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Growing Weed indoors a Guide for Beginners in Canada

What you need to know to Grow Weed Indoors

This blog is a guide for beginners in Canada (or elsewhere) interested in growing weed indoors or anyone who wants to grow in their own home.  This guide is easy to understand and purposefully designed to help you to grow marijuana indoors.  Whether you decide to grow your plants indoor or outdoor, you will find many tips to help you along the way.

The best part here is that you will never have to buy overpriced, or bad weed again.  One benefit of growing weed indoors is that you can be discreet while growing your plants and no one needs to know.  You no longer have to get involved with dubious or dodgy dealers when it comes to having a source of marijuana.  The cultivation of the weed plant is easy because it is a fast-growing and robust plant. 

With the right conditions for growing weed indoors, it can grow like a weed.  Indoor cultivation, when appropriately done,  takes about four months from seed to a final smokable product. 

Where to Grow Weed Indoors

Growing weed indoors definitely has its benefits; one being you are able to control your environment and climate a bit easier than growing outdoors. 

Also, you are not dependent on the weather. Cannabis needs as much sun or light as possible.  Ideally,  your grow space can be in a small room such as a cupboard, a garage, a basement, a loft or your garden shed or grow box/tent. If possible and you have a choice look for a space that has adequate ventilation.  Ideally, if you can find a space with a window or vent to get rid of the used air.  Also using a fan can also help with air exchange.  All attempts should be made to circulate fresh air in and around the plants throughout the growing weed indoors process.  We found that our garage was the perfect place for our plants since they were not inside the house so we were able to decrease any aromatic smells coming from our lovely plants.

What you will need to Grow Cannabis Indoors:

Grow Equipment and Accessories

The basics you will need to start your weed plants are mostly available at your local hardware store or garden center.  If you have a local grow shop around check them out as well since many times they have beginner grow kits available and also have many handy tips for beginners.

 What you will need is the following:

  • Seeds
  • Grow lights/lamps
  • Grow box or tent
  • Ventilation or fans to circulate air
  • Pots (5-gallon plastic containers with holes drilled in the bottom)
  • plant food, compost, or fertilizer

Indoor Cannabis Growing Lights:

hps grow lamp

The Cannabis plant requires sufficient lighting. Therefore, special grow lamps are needed when growing weed indoors.      During different phases of growth, your plants will require different spectrums of light. The best choice of indoor grow lights for weed currently is HPS (high-pressure sodium vapour lamps). They produce a lot of light per wattage and are relatively inexpensive to buy. The disadvantage is that HPS lamps produce a lot of heat and need a lot of power.

Alternatively, you can go with LED grow lamps. These are as good in quality and function but slightly more expensive to buy. The main advantage of the LED is that the LED grow lamps use a lot less power, do not produce heat, and have an incredibly long life.  It is not ideal however if you want to grow on a very small scale, you can also use CFL (compact fluorescent lamps) With one 150 Watt CFL lamp around 1-3 small plants can be reared.  Again this is not the best case scenario and will definitely affect the yield and quality.

Indoor Air Flow and Exchange for Growing Cannabis:

Cannabis needs fresh air to grow properly at every cycle of growth. Cultivation areas that are not well ventilated tend to develop insects such as spider mites, or mold residue which can reduce and damage crops or completely decimate your plants.  There are ways to get rid of mold or mites but in order to eliminate them in the first place is to spend time planning the air exchange.  It is very important that you get rid of old used air.  For example, by using a window or a small vent.  One important tip is that a carbon filter or a ventilation system removes the typical marijuana smell so that others will not notice the aromatic smell coming from your grow box. Very small setups can be operated without active ventilation.

