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growing cannabis indoors from seed

Growing cannabis indoors from seed
There are several unique cultivation methods that use different types of growing mediums, such as hydroponics, aeroponics, or growing in coco. In this guide, however, we will stick with the traditional and easy way of growing weed in soil. Growing in soil has advantages for less experienced growers since it can be more forgiving with common mistakes.

Growing Cannabis Indoors

If you’re interested in growing cannabis, but don’t have experience with it, you may think that it would be rather difficult. Don’t despair! Even though growing cannabis may present some challenges, if you know about some growing basics and how to avoid common mistakes, it can be much easier than you thought!

Growing cannabis indoors has many advantages. Among them are the privacy and security of cultivating crops in your own home. Indoor growing also means that you have better control over your growing environment because you can provide your plants with the optimal lighting and temperature it needs. It also means a smaller risk of pests.

Our guide for indoor growing will help you get started on your cultivation journey. Once you learn the basics of growing successfully, a bountiful harvest will be just around the corner!

There are nine main elements to growing your plants. These elements are your grow room, your grow lights, the growing medium you use, the plant containers, nutrients, watering, the correct pH levels, air, and controlling/monitoring your grow. We will look at each of these in a bit. Before we do, let’s talk about another essential aspect of growing cannabis, how to successfully germinate your seeds.


Every grow starts out with germinating seeds. You can find plenty of information on the “best ways” to germinate, but let’s keep it simple! The least risky, easiest way is to germinate your sensitive seedlings right in soil.

To germinate your seeds, plant them about one centimetre deep into firmly packed and moist soil. A moderate temperature of 20-25°C is optimal. (Other germination methods like the “paper towel method” or germinating seeds in a glass of water all carry certain risks for your seedlings, so we won’t recommend these here in this guide).

Once you have planted your seeds, keep the soil moist and don’t allow it to dry out. However, also make sure not to overwater.

The quality of your seeds can also play a role in optimal germination rates. Quality cannabis seeds like those from Royal Queen Seeds have the best germination rates and they usually sprout within two days from planting.

Some recommended strains if you’re just starting out with indoor growing:

Royal Creamatic is an indica-dominant hybrid (60% indica) with a sweet maple-like scent and a great candy flavour.

Royal Dwarf is a compact and quick growing sativa-dominant hybrid (60% sativa) that delivers a potent, Skunky high.

Both strains are autoflowering and well-suited to beginners!



Your “Grow Room” could be a dedicated room in your home, but it can also be any suitable space. This includes a closet or a corner in your basement, or a grow tent. Growers have a lot of choices today with grow stores offering tents in all sizes. Before you plan on buying a grow space or tent however, consider how many plants you want to grow. Fewer plants are easier to handle. Should you ever run into a problem from pests or something else, any loss will be lighter on your wallet than if you were to lose an entire large crop.

A smaller grow space will also have lighter (and cheaper!) requirements for your grow lights, fans and other equipment. Just take into account that the space should provide your desired number of plants with plenty of space so they can grow.


The type and quality of your lights are perhaps the most important considerations for successful growing. Your lights are not an area where you want to pinch pennies or cut corners. Growers have an overwhelming variety of light options to choose from today, which doesn’t exactly help with finding the right one. Here are some of the most common grow lights.

HID Grow Lights

HID (high intensity discharge) grow lights are still widely used because they are very efficient and provide a good value. The most common HID grow lights are MH (metal halide) lights, which are used for the vegetative growing phase. HPS (high pressure sodium) lights give off a more reddish light, which is optimal for flowering.

LED Grow Lights

Among the other types of grow lights that are becoming increasingly popular are LED grow lights. LEDs have several advantages over other types of lights. They are now very efficient and use far less electricity as compared to HID lights. Their disadvantage is that they can cost a lot more. Know that the market is currently flooded with low-quality LEDs, so getting a good one will require some research or the advice of experienced growers.


There are several unique cultivation methods that use different types of growing mediums, such as hydroponics, aeroponics, or growing in coco. In this guide, however, we will stick with the traditional and easy way of growing weed in soil. Growing in soil has advantages for less experienced growers since it can be more forgiving with common mistakes.

On the other hand, there are vast differences in the quality and makeup of potting mixes (soil) that you should know about. Most good-quality potting mixes are essentially suitable for cannabis, but you should avoid those which contain so called “extended release fertilisers” like Miracle Grow.

