With the rise of cannabis cultivation, and after receiving so many questions from people starting to grow cannabis indoors and not getting the results they expected, we felt compelled to make some general recommendations to new growers based on our experience growing with some prominent commercial growers. By following these tips you will achieve a quality crop with no unforeseen events.
#1 Always remember safety is the top priority
There are three key safety risks anticipated from growing indoor: 1) electrical and fire hazards; 2) inappropriate use of pesticides and fertilizers; 3) water damage. These risks may be present during cannabis cultivation, harvesting, and handling, and as a result, there may be concomitant existence of each of these types of risks.
Fires are a major concern because improper wiring of lights and fans can cause a short circuit. This is particularly likely if the electricity is installed by amateurs who tamper with the cabinet circuit. The indoor grower should carefully avoid tampering with the circuit board or using terminal blocks, and make sure that all cables are cut to the correct size. Buy only reputable brands and always place equipment away from a water tap or tank to avoid accidents. Remember that fires caused by an indoor cannabis garden won't be covered by insurance.
Cannabis cultivation can be affected by a number of pests, including moulds, blights and insects that attack living plants, and fungi that attack dead plants during drying or curing. Due to the time and cost required to complete a full cannabis cultivation cycle, growers may adopt risky pest control practices to avoid crop loss. Although current PMRA-approved products are generally considered low-risk, novice growers should strictly follow product label instructions, especially regarding general indoor use precautions. In addition, most fertilisers can be extremely irritating to the eyes, mouth or open wounds. To prevent harm, always read the instructions and learn what to do in the event of an accident. Most of the time it's just a matter of common sense. For example, using protective equipment such as gloves or goggles minimises the risk of injury.
Water damage is another potential problem, as a water tank could overflow - especially if you are growing hydroponically. In addition, a constantly damp room can cause the floor to rot and the cement to become porous. In the worst case, mould can grow and wreak havoc on the crop or the grower's health. The best way to reduce the risk of water-related problems is to waterproof the floor and walls of the growroom. This will create a moisture-free environment, making it much easier to care for your plants. Don't forget to turn off the tap to prevent flooding. Better still, place the water tank in the shower to reduce the risk.
#2 Choose a good genetics for cannabis cultivation
Good genetics is essential to achieve a good harvest. Good genetics is the one that in addition to producing good cannabis, adapts to your level of knowledge as a grower. There are currently many seed banks that offer a wide range of varieties among regular, auto-flowering and feminized seeds.
Remember: Only female plants will produce buds. You can make sure to have female plants by using feminized seeds.
For indoor novice growers, we recommend first-generation hybrids, which tend to give fewer problems with pests and nutrition.
Indica hybrids. The easiest cannabis cultivation varieties to grow indoors are, for example, the Critical Bilbo, ready in just 50 days to 12 hours of daylight daily. Another suitable variety for the first crops is the White Widow, although it takes 60 days to bloom, it is resistant to most pests and is difficult to overfertilize (one of the most frequent mistakes in new growers).
For larger growing rooms, Indian phenotypes have the advantage of being easy to a manicure and need less pruning during their growth. In addition, having short flowering cycles of only 8 weeks, pests have little time to settle in plants and with a few preventive treatments is usually enough to control them. Some of the most cultivated varieties are Industrial Plant or Afghan Kush xBlack Domina.
Sativa hybrid. Once you have a few plants, you will want to try new varieties, so you can start by choosing hybrids with more Sativa genetics. Sativa hybrids take longer to flower, so there is a higher risk of pests (simply because they spend more time in the growroom). However, they offer a wider range of flavours and are different from what we are used to seeing in cannabis grow clubs. We suggest you try White Russian varieties from Serious Seeds or High Level from EVA Seeds, which will surprise you with their high production, taste and smell. Sativas delight us with a more stimulating and less narcotic effect than most commercially grown strains.
Sativa. For advanced growers who want to try something special, we recommend these varieties of Cannabis Sativa. The more sativa strains have a greater commercial value as they require a lot of hand work and finesse to grow, but they can surprise us when grown well. Some strains can flower (and stretch!) for three months indoors, and not all of us are trained to grow them properly. Our favourites include Greenhouse's Jack Herer and Serious Seeds' Kali Mist, both of which have won numerous awards. Many professionals in the industry consider these types of plants to be the best varieties of cannabis. Before planting a strain of Cannabis Sativa in our nursery, we always ask how many weeks it takes to finish flowering to avoid any surprises.