If you decide to go with a Growbox or the cultivation tent it can be extremely successful on a very small scale.  There are many benefits of using a grow box or tent:  

  1. It keeps all your light inside a small space and will maximize the light coming from your grow lamps.  
  2. It keeps the smell of the plants inside to a minimum and can be removed directly with proper ventilation.
  3. The grow box is lined with a reflective interior to direct intensity of light to the entire plant top to bottom. 
  4. They are available in many different sizes depending on your scale of growth.
  5. They usually have a waterproof bottom and are relatively easy to clean

There are a many different types of grow boxes. You can even make one yourself from inexpensive wood and other building materials. Be sure to create two openings bottom of the box and top of the box. The idea is to push the air up and out. Has openings for the electrical connections

Seeds for Growing Cannabis Indoors:

There are many sites now selling seeds at a decent price.  Do a little bit of research first to figure out what kind of strain you want to grow and then order away.  Keep in mind that you will need about 1-2 weeks to germinate your seeds before you plant them.  There are a few favourite ways to germinate your seeds, but whatever way you choose make sure you give your plants the best possible start.  One helpful hint when purchasing seeds once you get them visually a healthy seed will have a nice marble colour but a dead seed is hollow or black.

How many seeds should you start with maybe your next question?  It will mostly depend on the space that you have available.  Too many plants crowded in one space can affect aeration and once the plants mature in size their leaves will need the space to open up and absorb adequate light.

Next, make sure that you buy feminized seeds.  Male weed seeds do not produce buds with THC and therefore will not give you anything smokeable, and if they are grown close to female plants they will ruin your crop.  Most seeds for sale now online are feminized but just make sure that you double check before you check out so you don’t waste your money.  If you buy all feminized seeds, it means that all seeds will produce female plants.  Also, if you are planning to grow let’s say 4 plants you may want to order a couple of extra seeds just in case some do not germinate you will have some on reserve if needed. 

5 steps in germination growing phase:

  1. We use Jiffy peat bales or Cocos-Pellet place them in water and let them soak until they are full of water and are big and fat.
  2. Put only 1 seed in each peat bale. The seeds should be inserted 1/2 inch deep (2 cm) and lightly covered with soil.
  3. Put all peat bales in a plastic container or on a plate.  Let them stand at room temperature. As long as the plant is not germinated, it does not have to be under the light. Always keep the peat bales moist. Pour water carefully into the container, the peat bales will absorb it. Do not pour over the peat bales or the seed will be washed away. In about 3 to 7 days your plants will sprout.
  4. Turn on the lights in your growbox (or in a well-lit and warm window for the first week). The light must now be switched on for 18 hours and switched off for 6 hours. Program your timer for this. Put the new babies under the light.
  5. They will grow very fast, keep them moist but be careful not to over water them.  It is important that they are not left in a puddle of water.  Soon, roots grow out on the sides and bottom of the peat bales.  At this point, you must transfer your sprouts into their final destination in the pots you have chosen.

Your sprout grown indoors is ready to relocate

Once the sprout has grown out of the jiffy peat pellet, plant it in a pot of fresh plant soil (Grow Earth) or whichever medium you have chosen.  Again do some research to see what is available around you.  A hint when choosing soil we went with tomato soil which worked quite well for the duration of life of the plant.  Next, you will want to fill the pot with soil, make a deep hole in the middle and insert all the jiffy peat pellet with the young sprouting plant.  Put the peat bale down to about half of the stem of the plant in the ground. This will give you additional support for your plant.   Cannabis roots grow deep so make sure that you have a deep enough container for your plants or your roots will get crowded and affect your yield.  Gently and easily press the soil around your plant and add water.  At this point, it will be very important to check the soil on a day to day basis to make sure you are watering adequately.  Soil should be moist to touch if it is dry then add some more water. 


Cannabis grows very fast and continuously drinks plenty of water. However, it is important to monitor your soil since over-hydration can kill your crops very quickly. Young plants need watering about 2-3 times a week.  Mature plants depending on how dry the environment will require watering once a day or once every other day.

There is no set rule for irrigation. You must water the plants when the soil is dry.  Also since the root system of larger plants are deep make sure that you are not just surface watering your plants.  Drilling drainage holes in your plastic containers for water to run through is the best way to ensure that your roots are getting enough water. 

