insects (and their eggs and larvae), which come into contact with diatomaceous earth, dehydrate and die. Best of all, they cannot develop resistance to this type of organic pest control. To kill eggs, dust it on your leaves (top and bottom) for spider mites, and sprinkle it over the top layer of your soil for fungus gnats.
  • Moisture retention of your soil by holding water extremely well. It also takes much longer to dry. We do not recommend using diatomaceous earth in large quantities with our Just Cannabis soil, as the soil already has incredible water retention properties.
  • Diatomaceous earth improves plant stability by freeing up nutrients so that they are available to the plant, as it needs them.

Sea of Green


NB! This is not the same as a ScrOG. We will get to that.

The concept of growing several small cannabis plants (as opposed to fewer and larger plants) is often referred to as a “sea of green”. The plants are all kept relatively small and at the same general height, creating the aesthetic impression of a green canopy.

The general pot size used with a ‘sea of green’ setup is around 15cm, or 4 to 6 liters. The plants will usually be fully mature when they reach a height of approximately 30 – 50cm.

The grower will often trim his cannabis plants using the ‘lollipop’ technique. In a nutshell, this means that all the bud sights and smaller colas on the cannabis plant under a certain height are removed from the plant, creating a lollipop effect. This allows all of the remaining bud sights enough exposure to the light from above.

The motivation behind this method of cultivation is that the grower can harvest his or her cannabis plant more quickly. The plant is not required to grow very big; therefor the vegetative phase can be shortened by a few weeks.

A sea of green does not produce a greater yield than other methods of growing; it simply allows the grower to harvest his or her yield faster.

Deciding on which method to use is completely based on personal preference.

Below we have listed some of the advantages and disadvantages of a SOG.



  • Good yields
  • Easier to grow various strains simultaneously (but stick to either indicas or sativas)
  • Quick to harvest
  • Minimal time spent training your plants
  • Best method to maximize limited space (especially when vertical space is limited)
  • Best suited for indicas (sativas can grow to be tall and lanky)



  • Depending on your setup, it may be difficult to access plants further back in your grow area without having to move them around.
  • Keeping the ‘sea of green’ at a relatively even height may prove to be difficult, especially if you’re growing more than one strain. This will create conflict in deciding how high or low to hang your grow lights.
  • Pests and pathogens can spread easily and quickly.
  • If you are legally limited with regards to the number of plants you may cultivate, then this may not be the method for you.
  • Powdery mildew and mold are real concerns when plants are crammed too close together; make sure you have a strong fan with great circulation.



The term ‘SCROG’ is a sort of an acronym with a twist: SCReen Of Green.

The ‘screen’ refers to the mesh that is used to manipulate the growth of the cannabis plant in a horizontal direction (as opposed to vertically up towards the light). Growers make use of cropping, super cropping, topping and mainlining to manipulate the growth of plant into a blanket-like structure, guided by the grower’s choice of ‘mesh’.

Ready-made manufactured mesh is available in different shapes and sizes, and they’re usually made of nylon, plastic or metal. Some growers use fishing net or chicken wire as a mesh. Most growers build their own mesh using materials such as hemp ropes, wire, washing line, bamboo, etc. (This is another area of growing cannabis where you can get creative; find what best suits your unique grow spot!)

As opposed to the ‘sea of green’ method, your cannabis plants should not be placed close together. They will need a lot more space to ‘spread out’ as they grow. The point of growing with a SCROG is to harvest maximum yields from minimal plants.

The height of the mesh will depend on the strain being grown. Sativa strains tend to grow taller than indica strains, and will need more height between the base of the plant and the mesh.

Once the cannabis plant reaches the grower’s desired height, the main growth points need to be ‘topped’ or ‘fimmed’ (Fuck I MissED). This way, the plant is forced to split and grow sideways.

All the shoots growing above the mesh need to be woven into the net as they grow. Longer shoots may need to be tied to the net with plant ties. This is how the grower creates a blanket-like structure of bud sights; each bud sight equally exposed to the light. The result is many buds of equal quality and size.

