Chapter 2: Indoor Marijuana Growing

For many people in many climates and environments throughout the world, growing marijuana indoors is the only option they have. Luckily for you, cannabis is a versatile plant that can grow under a many number of conditions. Just be sure that you check with the breeder to ensure where the strain you have is meant to be grown. Unfortunately, some seeds are grown only for indoor use and cannot be grown in the great outdoors.

The obvious first step in growing marijuana is obtaining the seeds and before you go to your trusted agriculturist or anyone you have known selling plant seeds, you have to be conscious that growing marijuana is not legal in all locations. So, learn to be discreet in all actions you will take in order to start growing your marijuana plants. Growing marijuana should not be compared to picking up packages of vegetable or fruit seeds at the grocery store and planting them in your backyard. This requires a lot of cautious steps to take as well as enough and accurate knowledge in growing weeds. There are many factors to consider such as growing indoors or outdoors. How many plants do you want to grow? Are you fully prepared with the responsibility of being a marijuana grower? If so, do you have the funds to finance this venture? If you want to grow marijuana outdoors, do you have a nice and concealed location? Apart from that, you also have to consider the quality of soil as well as the weather in your location. Although marijuana can be grown in any parts of the world, there are certain techniques to be followed depending on the climate of your area as well as many other factors.

This ebook will help you explore as well as come up with the right answers to all your questions about growing marijuana. The next sections will help you understand what you need to do when growing for both indoor and outdoor, the different techniques used depending on the option you choose as well as harvesting and storing your marijuana plants. These and so much more!


Indoor Growing

The first aspect to note when obtaining seeds is they’re meant to be grown indoors or outdoors. This, you should check with the breeder if possible because the last thing that you would want to do is growing marijuana outdoors when it is meant for indoor growing. Many breeders develop seeds that are specifically for outdoor growing, so it is best to ask.

Growing in the right conditions is essential for the best yield. In the right conditions, you can actually harvest a pound per square meter, giving you a lot of kush to play with.


These conditions include: 

  • Temperature
  • Air circulation
  • Humidity
  • General plant care 

The major advantage of growing indoors is that you have greater control over these conditions and can avoid weather extremes and wild animals tearing up your beautiful marijuana. The section below will discuss more of the different advantages in growing marijuana indoors.


Advantages of Growing Indoors

  • Hygienic Environment

Since you have great control of the environment, you can have a clean and hygienic place compared to growing outdoors. For growers who are seeking medical use of their plant, a hygienic place to plant is the most important factor to consider. When marijuana is cultivated with the plan of using it for medicinal purposes, it needs to be free of fungus, parasites, germs or any microscopic organisms that can cause illnesses. People who have sensitive immune systems should only consume products that are free of any insect, pesticide or spore because they’re taking their respiratory allergies into account.

  • Great Control of Climate

When installations have been done in the area you want to cultivate, you will have excellent conditions for growing. This means that all necessary aspects to cultivate indoors has been taken into account such as sufficient light and perfect temperature. This way, the plants are sufficiently nurtured all the time. Growing indoors provides a good quality product and a good profit, unlike outdoor growing which has many worries including storms that can destroy an entire production in just a blink of an eye or periods of drought that dry plants.

  • Multiple Harvest

Outdoor growing may also have benefits too but being at the mercy of the seasons is not one of them, especially if you live in an area with a cold climate. Since cannabis is an annual plant, which means there are a few flowering periods in a year, you may not achieve the maximum amount of harvests if you don’t perfect conditions. If using the right techniques, you can harvest several times per year. Hypothetically, there should be 6 flowering periods per year because it takes 2 months for the plant to mature and flower. With this, you can grow cannabis all year round. You just need 2 rooms for this, one for the flowering phase (12 hours of light) and one for the vegetation phase (18 hours of light).

The plants mature in the flowering room where they get 12 hours of darkness and 12 hours of light. Meanwhile, you can place the cuttings in the growing room to expose them to 6 hours of darkness and 18 hours of light. When doing so, the cuttings will stem and sprout while the plants in the first room matures. Then all you have to do is put a new set of cannabis plants in the flowering room and so on and so forth. In the earlier blooming period, the new set of cannabis plants will cease to grow. Following this technique, you can achieve up to 6 harvests in a year.