Indica. Currently, the trend in social clubs of cannabis is the present elite of the kush family ( kush strains ). These plants are entering strongly from Canada and the United States, where their cultivation was already perfected a few years ago, and it seems that they are the new fashion among the most advanced growers.
Indica cannabis usually consumes little water and also requires a poorer fertilization program than first and second-generation hybrids. Many people fail with this type of seeds, being accustomed to hybrids that consume large amounts of water and nutrients. It is advisable to grow them with organic fertilizer at half the dose of the recommended one.
Some of our customer’s favorite Indian cannabis strains are OG Grape, KryptandReCon, from DNA Genetics. These plants have great power and their flavor is very intense, with acidic touches that sometimes remind us of pine resin. Normally the productions they offer are medium and also their cultivation demands greater expertise.
#3 Decide your culture substrate and fertilizer
There are several mainstream substrates for growing cannabis, including a wide range of peat-based grow media and black or inert hydroponic substrates such as coconut, arlita, mapito or rockwool. Each substrate has different characteristics, and the grower should always choose the one that is best suited to his crop. For example, there are substrates with added fertiliser and perlite, which allow excellent oxygenation of the root system and are currently very successful in indoor cannabis cultivation. Solid additives, such as worm humus or guano, are additives that improve the physico-chemical properties of the soil, as they contain nutrients and organic matter, creating a suitable environment for the development of cannabis plants.
Anyway, if you are not prepared to have a thorough understanding of various substrates, you can start growing with organic soil because it will also give you better results.
Beginners are always better off starting with organic fertiliser. The natural, organic cannabis fertiliser, made with nutrients derived from living materials such as algae or natural plant extracts without chemical components, is the best choice for most foodies. They are fertilisers designed for organic soil substrates or for growers who prefer a crop of excellent quality over abundant production. The 100% organic buds have more flavour and aroma than other fertilisers. Organic fertilizers contain carbon particles that, when in contact with the soil, are released by the fungi in the substrate, providing nutrients to the plant.
Initially, organic soils have sufficient nutrients for the initial development of the plant, so we recommend waiting 2 weeks after transplanting before applying the first fertiliser. It is important to remember that organic fertilisers take between 7 and 10 days to take effect and show results. Natural fertilisers also have a very good pH regulation, which makes the grower's job easier as there is no need to worry about the pH of the water during the growing period.
#4 Choose the right cultivation equipment for cannabis cultivation
When creating an indoor cultivation room, selecting the right equipment at the start is crucial to success.
First, sizing your systems for cannabis cultivation.
Due to the high heat load and water content associated with a garden, sizing systems for cannabis cultivation can be very different from sizing systems for other environments. For example, it is better for beginners to calculate the dehumidification load of a cannabis garden to be at least five gallons per lamp per day. If you are unsure of how to size a system correctly, always consult someone who knows more than you do, such as engineers who specialise in sizing cannabis cultivation equipment.
Another important factor in determining the size of your operation is your budget, working out what equipment you can buy for that money and then deciding how big a garden you can build within that budget. It is important to note that "working out what equipment you can buy" does not mean looking at the cheapest equipment and making decisions based on that information. Instead, your yield goals and monthly expenses should be considered. Energy efficient equipment is critical to the bottom line of your equipment portfolio and should be considered from the outset. By spending a little more at the outset to buy good equipment, you'll save time and money down the line, resulting in more profit.
Then, buy them.
Ventilation System: Choose an open ventilation system that uses carbon exhaust filters to control orders for the best airflow in your indoor grow operation.
pH and TDS Measuring Equipment: Getting accurate pH and TDS measurements quickly and frequently are key to keeping an eye on the development of your cannabis plants. Choose measuring equipment that is accurate and doesn’t require frequent calibration, which can slow down operations or result in inaccurate readings.
Indoor Plant Lighting: Indoor cannabis growers have many different options when it comes to lighting. Your choice of lighting option will largely depend on the electricity rates in your area and the layout of your indoor grow set-up. Although HPS lamps have been used in cannabis cultivation for a long time, LED grow lights with a much better spectral composition, up to 50% higher energy efficiency and 5 times longer lifetime are definitely more affordable in the long run than HPS.