All the shoots growing below the mesh need to be pruned, so that the plant may focus its energy on the shoots and bud sights above the mesh.

Once in flower, the branches and leaves below the mesh need to be trimmed so as to allow circulation between the buds. A sea of buds will grow vertically up through the mesh, and you will want to prevent mold and mildew by keeping your airflow constant.

A SCROG grow generally takes a few weeks longer than other methods, such as ‘sea of green’. The reward however, is a significantly greater yield. Practice makes perfect with this one, so expect to get better as you go.

Deciding on which method to use is completely based on personal preference.

Below we have listed some of the advantages and disadvantages of a SCROG.



  • Produces consistent, high quality buds.
  • Few plants can yield loads of bud. In areas where growers have legal limitations on the number of plants they can grow, this is an obvious choice. Growers report up to a 20% increase in yield when growing with a SCROG.
  • Ideal for grow spaces with height limitations.



  • Indica and sativa strains cannot be easily grown in the same mesh due to differences in height.
  • The vegetative phase takes approximately three weeks longer.
  • Does not work well with auto-flowering strains.



Cannabis seeds are generally divided into three categories: regular seeds, feminized seeds and auto flowering seeds.


  • Regular seeds are produced when cannabis plants are naturally pollenated, or when regular breeding techniques are used.

They have a 50/50 chance of being male or female; the only way to tell their sex is to grow them out. Male seeds grow up to be male cannabis plants, and male cannabis plants produce no bud. Unless you are breeding your own genetics, you want to get rid of the male ASAP. A male cannabis plant will pollenate all of your female plants (as well as your neighbor’s), so it is imperative that you remove and bag that guy as soon as you’ve identified him!

We’re only interested in the ladies.

  • Feminized seeds are guaranteed to be female cannabis plants. Female cannabis plants produce the flowers or buds, which hold the majority of the plant's medicinal properties.

Feminized seeds are created in various ways. One method is to stress out a healthy female plant during its flowering stage by interrupting its light cycle. Another method is to spray the female plant with a mixture of colloidal silver. The silver solution obstructs ethylene production; ethylene being a hormone involved in flowering. The result is a female plant that produces male buds with pollen sacs. The genetics carried by these pollen sacs are all female, owing to the fact that they are developed on a genetically female plant. When those flowers then pollenate another plant, they produce feminized seeds.

  • Auto flowering seeds are different from photoperiod seeds in that they automatically begin to flower when the cannabis plant reaches a certain size or stage of development.

Cannabis indica or Cannabis sativa strains are crossed with Cannabis ruderalis strains, creating auto flowering varieties. Ruderalis plants are native to Russia, and only grow up to 60cm due to the cold.

Most auto flowering strains grow from seed to harvest in less than 10 weeks. They are more resistant to colder temperatures, and they can be grown outdoors all year round.

While this may sound amazing, they do have their disadvantages. They generally tend to be much smaller and lower yielding than photoperiod seeds. They’re also a bit sensitive; practice makes perfect when it comes to growing auto flowering cannabis seeds.

Grow Lights


When referring to indoor cannabis growing, there are three different types of grow lights that we consider.


  • Fluorescent Grow Lights

Compact Fluorescent Lights (or CFLs) are super cheap and can be found at any hardware store. They are suitable for very small grow spaces, or if you are only planning to grow only one plant. Although they produce a great spectrum for growing cannabis, do not expect any miracles when relying solely on CFLs.

T5 Grow Lights are usually bigger than CFLs, and they’re generally built into a panel or a fitting. They don’t give off a lot of heat, so your cannabis plants wont burn if kept near to them. They also don’t use a lot of electricity.

While some growers experience success in growing cannabis full term with fluorescent lights, we only use them for clones, seedlings and young plants. #TeamGavita all the way.


  • High Intensity Discharge (HID) Grow Lights

HID grow lights are much more effective than fluorescent lights. They tend to get very hot, however, and are often connected to an extractor fan or an exhaust to vent the heat out. There are three different types of HIDs.