If you do not have adequate drainage your roots will be sitting in water and your plant will most likely rot. We have been very successful with Home Depot 5 gallon plastic pails with multiple 1-inch holes drilled in the bottom. Another thing to consider is as more and more chemicals (chlorine, fluoride) is added to our water supply, it may be beneficial to use filtered water.

The Vegetative Stage – The Beginning Growth Phase

So at this point, your plants are sprouted and you have successfully planted them in pots. They are under the grow lights of your choosing and the magic is starting to happen. At this point, it is also important not to have your plants too close to the grow lamp.  This can cause the leaves to burn or dry out.  Especially in the beginning, your first round of leaves that will grow is your fan leaves which are essential to the plant absorbing the most light as possible.

At this point in the vegetative stage, your lights should be set to 18 hours on and 6 hours off. This is the light cycle of the vegetative phase.  Some people would say to leave the light on for 24 hours but to stay on the safe side use 18/6 since it also allows the plants to sleep and stay healthy.

Leave the plants for about 4 weeks under 18 hours light. Check your soil daily and make sure to clip any dead leaves which you really should not have at this point if they are healthy.  Now its time to make your ladies bloom!

The Exciting Indoor Growth Stage – The Cannabis Flowering Phase

After about 4 weeks in the vegetative phase, your weed plants now require a switch to a more seasonal representation of daylight. This will mimic closer to fall light ratio which is more evenly distributed to 12 hours of sun and 12 hours of dark. This, in essence, tricks the plant into thinking that summer season is ending and will naturally force the plant into a flowering stage to reproduce for the coming season.  Now your Cannabis plants will shift from the “vegetative” (growth phase) to the flowering phase. The plant thinks it’s late summer and it’s time to flower and produce your first buds! 

In order for easier adjustment to light change, you can slowly decrease your hours of light.  For example, each day add a couple more hours of darkness to the schedule ie. 15 hours light then to 14 hours, to 13 hours until you have arrived at 12 hours of dark and 12 of light. This would simulate the natural seasonal process your plants would see in the wild. 

If you have reached this point and your plants are still thriving you will notice the first flower buds after about 4 weeks 12/12 light to dark. If for some reason you have not used feminized weed seeds, this is the point where you will determine the gender of your plants.  This is why it is important to use feminized seeds.  If you have a mix of male and female plants that are close to each other the male plants will fertilize your female plants and ruin your crop.  You do not want your buds to be fertilized by the male plants. This is a good reason to keep your plants separate at this stage until you are sure you have all females. Another point to make here is in Canada you are only allowed 4 plants per household. You should ensure you will be able to harvest all four plants to maximize your yield. ALWAYS purchase feminized seeds.

After about 4 weeks, the first flowers will be visible.  Both males and females have flowers but they look visibly different.  Females have whitish hairs while the and males plants produce hanging ball-shaped buds. You must remove the males as soon as you have identified them because they will pollinate the female plants.

Feeding – Fertilizer, Plant Food for Better Indoor Cannabis Growth:

Cannabis plants have a pretty hardy appetite and the food that you feed them is can sometimes be the difference between a large yield and a smaller one.  Clearly, you want to get a large yield of smokeable bud as possible and this is where the difference lies.  Marijuana plants grow fast and require a lot of nutrients and some at different stages. There are fertilizers specifically for hemp available online and for beginners growing weed indoors, this may be your smartest option.  These fertilizers are specifically balanced to feed the plant during its different cycles.  It is not recommended to go to your local nursery to purchase fertilizer but if there is no other option it can be better than nothing.  They will work but they are not optimum. Since you are committing a lot of your time and energy into the growth of your weed plants it is best to purchase plant food that has been tested tried and true specifically balanced for Cannabis plants.

For the best results, you should use a range of growth and bloom fertilizers.  Always look for organic if possible and specific to the stage your plants are in.  For beginners growing weed indoors, if you are trying to decide which stage to fertilize in it has to be the flowering stage.  At this point, if you only feed your plants properly during this stage you will likely increase your yield at the end and will best see results from fertilizing your plants.  Look for a fertilizer specific to flowering it will say in the description and will be best suited to feed your plants with the proper ration of nutrients.  