Temperature Control: HVAC equipment is extremely important to keep your plants at the proper temperature. As stated above, your choice of lighting could increase cooling costs. For greenhouses, this will especially require a very precise temperature control system.
Humidity Control: Not only do your plants need the proper humidity to reach their full potential but having the wrong environment could lead to the growth of mold which could ruin your entire grow.
CO2 Generators:Adding CO2 Carbon dioxide (CO2) is one of the most underestimated aspects of an indoor garden. Plants need CO2 to grow, and without sufficient levels their growth will stall. Adding CO2 is also one of the cheapest ways to boost production and increase yields. In sealed grow rooms, it is essential to add CO2 to provide your plants with a constant supply. Growers should supplement with CO2 to stimulate photosynthesis and improve plant growth. CO2 uptake and assimilation are closely linked to light and temperature. The recommended CO2 enrichment level is around 1200 to 1500 ppm.
Trimming Equipment: Trimming can often be a bottleneck for commercial grow operations. Using commercial trimming equipment can help make the trimming process more efficient.
Gloves: For any employees handling your cannabis plants, gloves are a must for the protection of your workers and your grow. A cannabis industry study found that 18% of cannabis growers report skin irritation. Bacteria from your hands can also affect your plant health.
Antibacterials: Another way to prevent bacteria from infecting your grow is to set up wash stations with antibacterial soap or gel.
Magnifying Glass: Being able to see your cannabis is crucial for determining the quality and potency of your cannabis cultivation. Having a magnifying glass with LEDs is also very useful for spotting contaminants such as mold, mildew, hair, and bugs.
Eye Protection: Protect your eyes from harmful particles and vapors that are present during the cannabis growing process. Eye protection is especially important for anyone working with chemicals that could cause damage or irritation to the eyes.
Pesticide: Pests can be a major problem for cannabis cultivators. However, before using any chemicals to treat your plants, make sure you understand the federal and state legislation for using pesticides for cannabis plants in your state.
#5 Water your plants in the right way
Watering in cannabis cultivation is one of the most common operations, both in indoor and outdoor cultivation, so it is worth reviewing four basic concepts to get it right and get better results.
What kind of water?
Before you start planting, you should know what water you have available. In some areas, tap water is not suitable for the correct growth of cannabis. In this case, you can resort to bottles of bottled water or reverse osmosis devices (depending on the size of your crop).
How often?
There are a number of variables that make us water more often or less:
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Large plants need more water than small plants.
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Low relative humidity causes plants to need more water.
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More heat means more need for water.
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A flowering plant needs more water than a growing plant.
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A large potted plant takes longer to dry than a small potted plant.
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Flood irrigation is less frequent than normal irrigation (by gravity).
As a general rule, in an interior, it is watered every two or three days, if we water manually. Another story is the automatic irrigation systems with irrigation pumps and drippers, which usually give several waterings a day, but with little water volume.
To know if we have to water the plant, it is best to weigh a pot and look at the top layer of soil. We have to get used to the weight of the substrate in field capacity, to know:
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Let's water little by little until it starts to drain water from the bottom.
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Let the excess water drain for about thirty minutes, without any plate or tray underneath.
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Weigh the pot, and we stay with the idea. From now on we want the plant to have more or less this amount of water always.
Now we will have to look at how long it takes the plants to lose water and dry a little, but not weigh very little
How much?
As an approximate idea, we can water a square meter indoors with about 10 or 15 liters. It will vary depending on what we have said before: plant size, stage, relative humidity, temperature ...
We recommend watering with between 10 and 20% of the volume of water with respect to the substrate:
In 5-liter pots indoors, a plant can be irrigated with half a liter or a liter of water at most.
But it is best to do what we have explained before, water the plants well and remember the weight of the pots. From there we will water so they always stay that way, with the same weight.