  1. Metal Halide (MH) Grow Lights give off a bluish light, which cannabis plants enjoy particularly during the vegetative phase.
  2. High Pressure Sodium (HPS) Grow Lights produce a yellowish light, which cannabis plants enjoy particularly during the flowering phase as it stimulates bud production. Research shows that using HPS lights during the flowering phase produces greater yields per watt of electricity than any other light available. #TeamGavita all the way.
  3. Ceramic Metal Halide (CMH) Grow Lights are also known as Light Emitting Ceramic (LEC) Grow Lights. This is a type of HID involving a metal halide bulb using ceramic as part of the lamp.


  • Light Emitting Diode (LED) Grow Lights

LED lights often come with built-in cooling, even though they run much cooler than HIDs. They are simple to set up; plug and play at its finest! The biggest downside to using LEDs is that there needs to be quite some distance between the plants and the light, which means LEDs are not viable if you have limited vertical space in your grow area.

Strain Names


Every day there are new strain names popping up, with more and more people claiming to be ‘breeders’.

In more recent years there has been a trend in naming strains after their flavor profiles or aromatic qualities, contributing to marketing appeal and ‘hype’.

For the newbie cannabis enthusiast, the strain names can be both confusing and misleading.

The reality is that the manner in which a specific strain of cannabis is grown and processed contributes greatly to the final product. Simply put, let’s pretend that two people grew the same Purple Haze strain in two different locations, using two different grow methods. The composition of terpenes and cannabinoids in the final products of the two respective grows can end up being drastically different. For this reason, strain names alone cannot be relied on for medicinal purposes. TEST YOUR WEED if you want to know what’s in it. Recreational puffing is one thing (and that’s what we specialize in), but making medicine from cannabis is serious business and requires serious know-how.

The name of a strain, however, can give you some kind of general idea of what to expect with regards to flavor and effect.

In obvious cases, the strain name will hint at the flavor profile or aroma of the bud. ‘Sour Diesel’, for example, has a strong, gas-like taste. ‘Strawberry Cough’ smells intensely of strawberries. You get the point.

The word ‘Haze’ in ‘Neville’s Haze, Super Lemon Haze or Amnesia Haze’ would insinuate a more cerebral effect, implying a sativa dominance. The word ‘Kush’ in ‘Afghan Kush, Purple Kush or OG Kush’ would imply an indica dominance.

‘Indica’ and ‘sativa’ refer to different types (or species) of cannabis plants. Below is a list of the four types of weed plants.

  • Sativa plants grow taller, skinnier, and more slowly than indica plants. Their leaves are thin, and their buds are airy and light. The dominant effect of sativa cannabis plants when consumed is more cerebral or ‘of the head’. Users feel buzzed, thoughtful, creative, etc.
  • Indica plants are shorter, fatter, and faster growing than sativa plants. Their leaves are fat, and their buds are heavy and dense. The dominant effect of indica cannabis plants is more of a ‘body high’. Users feel physically relaxed, heavy, weighted down, or ‘couch-locked’ - as we like to say.
  • Hybrid plants are blends of indicas and sativas, resulting in a more balanced effect on the user. A vast majority of the strains we grow and smoke today are hybrid strains.
  • Hemp is also part of the cannabis family, but different in that it contains fokol THC (less than 0.3%). This makes it incredibly unappealing to us as recreational cannabis users, but hemp is one of nature’s most amazing resources. The use of hemp could quite literally change the world as we know it - if some important people started caring. Hemp can be used to create biofuel, plastics, textiles, clothing, shoes, industrial materials (like flooring, roofing, insulation, bricks and hemp concrete), food and paper. Read that again. Ask your government why they’re not doing the responsible thing; investing in hemp farms.


If we serve the plant, she will serve us too.

Grow Bags or Plastic Pots?


Cannabis users all over the world over are making the shift from conventional plastic pots to fabric grow bags.

Plastic pots are strong and lightweight; they are an excellent choice for plants that enjoy a moisture rich substrate, or for plants that are watered infrequently by their tender.