If you have used good quality soil and compost, your plants do not need fertilizer before the 3rd or 4th week. There will be enough nutrients in well-sourced soil to get you through this phase. But after that, it is important to use proper doses of fertilizer.  The amount you fertilize will also be important.  

For most fertilizers, the nutrient solution is diluted into the water that you use for the plants. How much depends on the product and it is important at this point to carefully follow the instructions given usually found on the container. The younger your plants, the lower the dosage.  Dosages are very important and if the dosage or dilution is not correct it can lead to nutrient burn where it can affect and even kill your leaves.  You do not want this so be careful when dealing with dosages of fertilizer.

How is fertilizer administered?

Fertilizer is mixed in proper ratios with the water you are using for irrigation.  Also if possible use filtered water so that you are not introducing other elements found in tap water.  Depending on where you live and how your tap water is treated you can have higher than normal sodium, chloride, or even fluoride in your tap water and can affect the growth of your plants.  Again always follow the product-specific dosage recommendations that are given on the bottle.  If you have found a local grow store many times they are very knowledgeable in plant food and can help you choose what will best suit your plants.

Start with a mixture of low concentration and increase the dosage and frequency over time. If your plants get yellow leaves, especially in the middle or on top of the plant, you are not supplied with enough fertilizer.  In contrast, too much fertilizer can have similar effects by burning the leaves but this usually occurs near the tips of the leaves.  At this point it may also be useful to do some research online there are a few sites we found to be very helpful in identifying whether you are using too much or too little fertilizer.  Also, keep in mind that note that mostly all weed plants get yellow leaves at the bottom of the plant at some point in their lives. This is normal.

If the sides of leaves your weed leaves are rolling up or under, you have probably been using too much fertilizer. you might also notice browning of the weed leaves at the tips. This is a sign of nutrient burn. If this starts to happen to flush your plant with just filtered water for the next two waterings to help it return to a normal state.  In general, you should always keep an eye on your plants by inspecting the leaves when you water.  Healthy leaves have a dark green colour. They will have no dried, yellow or brown spots.  

Inspect your indoor grow for pests

It is always a good idea to inspect and watch for pests as your plants grow.  Even with growing weed plants indoors where there seems to be no way for pests to get to them it is still very possible to occur. If you notice small white dots on your leaves, make sure to take a close look at the underside of the leaves and inspect them very carefully to properly diagnose what it is.

The most commonly found pests are often “spider mites”.  If you suspect spider mites it is important to treat your plants right away.  If spider mites are left untreated they will coat your plants in cobwebs and slowly kill your plants.  To fight these militant pests, buy a mild pesticide. Most growers recommend Neem Oil for this specific problem. It is an organic choice and will not harm your crop. Remember, your harvest is for human consumption. You can not use strong poisons for treatment or you will be smoking that in your bud.  Always choose organic when possible.

Follow the directions on the bottle of neem oil for mixing your spray. Wait for the lights in your Growbox to shut off for the night. Then generously spray the entire plant from top to bottom. Pay special attention to the undersides of the leaves. Make sure that the plants are dripping wet.  Let it dry until the lights come on again. Repeat this process if it is necessary. This should expel the vermin. 

When will my weed plants mature?

It will take about 2-3 months of flowering time until the weed is ripe and ready to harvest.  During this time, you will notice the flowers/buds will grow with changes being seen daily.  Continue with your regimen of watering and feeding your plants and you really can not go wrong.  Your weed plants are fairly forgiving at this point. 

Flowering time depends on the weed strain you grow. Generally, varieties with a high Indica percentage have the fastest-growing buds.  While the Sativa strains generally take a bit longer during the flowering stage to fully mature. The new Automatic Cannabis Seeds are the varieties that have the shortest duration of flowering and are therefore the quickest to harvest.

Now is the time you have been waiting for when the excitement of harvesting is right around the corner.  Your plants are ready for the final stage of the indoor weed growing process.  If you have gotten this far successfully it will only be a short time before you are able to enjoy your final product.