Pay attention to pH and EC
The acidity of the water/nutrient mixture is essential for the proper development of cannabis. Normally it is necessary to acquire a lower pH fire to maintain the pH values between 5.8 and 6.3. Electrical conductivity is a measure of the concentration of salts in the water. An excess of fertiliser will slow down growth, while a lack of it will cause deficiencies. The ideal water for irrigating plants should have an initial EC as low as possible, and fertilisers are added until they reach values of 2 or 3 ms/cm, depending on the variety and the stage of the cannabis plant.
#6 Install the grow lights according to the plants' surface.
Do not expect that by putting more plants with the same focus you will get more harvest. Cannabis plants need about 40-50w of LED light per square meter to bloom properly.
Check the PPFD footprint map of the grow light
We know that mature weed plants want 600-800 PPFD to be stimulated. This means that we need to adjust our grow light so that we project this intensity onto our plants. PPFD levels can be regulated with distance. As photons spread, the further the distance between plant and light source is, the less intense the light will become as the photons spread sideways, away from the plant.
The general theory behind distance:intensity: the footprint is:
Short or no distance between lamp and plant: high PPFD (light intensity) but the small light footprint (coverage area).
Long-distance, let’s say 2’ (61cm) between lamp and plant: low PPFD but large light footprint.
Take into account the overlapping effect when growing with more than one light
From the design of GLIC650, we have taken into account that instead of concentrating the light output into a small area with very high PPFD, it is more important to provide more even light distribution for commercial growing conditions in which it is very common to install grow lights in the order of a grid. For this reason, the whole optical design of GLIC650 is dedicated to delivering a wider and more even light distribution for enhancing the overlapping effect.
Photoperiod Manipulation
Cannabis, like many plants, matures as the seasons change. As light cycles shorten and light waves lengthen, cannabis plants are stimulated to produce flowers or seeds in preparation for the next generation of plants. This happens naturally outdoors as the summer months come to an end and the days get shorter; as the earth begins to turn away from the sun, different light waves penetrate the atmosphere. When it comes to growing cannabis indoors, growers must carefully manipulate their plant's photoperiod (the amount of light versus hours of darkness) to achieve the same results. While seedlings do well under constant light, vegetative plants should be kept under a light cycle of no less than 18 hours of light. While some growers keep their vegetative plants under constant light, it is believed that the healthiest and most prolific plants receive at least a few hours of darkness in a 24-hour period. To signal a cannabis plant to flower, the light cycle needs to be changed to 12 hours of light and 12 hours of darkness - no more, no less. The easiest way to do this is with simple timers that can be plugged in between the light source and the power source. These timers can be set to switch on and off at the same time each day to reduce the chance of growers making mistakes.
Please note that cannabis plants are very sensitive to light and must never be interrupted with light during dark hours. We suggest programming lights to turn on during regular daylight hours (when you’re most likely to be tending to them) and off during the hours that you will not need to access them. If you ever do need to view your plants during dark hours, use green lights only.
What about auto-flowering strains?
In recent years, cannabis seedbanks and breeders have developed “auto-flowering strains.” These strains contain genetics from Cannabis ruderalis, a unique cannabis cultivation variety discovered in Siberia that flowers based on age, rather than photoperiod.
Unlike regular cannabis strains, auto-flowering strains will flower after a certain amount of time regardless of the lighting cycle. If you start early in the season you can already harvest your first crop after 7-8 weeks. Just take care you're ready for round two.
#7 Tender you plants carefully as it grows
Ventilate your room
Plants need a continuous supply of fresh air to grow and flourish. If we do not renew the air in the room, the carbon dioxide supply runs out, and the plants stop growing.
Prune your plants
Indoor cultivation is characterized by obtaining buds of good caliber at the top of the plant, while lower branches tend to give less quality. Good pruning will improve the volume and quality of the crop.
Good pruning will improve the volume and quality of the crop.
Watch the pests
Indoor cultivation occurs in a sterile environment, in which there is no natural enemy of pests that attack cannabis cultivation. To avoid unwanted attacks, you have to be aware of the plants and act after detecting the first symptom.
Control the size of the plants
You have to take into account the maximum height at which you raise the focus and the minimum distance between the bulb and the tip of the plants. If we go with the growth, we will have problems in flowering, since the plants stretch a lot. In order not to run the risk of burning the tips, it is better to control the height already during the growth phase.