Here at Just Cannabis, however, we grow solely in grow bags or grow boxes. While grow boxes remain our absolute favorite, below we will discuss why grow bags are preferred to plastic pots amongst cannabis growers today. (For more information on grow boxes and an awesome video tutorial on how to make them, please see the section on grow boxes.)



  • In plastic pots, the roots of your cannabis plant can become constricted leading to less water or nutrient uptake. When the roots are growing and they reach the sides of the plastic pot, they begin encircling the pot in search of nutrients and water. In some cases the roots can continue to grow until the pot is filled to capacity, or ‘root-bound’. Fabric grow bags prevent this from occurring, and encourage air pruning and more fibrous root growth. Instead of growing more vigorously and disrupting the structural growth of the plant, the roots understand that they have reached their growth limit when they reach the sides of the grow bag and sense the dry soil and air exposure. Contrary to popular belief; an overgrown root system is not a healthy one.
  • Grow bags are more breathable than plastic pots and allow heat to escape from the soil. Hot roots are unhappy roots.
  • Storing fabric grow bags is easier and more discreet than conventional plastic pots. They are more versatile and take up minimal space. They often have handles, making them easier to move around.
  • The fabric used to make grow bags is porous, allowing water to drain much more efficiently than in plastic pots. This means that your cannabis plant’s roots will dry more thoroughly between watering, minimalizing the chance of root rot. It is much harder to overwater your cannabis plant if it’s in a fabric grow bag, because the water can run out in any direction.
  • Many grow bags manufactured these days are biodegradable, and are made from 100% recycled plastic. That’s sexier than a plastic pot any day of the week!

Grow Boxes: Our Speciality.

A grow box (or earth box planter) is a self-watering plastic box with a built in reservoir. The outcome is that your cannabis plants are irrigated for a few days at a time with minimal effort, while maintaining the ideal moisture content in your soil at all times. The risk of weeds is reduced, and pest management is significantly easier (always use a mulch cover).

Watch this awesome Just Cannabis tutorial video on how to make your own grow box:




White powdery mildew, more commonly known as PM, is a fungal disease which grows and spreads rapidly.

On a living host it reproduces both sexually and asexually. It spreads by releasing spores which settle elsewhere, where they continue to grow and reproduce. Powdery mildew can slow down the growth of your cannabis plant, and in severe instances it can kill your plant entirely.


Identifying PM during the early stages is not difficult to do - for the vigilant grower.

The white, fluffy, spongey, fuzzy fungus stands out again the green of the cannabis plant's leaves. Once identified, the powdery mildew needs to be dealt with thoroughly and with great care; so as to prevent the spreading of the spores.


Powdery mildew is best prevented by controlling the environmental factors which cause it to develop:

  • PM thrives in areas of high humidity and moisture. Growers living in areas of high humidity can make use of dehumidifiers to keep the moisture levels of the grow area at an optimal 40 - 60 % RH.
  • Poor airflow and circulation will encourage the spores to settle and grow. Make sure you are using decent fans to keep the air moving in your grow area. Spores can often settle in fans and ventilation systems; be sure to clean those regularly too. Many growers clean and disinfect their grow areas entirely between harvests. A clean grow is a happy grow.
  • Good ventilation allows fresh air to enter and old air to leave. Without proper ventilation, PM spores will spread easily around the grow area as they remain in circulation.
  • When plants are spaced too closely together, their leaves touch one another creating a moist spot for powdery mildew to develop. Pruning and trimming bushy plants greatly assists in keeping PM at bay.


Once powdery mildew is identified in your grow area, it must be dealt with immediately and with great care. The spores from PM travel easily when disturbed, making cross contamination the most challenging part of dealing with powdery mildew.

The following are organic measures, which should collectively assist in getting rid of your fungus gnat infestation.