  • Growing Marijuana is a Lot of Fun

Indoor cultivation of marijuana is considered as a craft. It takes a lot of work in mastering the different techniques, perfect conditions and all subtleties of indoor growing. However, just like any other crafts, it’s a lot of fun. It can be a very stimulating hobby coupled with wonderful learning experience. Furthermore, if you are using this for medical purposes, you can focus on the cultivation than on your poor health condition.


Despite all the pros of indoor growing, it doesn’t mean that it’s not without problems. The whole operation can be a lot of work, especially from the start when you are still feeling your way through and perfecting the different techniques that you should use. You have to invest time, effort and of course, money. If it isn’t something you are willing to invest in, indoor growing is probably not for you. The expenses can add up quickly plus it’s difficult to set up. You also need to check up on it regularly.

One thing you also have to bear in mind is being careful about the law of growing cannabis. While many countries are legalizing it, it might be illegal for you to setup and cultivate indoors. Protecting yourself and those around you is more important before you even begin.


The correct light set up is essential to your marijuana. Without which, they would wither and die easily. Depending on your country's climate, natural light may not be readily available and so artificial light is a necessity for the photosynthesis process, which is essential for all plant life.

When using lights, be sure to think about conditions such as:

  • Amount of marijuana being grown
  • The space being used
  • Electrical capacity of your growing space

These are essential to keep in mind when you start thinking about your light setup.

After this, you will have to think about what type of light you will use with most users limiting their choices to fluorescents, incandescent, and HID (high-intensity discharge) lamps. In terms of time and cost effectiveness, your best option is to opt for HID lamps, especially during the vegetative and flowering stage. These are sold as Metal Halide (MH) and High Pressure Sodium (HPS) lamps. In my opinion, they are the best for your marijuana plants because they don't require as much electricity as the other options. They’re also brighter and last longer. They may cost more upfront, but will save you money in the long run.

Using Light Effectively

Upon the purchase of HID lamps, whether it be MH or HPS lamps, the setup is critically important. The plants need an even distribution of light to ensure that all plants receive an equal amount of light. If you don't have enough lamps, try to connect them to a tracking system, which is set up so that the lights will move automatically; a technique used by many professionals. This will ensure the plants receive the optimal amount of light with the least amount of actual lights used, which will save cost on lamps and electricity. If you still have problems with light distribution, reflective materials such as lining the walls with aluminum foil or painting the walls white can help with this.

A downside to the HPS lights bulbs is that the light can be too much for the plants, especially during germination, so growers will opt for fluorescent lights during germination as they don't produce a lot of heat and can be lowered closer to the leaves.

One last point to be aware of is the electrical capacity of your location. Personal growers rarely need to worry about this as they might only use a few hundred volts more per hour than usual, whereas large indoor gardens can be a burden on the circuit, especially in older homes that only have 15-amp circuits. Always check your circuit capacity before you create a large set up.


Once you have finished the light set up, it's time to start worrying about the germination process. Germination, essentially, is the coercing of the seed to sprout by providing it with the correct conditions. Without which, the seed would remain a seed.

Luckily, there are many methods you can use to germinate your seeds, and depending on who you talk to, every method is better than the last.

Simply using soil is, in my opinion, the best and most natural way of germinating a seed. Just place the seed 3mm deep and keep the soil moist for roughly 7 days. As simple as it sounds, it has a 75 to 80% success rate, depending on the quality of the seeds, of course.

Germinating Process

Apart from the natural method I recommend, there are other methods such as:

  • The wet paper towel method which has an 80 to 90% success rate; however, it requires a lot of care during the transplanting process as breakages are common.
  • You can also use a “propagation kit”, which is an economical way of saying “growing medium for seeds”. These can include rockwool cubes, which have a similar success rate to the paper towel method.

These methods, however, are not easy, especially for the beginner grower. Both methods require transplanting, which is a difficult process. It can cause the seeds to become “shocked”, which could stunt or kill the growth of the plants completely. This is not necessary in the soil method so try to stick to this.

Germination Soil

Choosing the correct soil may seem like a difficult process, but is really quite simple. The most important thing to keep in mind is:

  • The amount of nitrogen in the soil should be more than the other two nutrients (Phosphorous and Potassium) combined.