Watch the humidity
The relative humidity is decisive to ensure good flowering. Too much moisture causes fungi to appear. Very low humidity has an impact on development. We recommend that you keep a value close to 50% during the flowering phase.
Control the temperature
As with humidity, the temperature is decisive to achieve success in cultivation. You can adjust it with an air conditioner or with ventilation. The optimum value for most varieties is around 25 ° C, both in growth and flowering.
Keep it clean
A cultivation room must be impeccable: no dust, no dead leaves or substrate remains in the soil. The cleaner you are, the fewer pests will appear in culture.
Wash the roots
The plant will need to eliminate the possible accumulated salts in the substrate, especially if you have grown with a range of mineral fertilizers. There are numerous products for this purpose, which make the plant yellow, the first symptom that the roots have been washed.
#8 Practices at the cannabis flowering stage
Your cannabis plants have been in the vegetative stage for some time. They have grown in size, developed a strong structure and many fan leaves. When the female plants produce small white pistils from the nodal areas, this signals that it's time for the flowering phase. During this phase the buds grow and develop a solid cannabinoid and terpene profile. You need to start the flowering phase by changing the light cycle from 18-6 to 12-12 hours of light and darkness. Before we go into detail, it's important to note that the biggest mistake growers make during the flowering phase is overfeeding. Just because buds are forming doesn't mean they need to be bombarded with fertiliser and boosters; this often leads to nutrient toxicity. As a rule of thumb, fewer nutrients give better results. If a nutrient deficiency is detected, the necessary compounds should be added gradually.
The entire flowering stage will be about 8 weeks and consists of the following stages: Pre-flowering, Early flowering, Peak flowering, Late flowering - Maturation stage.
Stage 1: Pre-flowering
Usually the flowering phase is considered to be a single stage, but there are certain nuances that are valuable to distinguish for best results. When the white pistils (hairs) begin to appear in the nodal areas, the pre-flowering stage has begun. At this point, indoor growers switch the light cycle to 12-12, which signals to the plants that the autumn season has begun and it's time to develop flowers. It's important to continue with regular vegetable feeding, then gradually switch to the P-K (phosphorus and potassium) side to allow the buds to grow and mature.
Novice growers often switch completely from vegetative nitrogen-rich fertilisers to P-K-heavy fertilisers, which is often a disaster. At this stage the buds are barely formed and require only trace amounts of nutrients. During the pre-flowering stage, the nodal areas will develop more pistils and larger calyxes (cannabis cultivation flowers), leading to the next stage.
Stage 2: Early flowering
The calyxes are growing in size and the pistils are becoming longer. This is the early flowering stage. The buds resemble round balls with white spines. At this point, the plants are still growing in size and can stretch significantly depending on the strain's genetics. The buds will require slightly more P-K at this stage. If possible, the temperatures should be slightly lowered to around 23°C during the light hours. This will signal to the plants that we’re further into the fall season.
Stage 3. Peak flowering
Peak flowering begins when the bud sites merge to form a long cluster of green calyxes and white pistils. At this stage the plants should receive higher levels of P-K as the buds are now increasing significantly in size. This is the stage where growers need to be extremely careful with environmental conditions and feeding. The buds are starting to suck the soil dry and are full of water, so it's logical that more water is needed. The best way to do this is to simply feel the soil. If the soil dries out, the watering schedule needs to be adjusted. If something goes wrong at the height of flowering, the buds won't grow much. So be careful.
Stage 4. Late flowering - Maturation stage
Finally! Buds with substance. White pistils are sticking out in all directions and the buds themselves are getting bigger every day. This is the final stage of the flowering process, the ripening stage. At this point the buds are quite large, dense and heavy. The white pistils begin to curl, turning yellow, orange and then brown. The trichomes change from clear to cloudy and milky. With prolonged infusion, some trichomes will turn amber. For a more uplifting effect, harvest the buds when the trichomes are mostly milky. For a more sedative and narcotic high, wait for some trichomes to turn amber.
At this stage, nutrient levels should be gradually reduced and nitrogen should be virtually eliminated from the mix. 1-2 weeks before harvest, the plants need to be flushed of all nutrients that are not desirable for consumption. This is usually done by soaking the soil with clear, pH-regulated water. This allows the plants to utilise all stored nutrients. After the plants have been rinsed, the leaves will turn yellow and start to fall off - that's a good sign. When the buds are fully ripe, it's time to harvest, which marks the end of the flowering phase.