Determining the ripeness

You can determine the degree of ripeness by the colour of the hairs that have sprouted from the buds.  The hairs on the buds will start out as little white hairs and slowly but sure start to turn a more brownish colour once they are getting fully ripe.  If and when about 70% of the hairs are brown, then your weed plant is ready for harvest.  At this point, if you have not already noticed your plants will be highly aromatic with a very strong smell and your buds will be compact and hard.

If you have a magnifying glass or a jewellers lens you can check the trichomes (sticky, crystal-like fine hairs on flowers and petals) for their colour. If they appear brownish in colour this is your indication that the plant is ready to be harvested.

Plants that are harvested very late, regardless of variety, tend to have a more drowsy and soothing effect. By contrast, early-harvested plants seem to have a more active high. This is probably related to the formation of the cannabinoids. A very important medical cannabinoid that is still of medicinal value before THC is CBD ( cannabidiol ). CBD develops “noticeably” only in the later flowering stage.

Growing  Cannabis Indoors – The harvest!

Harvesting is very easy and fun and can be quite therapeutic in my experience.  It is what you have been waiting for the main event and there are some important things to remember while harvesting and drying your weed.  To begin cut the whole plant a few inches above soil level. During the harvest period try to avoid touching the sticky flowers/buds this removes the crystal from the bud and makes everything sticky. Just remember that everything that sticks to your fingers is lost. 

Now the real work begins. It is now time to trim the leaves and flowers.  With scissors to remove all leaves from your flowers.  You can just dispose of the big leaves in compost or garbage they are no longer useful. They have almost no active ingredients and smoking them would only make you cough.

Make sure to keep the smaller, resin-covered leaves between the buds. You can trim them or cut them off, but keep them and dry them and they can be used for shake.  They are smokable, but they seem even better suited to make butter or hash.

The cleaner you cut your buds, the better they will look. And the more beautiful they are when they are smoked.

Drying your precious harvest

Dry your buds slowly but not too slowly.  For example, a good way to dry them is by spreading the buds on a paper or a screen and drying in a dark cool dry room.  Do not force dry your weed with tools like hair dryer or dehumidifiers. Speeding the drying process will destroy a significant part of the active ingredients and it will then taste and smell like hay. Besides drying is the least amount of time that stands between you and your smoke. The next stage is curing.

In contrast, if they dry too slowly or you have higher humidity levels, they could start to mold which is devastating at this point and would ruin your entire harvest.

If they dry slowly you will notice that they will develop a pleasant smell and taste. Drying them slowly will also make them milder in the smoke and will take away the harshness you can get sometimes.

Your flowers should feel dry after about 7 days of drying time. Then put the buds into a large plastic bag overnight and make sure not to compress.  The next morning they will feel slightly damp again. Remove your beautiful buds from the plastic bag and let them dry for another 12 -24 hours. Then they put them back in the plastic bag.  You can also use mason jars for this stage as well.   

Continue to check on the drying progression. When the small stems break completely, this is the time to stop drying. You should not dry it 100% since low moisture is needed for the curing process.

Growing  Cannabis Indoors You can smoke

You can smoke her now but it is better to wait a few more “months” for your final product to be cured.  The purpose of curing is to make good buds even better.  Your freshly dried marijuana can be consumed. It will still produce the desired effect when smoked but curing it will just improve on its overall effect.

In the next 2-4 months or so if you have the patience to wait that long, chemical processes in the flowers will decrease (ferment) chlorophyll and increase THC + other agents.  This means that marijuana will be easier to consume and stronger in its effects.  Hardening is best done in mason jars. The glass of the mason jar is neutral, whereas plastics can give off its taste on the flowers.

Now just put it in glass containers and store in a dark place. Open the mason jars daily to “burp” the jar so that you let some oxygen in.  This process is a bit like making wine or cheese. There are no fixed rules so do some research and make it your own.

If you have successfully made it this far congratulation you have now grown your first batch of Cannabis plant.  Now sit back, grab a snack and some friends, and enjoy the fruits of your labour.

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