This will allow the marijuana seeds to thrive. If you go to garden centers, they will sell soils marked as “germination soils”, but really they are pretty much the same as conventional soils. Just look for soils that have an NPK (Nitrogen-Phosphorous-Potassium) ratio of around 5:1:1 or 8:4:4.


Although the soil is pretty easy to choose, the containers are quite important. Commonly, growers use 2-5 gallon buckets as marijuana root systems are extensive and need room to grow, and so it makes sense to place the seeds in these to begin with. The roots require these large areas to grow and thrive with adequate nutrients and a satisfactory water reserve.

Tip: Smaller containers can be used, but require later transfer, so it doesn't make sense to use these at any stage.


The seeds themselves can take a quite a bit of work and the perfect conditions to eventually spout. The first factor to think of is lights. The plants usually need about 25 to 35 watts per square foot. Although seeds don't need light from the very beginning, it's common for growers to use them to warm the soil; thus, promoting germination and to have them ready right when they sprout. This light will act as their sustenance for a period of time and can affect the quality of the plant later in life.

Positioning of Lights

At this stage, the lights should be:

  • About four inches from the soil
  • They should receive 16 to 18 hours of light per day.

Purchasing an automatic timer for the lights would be invaluable as this amount of light is ideal throughout the whole process.

Tip: Some strains of marijuana will require a more intensive light regiment as marijuana is a high energy plant. Some growers even expose their plants to light 24 hours a day. Usually, this will be unnecessary, but you may need to increase the light cycle at some point to improve growth and ensure the plants are healthy.

Even as the plant ages and grows, the light should remain as close to the leaves as possible without damaging them. A good rule to follow is:

Lower output bulbs: 2-4 inches away

Higher output bulbs: 4-6 inches away

The second factor is soil pH and texture. You could use the same soil throughout the plant's life if it has the texture to properly drain, so that the soil is neither too dry or too moist. Having soil which is either one can prevent the roots from getting the adequate amount of oxygen and water intake. The soil must also have a healthy pH. Between 6.0 and 8.0 is usually safe.

Watering Seedlings

No matter what form of plant it is, water is required and marijuana is not different. During the germination period, be sure to avoid drowning the plant with moisture. The top layer of soil should be kept moist by a few sprays from a water bottle. Upon sprouting, ensure you keep the stem dry as this is conducive to rot.

It can be easy to overwater the plant at this stage as excessive water can cause major issues with the soil such as the roots drowning due to lack of oxygen. This holds particularly true when watering seedlings in large containers.

Unfortunately, under watering and over watering the plants cause the same symptom in the plant (leaves drooping) so it can be a challenge to know which you are guilty of doing. Just be sure to check the dampness of the soil with your hand and adjust watering levels accordingly.

Overall, ensure that you take great care when watering the plants. In fact, it's a good idea to alternate between moist and dry to provide better aeration for the soil. 

Using the Correct Water

When growing marijuana, the water that is used is of vital importance as unhealthy water leads to an unhealthy growth. Many growers simply use tap water, which works well for the most part, but some areas put chlorine in water which kill beneficial bacteria. Luckily, even this usually isn't a major problem, as most plants can continue to thrive regardless. If you are worried, simply add some salt to the water, which will bond to the chlorine and make is harmless.

Tip: Adding salt can help, but too much can make your soil too saline.

Tip: Hard water will not harm your plants so avoid using water softeners as these can contain excess salt, which again, could harm the soil.

Transplanting Seedlings

Transplanting seedlings will only be necessary if you use a small container for your seedlings, and needs to be done once vegetative growth begins. Smalls pots can cause the plants to become rootbound, which in the worst case can cause death.

The process is as follows:

  1. Ensure the soil is moist in order to avoid jarring anything out of place.
  2. Insert a spade into the soil (or large spoon), roughly an inch from the stem.
  3. Take out a large enough clump to transplant fully, avoiding damage to the roots.
  4. You will need to have a prepared hole in the soil the plant will be transferred into, which should be dug in such a way that the seedling be at the same height as it just was.
  5. Place the plant into the hole and cover well with new soil.
  6. Moisten the soil so that the transplant and host meld well. 

Tip: This process requires a lot of care as shock to the seeds is common

Tip: Transplant plants when the first root tips grow out of the bottom of the pot

Vegetative Growth

Once the marijuana plant exits the seedling stage, it will enter vegetative growth. The growth of the plant will be exponential during this time, many leaves and branches will appear and it will start to look like an actual marijuana plant. The plants will live most of their lives in this stage in which proper environmental conditions are essential to growth. Luckily, you will have a great influence over these conditions as they are bred indoors.