  • If possible, physically remove the leaves with the worst PM infestation.
  • Using a damp paper towel, wipe the PM off of the remaining leaves. Do not use the same paper towel to wipe two different areas. Be careful also not to shake the leaves; causing the spores to fall and travel.
  • Using a foliar spray of your choice, coat your cannabis plant thoroughly. Our favourite foliar spray for PM is a mixture of water and 35% food grade hydrogen peroxide. It is organic, safe enough to use daily, and it kills PM on contact! Other popular options for folia sprays are solutions containing water mixed with either milk, alcohol, bicarbonate of soda or neem oil.
  • Revisit the 'prevention' section and ensure that you are creating an environment which is non-conducive to a powdery mildew infestation. Air flow and ventilation are key to keeping PM at bay.


Germinating Seeds


There are many ways to skin a cat. Germinating cannabis seeds is no different.

Here at Just Cannabis we only make use of Jiffy pellets, seed trays or small pots of Just Cannabis soil - with the moisture content juuuust right.

We are not fans of the 'germinating-in-tissue-and-replanting' method. We're not saying it can't be done; we're saying it's very 'finicky' and requires some attention that we'd rather direct towards smoking our bud.

The time frame is of monumental importance when germinating cannabis seeds in wet tissue; the moment that the cotyledons appear it means you have possibly let it go on too late. Also, the longer that the teeny-tiny little taproot is exposed to air, the more likely it is to suffer damage. A newly sprouted cannabis seedling is vulnerable and sensitive, like a human foetus that should still be inside it's mother's tummy. You wouldn't handle a human foetus, would you? All in all, we prefer to let nature do it's thing. (This is a common theme with us, you see). Nature knows what to do with that seed. Nature knows that the seed wants a dark, damp bed to sleep in so that it can figure out up from down. It's hard letting your babies grow up without being a smothering and over-involved parent, but somehow we get through it.

The goal is to maintain the germination medium at about 20-28ºC, and at 70% relative humidity. Lower temperatures and humidity ​​will result in a slower and less successful germination, while higher ones ​​can bring challenges with rot and fungus.

Always try to plant the seed with the tip down, and the crown facing up towards the sky. (The crown is the fattened side with the 'crater' in it). The crown of the seed acts as a kind of hinge when the seed germinates, and allows the tap root to exit out of the opened tip. and grow straight down. If you plant your seeds upside-down you might run the risk of the taproot growing upwards, in which case your seedling will die. You don't, however, need to fret about getting it precisely upright. Again we want to remind you that nature has a funny way of knowing her way around.

Planting your seeds too shallow or too deep can also have detrimental effects. Too shallow and the stem will weaken and break; too deep and the seedling may never emerge. We experience a depth of 1 - 2cm to be just right.


Use a seed tray or small pot, and fill with Just Cannabis soil. Level off and firm lightly. Never compress the soil. Water thoroughly using a watering can with a fine spray, and allow to drain. Make a small hole in the medium of approximately 1 - 2cm in depth, and carefully place the cannabis seed in the hole. Keep the soil moist, but be careful not to overwater – especially during the early stages immediately after germination. Once the seedlings have rooted successfully, remove the root ball from the seed tray or small pot, and transplant into the final container.


Soak the jiffy pellets in lukewarm water, or as per manufacturer's instructions. Ensure that the jiffy bag is not overly wet; we prefer to squeeze the jiffy softly around the sides and from the bottom to get rid of excess water. Make a small hole in the medium of approximately 1 - 2cm in depth, and carefully place the cannabis seed in the hole. Cover it up. Some Jiffy trays come with a plastic dome which should be opened for a few minutes twice a day. Once the seedlings have sprouted, remove the plastic dome.

Low Stress Training


Low stress training involves the bending of young and supple stems downwards and away from the middle of the cannabis plant, causing them to grow flatter and wider.

LST involves the process of bending the tallest stems down as the plant grows, allowing all bud sights maximum exposure to light from above. Bent wire hooks or plant-ties can be used to pin or secure the stems into place.

This method of plant training is considered 'low stress', as the plant is manipulated gently as it grows without causing sudden damage or disruption to her.

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