#9 Cut at the right time
The cannabis harvest cannot be left to chance. There is a time frame, not too long, in which we can harvest our plants. Before that time the herb will be not very psychoactive, while later it will lose organoleptic properties.
To actually see the trichomes you'll need a microscope. Handheld microscopes ranging from 30x to 100x will give a clear view of the colour of the trichomes and can be purchased from any grow supply store. With a microscope in hand, a grower can see the transformation as the plant reaches peak potency. At this stage the trichomes change from clear to an opaque white, from clear to opaque, indicating full maturity. At this point the trichomes are no longer producing any additional THC. Unfortunately, not all trichomes develop at the same rate and you will start to see some amber trichomes before you see a consistent opaque. As soon as the amber trichomes appear, CBN will begin to develop as the THC breaks down due to exposure to oxygen and UV rays. At this point you can assume you've reached maximum THC and your plants are safe to harvest.
#10 Dry and Cure
Drying cannabis is as important as cultivation. After having passed the crop concerned with watering, fertilizing, pruning, treating, etc … we must make a final effort and take care of this stage to the fullest. The wait and the work invested for weeks will only be worth it if we can dry the cannabis cultivation well to begin the curing process and thus be able to taste the tasty buds …
The pre-drying step of female cannabis flowers is a manicure. This process of stripping and cleaning should be done so that all buds end up having a similar size. This facilitates homogeneous drying and will prevent larger buds from passing moisture to smaller ones. The central buds open and separate into medium buds by cutting through the small stems that bind them to the main branch. It is very important to be wearing gloves and good tools such as pruning shears.
At the time of manicuring, the largest leaves that barely contain resin should be separated from the leaves that grow between the buds. The small and medium leaves of the buds stop and can be used for the extraction of hashish once dried. The larger leaves are usually discarded since they contain a lot of chlorophyll and little resin, which gives a very low yield in the extractions. It is also important to clean the scissors from time to time while harvesting, to collect the resin residues of the plants. This work is easier when using a few drops of alcohol.
Mesh drying is recommended for large productions. For this type of drying, we have several models, such as the square dryer mesh and the round dryer mesh. These tools allow a great saving of space in the drying room with respect to the second drying technique.
The meshes have several floors, in which we can sort the buds by size or cutting time. We can also dedicate one or more levels for the material for resin extraction, such as undercooked leaves and buds. Whenever we put buds, we must avoid touching each other, to facilitate the process of drying cannabis.
The relative humidity recommended for drying cannabis is around 30 or 40%. This degree of moisture allows the herb to dry in about 10 days, after which time it will be ready for curing. If your drying room is very wet you have the option of starting a dehumidifier with a tank, to reduce the risk of rot and drying time.
To make sure that moisture pockets do not form, the air flowing through the room must be removed with a small fan, such as the Cyclone floor fan. It is placed in a corner of the room with the flow not directly to the buds, so that it removes the air but does not shake the plants too much.
Another very important factor is temperature. The aroma and taste of cannabis are largely due to molecules called terpenes. These compounds are volatile and are lost by heat. In order not to lose aroma or taste, cannabis should never be dried at more than 25º C.
If we make sure we have good air circulation, we only need to monitor the temperature and relative humidity with a digital thermohygrometer, and regulate the fan and humidifier to adjust them to the desired level.
It is also important that the room is dark so that the molecules that give the herb its properties do not break down. In the presence of light, THC breaks down into less psychoactive forms such as CBN. The presence of this cannabinoid in cannabis samples usually indicates a poor drying or curing process. If you follow all these tips for drying cannabis, after a week or two the buds will be ready to store and start curing (usually when the plant stems start to creak when bent by hand). In terms of curing, it is recommended to store in glass jars or airtight containers. These are perfectly sealed with a lid and there is no exchange of air with the outside environment. This helps to homogenise the moisture content of the plant material inside and to ensure a gradual transformation of the cannabinoids. Once packaged, the herb should be protected from sudden changes in temperature and sunlight. The quality of the product will improve over the weeks and months until it reaches its maximum quality around the year of curing.
Note: The above content is reproduced from VANQ