Water and Lighting

As we have seen, these two factors can make or break a marijuana plant, a fact which becomes no less true in the vegetative stage.


The plants in this stage become thirstier and require larger amounts of water than ever before. Just be sure not to over or under water, which can be checked by looking at the moistness of the soil. Many growers develop patterns for watering, which can be as simple as watering one day, skipping it for two days and then watering again. It all depends on the plant. If the plant is still quite moist after two days then you can consider waiting another day to water, or if it is significantly dry then water it more often. It's pretty simple.


Marijuana requires a lot of light, which is one of the reasons it is so hard to grow outdoors in many areas of the world. For the best growths, it cans be necessary to keep the lights on 24 hours a day. Again, having an automatic light track can be ideal to move the lights around ensuring every plant gets intense amounts of light.

Ensure you keep an eye on the distance between the lights and the top of the canopy. At this stage, lights should be kept 20 to 30 inches above the plants as they will grow on almost a daily basis and you don't want the lights to be so close as to burn the leaves once they get closer, but not so far as the plants don't get enough light.

Tip: To avoid this, install an air cooling or water cooling system to reduce the heat the light produces. Unencumbered, light bulbs can create too much heat for the marijuana plants, but a cooling system will ensure that lights can be kept close to the plants while preventing burning. (We want to keep that for when the plant is finished).

Another important thing to keep in mind is that certain lights emit different color spectrum’s. Essentially, visible lights are the colors we can see on a rainbow (red, orange, yellow, green, blue, indigo, and violet). Marijuana tends to thrive in light under the red spectrum, helping to promote photosynthesis. High pressure sodium lamps (HPS) actually produce this color and are the best choice during every stage of the growing process.

Tip: Beware of anything high in the green spectrum as this produces wilting, unproductive plants, because the green of the plants reflect the green light entirely leading to less photosynthesis

Soil Control

Soil control is relatively important in the indoor plant growing process. Luckily, you will have a lot more control over the soil in the indoor process rather than in the outdoor process. Even so, unfortunately, soil can shift from the ideal pH of 6-8 that is needed for marijuana growth. If this happens, certain measures will need to be taken in order to avoid the death of the plant.


  1. Too Acidic- You can add lime to your soil in order to take out some of the acidic elements.
  2. Too Alkaline- Add cottonseed meal, lemon peels, or ground coffee, or even some fertilizers to take out the alkaline elements.
  3. Soil Flush- Although not usually recommended, it can become a necessary step in some situations, but only as a last resort. It involves taking your entire plant (pot included) and placing it in a sink. Then, turn on your faucet and allow the water to run through the soil to eliminate contaminates. This method can oversaturate your plant, but may be the only way to ensure your plant isn't killed. 

Nutrients and Feeding

A primary cause of irregularities in the previously mentioned soil pH is the influence of nutrients found within the soil. You can't simply use dirt; you need soil infused with nutrients, which can sometimes be achieved by simply using a fertilizer combination. In many cases, however, you will water in the nutrients using solution. Too many nutrients can make soil toxic, so be careful!

All plants need these nutrients to survive, and of course, marijuana is no different, and providing them with the necessary nutrients can be a big pay off in the end. The most important thing to remember is the nitrogen, phosphorous and potassium ratios in which nitrogen must be higher or equal to both phosphorous and potassium together. Fertilizers help with this and will, usually, be mixed with the soil prior to the growth process, but if necessary, solutions can be found to feed the soil the correct nutrients it needs.

Usually, the plant won't need to be fed frequently. In fact, if everything is progressing well then once a week is more than enough.

Tip: Never feed the plants with 100% of the nutrient because marijuana plants “burn” easily. Instead, dilute it to 50% to avoid having to flush the soil.

Other chemicals important to growth include:

  • Calcium
  • Magnesium
  • Sulphur 

Usually, you won't notice major changes in the amount of nutrients the plant does or does not, take in and will usually be the least of your worries in the growing process as long as the soil remains good.

Tip: Keep several diluted solutionson hand to make growing easier. A nitrogen, phosphorous, potassium solution where nitrogen is dominant is useful to have. Another could be one where phosphorus is dominant, which can help during the flowering stage. Diluted micronutrient solution is useful if the plants really start to turn for the worst.


Pruning the plants can help logistically and to produce more buds when the time comes to harvest. Indoor growers should keep their plants in check if they start to grow too high as one difference between indoor and outdoor growing is that the indoor plants often don't grow as large as outdoor plants can. Snipping off the top stem, however, can force the plant to grow wider and you can gain back what you lost in height back in girth.

Pruning is an important process to ensure uniform growth, but be careful not too much or often as it can make it difficult for the plant to grow back at all.

Tip: Many growers see it as a waste of perfectly adequate leaves and shoots, but even at this stage, these can produce a quality smoke and should not be put to waste.

Environmental Factors 

Every part of the environment your plant is exposed to can affect its growth in one way or another. Neglecting any part can be detrimental to its health and affect the quality of your bud. Now, we will go through five of the affecting factors.

    1. Air

Fresh air is extremely valuable to growth. Ensure you open up windows or install a fan system to ensure air circulates throughout the room. This can depend on outdoor weather conditions. If it is cold outside, be sure to only open the window for a short time to avoid the growth of the plant being stunted.

    1. Temperature

The temperature of the grow room should be regulated and kept at an average temperature of 75 Fahrenheit. Although, cannabis is quite good at adapting to lower or higher temperature, it is not recommended that you expose them to such. This can result in a lesser quality plant and a less potent bud when it comes time to harvest. In general, keep the temperature at 75 Fahrenheit and your plant will be healthy. Even if plants grow better at slightly higher temperatures, it may be difficult to maintain the temperature. Also, there will be a need for watering the plants frequently to counteract the extra heat.

    1. Lights and Temperature

Unfortunately, lights can cause problems when it comes to temperature maintenance. Lights often produce a great deal of heat, which can give the room a sweltering feel and dry up the plants or even burn them. As mentioned before, an air or water cooling system can help combat this. An air conditioner can help too, but is not very cost-effective. Ensure you monitor the temperature of your grow room on a regular basis.

    1. Humidity

Humidity (the amount of water present in the air) is something that affects every climate around the globe so don't think that you can escape from it. Even in your grow room. In general, 40 to 80% is ideal for growing conditions. Using fresh air can help achieve a good level of humidity in your room. You can also use a dehumidifier, but these can be expensive and are only recommended for large operations. However, you can get an rH meter to accurately check the ideal humidity percentages needed.

    1. Carbon Dioxide (CO2)

In order to survive, plants require CO2, which they convert into oxygen. It basically allows them to breathe. A good comparison is that while humans need oxygen to breath, plants need Carbon Dioxide as well. It even helps in the maintaining of photosynthesis so it is very important for the growth of marijuana. If your room lacks CO2, then you will need a CO2 generator. These generators will keep a steady flow of CO2 in a room and the plants will breathe it up. Don't worry though, a room without enough CO2 is highly unlikely.  

Determining Sex

Soon, the plants will enter the stage in which you will have to manually flower the plants when the plant is at its most potent, but first, you will want to determine which plants are male and which are female. 

In general, the plants will begin to “pre-flower” before you even begin manipulating them to flower. During this time, they will exhibit subtle signs as to their sex. The characteristics of male plants “pre-flower” stage are:

  • They will be taller than their female counterparts.
  • They may develop sacs that resemble buds, but in fact aren't.

The reason they grow taller is to ensure that they can pollinate the female plants. The pollen in their sacs drop down to pollinate the females.

The characteristic of the females “pre-flower” stage is:

  • It produces a white, hairy growth at the nodes and on the head. These are called pistils and they attract the males. 

Until these signs are present, it is very difficult to determine the sex of the plants, unless you cut one of the plants, and plant it in a separate area (it will be a clone of the original), then force flower this clone. You will be able to tell its sex, which will be the same as the original.

Many growers want to determine the sex as soon as they can as female plants produce a better high. This is particularly true for “sinsemilla” buds. Sinsemilla, meaning without seed, is when males are not allowed to pollinate the females and so the female plants will never produce seeds. These seedless plants are much more potent because they focus more on THC production and bud growth. You can practically see THC resin dripping from their buds. 

This requires taking out the male plants as early as possible. However, if you rely on your garden for the next harvests seeds, then this is not a good idea. Buying seeds from a dealer or even a seed bank is often a random grab bag of seeds, which you will be unable to identify where you could receive a full batch of males only or even hermaphrodite seeds.

Hermaphroditic plants are plants which have both sets of reproductive organs. These can exhibit early signs of both male and females plants. Although they may sound like a good deal, most growers will want to eliminate them from their crop if they want pollinated females, as these often only pollinate themselves, resulting in more hermaphroditic strains, which unfortunately have a lesser potency than females.

Tip: Male plants can produce a small high and can be used in cooking.

How to Force Flowering

Now that you can identify the difference between male and female plants, next you will need to get them to flower, but remember when you start flowering, it is difficult to stop the males pollinating the females if they haven't beenremoved. (even if they have been segregated). You just need to decide whether you want really potent buds for this year only, or to keep growing your favorite seeds by pollinating the female. (Buying new seeds can be costly so many pick the latter option.)

Either way, to force flower, simply put the plants in a 12-12 light regiment with the lights on 12 hours a day and the lights off 12 hours a day. The plants are generally programmed to do this.

Ensure the room is kept as dark as possible during the 12-hour dark period, as anything, from outside light sources to a flashlight shining in the room can keep them in a vegetative growth. If you have windows, be sure to block them out, especially if the sun rises before the dark period is over. Having your lights automatically timed can be a great help to the process.

During the flowering period, you should notice the female plants:

  • Starting to grow larger.
  • Produce more branches, buds, and flowers
  • Produce more THC
  • Take on a cone shape (like a Christmas tree)
  • Smelling fruity or smoky
  • Their pistils changing from whitish to a darker shade (generally brown, red, or orange)

At this point, they will be ripe for picking. If you want to pollinate the females, think about removing the male plants post pollination to give them room to flourish.

Indoor Problems and Pests

Indoor growers tend to not have to worry about diseases or pests attacking their plants, but it is still a possibility. In general, microbial diseases are minimal because the microbes affecting the plants don't usually exist in Europe or North America.

Nutrient diseases can occur, but those are just moments when plants get too many or too few, nutrients, which can be remedied as discussed before.

Pests are the real threat to the plants in your house because if they enter your home, they can easily attack your plants with no outside predators to stop them. Your best option is, of course, prevention, but sometimes pests slip past your traps and manage their way in, while mites and whiteflies and such can be difficult to detect at all and can get in any number of ways such as in your clothes or in the window cracks. 

If you have a houseplant that's resistant to pests, you may even already have them infesting your house. You can test this by placing a marijuana seedling in the pot with the house plant. If it shows signs of dropping or if the leaves start to turn whitish then you likely have mites.

Ensure you install a nylon mesh or wire screen to prevent pests entering your grow room and that your soil is pasteurized and sterilized fully to avoid larval eggs. 

Tip: Ensure you never use the same tools for your houseplants as you do your marijuana garden to ensure no cross contamination.


Eliminating Pests

You have several ways of eliminating infestation of pests of your home including: 

  • Insecticides (although these can be harmful to plants due to the chemicals involved)
  • Flowering early, as flowering plants can likely stand up to pests.
  • Removing infected plants from the healthy ones

If you are thinking about using insecticides, be sure to use ones that include things like pyrethrum, rotenone and malathion as these are generally considered safe for plants. (Of course, there is no need to spray the entire canister). These insecticides degrade into chemical compounds like CO2 and water when they stop working, making them very safe. 

Tip: There are natural solutions, but they often aren't as effective.

Indoor Security 

Another advantage to growing indoors is that security issues aren't a major problem, but they do occur. In many areas, growing marijuana is definitely illegal, and if anyone unfriendly gets a whiff of what was going on, you could end up in prison or facing a large fine.

No matter how cool you may feel, keep marijuana growing as much of a secret as you can. Don't tell your friends, your family, and acquaintance, or anybody that does not need to know. They may not take too kindly to your business.

Keep the Police Out

If you have a window in your grow room, make sure the plants aren't visible for the whole world to see. Also, leaving your light on at night could lead someone to be suspicious. Buying a blackout curtain for the room will ensure you avoid unnecessary intrusions, and will even be useful for keeping light out during the flowering process. It's a win-win.