Almost all widely available potting mixes come pre-fertilised, but these nutrients won’t usually last for the entire duration of a grow. As a rule of thumb, you can expect the nutrients in a commercial potting mix to last about 3-4 weeks (usually covering the vegetative phase of your plants), which means that you should start giving additional nutrients as soon as flowering starts.

Some more experienced cultivars like to make their own organic potting mixes, so called “super-soils,” where they add all types of beneficial ingredients like worm castings, bat guano and other things for optimal growth.


You can find all types of containers for growing, from the most simple plastic containers and fabric “grow bags” and “smart pots,” to fancy self-watering pots. But when it comes to choosing standard pots, there is really not much to it, except that you want the right size for your plants. It can be a good idea if you start out with 20L pots. What’s important is that the pots provide adequate drainage. This is why pots will normally have holes at the bottom. Some pots may require you to break out these holes first before you use them. Tip: Rectangular flower pots are particularly well-suited for indoor growing in tight spaces!


Unless you are using a pre-fertilised, organic potting mix that covers the entire duration of a grow, you will at some point have to feed your plants with nutrients. Cannabis nutrients are available as liquids or in powder form. You add these nutrients according to specific instructions when you water your plants.

What’s important to know is that cannabis nutrients are normally available separately for the vegetative grow phase and then for the bloom/flowering phase. This is because cannabis has different nutrient requirements depending on the stage of growth. Most of the time for your grow, you will have at least two bottles and possibly more depending on the micronutrient regimen of your crop.

Nutrient burn and other growing troubles from too many nutrients are very typical among less experienced growers. To avoid overfeeding, you should start with half the recommended dosage. Otherwise, stick to the instructions for your brand of nutrients while understanding that the makers of these products normally tend to recommend too much – after all, they make money from selling you their stuff!

For seedlings, you should not feed at all for 2-3 weeks and only start giving light doses of nutrients once they have their 3rd set of real leaves. Overfeeding seedlings is a very common first time grower mistake!


Watering your cannabis plants right may sound like the easiest thing, but many new cultivars do this improperly!

Rather than watering your plants lightly but frequently, it is better to water them less often, but well. When you water, water them thoroughly so that the entire soil is saturated, until water drains out from the bottom of the container. Wait between watering and allow the soil to dry out again. (A good way to check this is by weight if you lift your pots up). It is much better for your plants to be slightly wilting than to overwater them! Overwatering is one of the most common reasons for all sorts of growing troubles!


Watering your plants (and feeding them) is not everything. Almost equally important is maintaining the right pH level of your water or nutrient solution. This is because cannabis can only take in nutrients when the pH level is right. For growing in soil, the pH for your water should be between 6.0 to 7.0. Use pH measuring drops or a pH meter to check the levels of your water. Increase or decrease the pH level accordingly with “pH down” or “pH up” products. You can also use lemon juice.

Cannabis needs air for optimal growth. Some experienced growers may have elaborate systems in place to provide their plants with CO₂ and to get rid of odours. But we don’t need to go there yet. A simple fan can be all that you need to start. A gentle breeze of air can help to keep temperatures in check, prevent mould and keep insects at bay. Furthermore, a constant but slight breeze over your plants can make them grow stronger stems and branches.


We’re almost there, having set up an optimal environment for our cannabis plants! We have a nice grow room or tent, we hooked up a light and a fan. We got all the nutrients and then of course, some quality seeds that are just waiting to grow!

What’s left to do is to control and monitor our grow for best results.

The one thing that you definitely want to control is the ratio of light exposure your plants receive. This involves manually regulating the light/dark cycles of your grow lights. As a new grower, you will likely choose autoflowering cannabis strains where the light cycles are not important yet. So set your grow lights on a timer to provide your autoflowering plants 18 hours of light per each 24-hour period.

For advanced growing, such as when you grow non-autoflowering strains that rely on the light cycles for their vegetative and flowering period, you would also control these using your timer. In this case, you would initiate flowering once you switch your lights to a 12-hour darkness cycle per each 24-hour period.

Once you understand these fundamental elements of indoor growing, you can look forward to a bountiful harvest in no time. As a final tip, don’t let some growing setbacks ever discourage you from trying again. After all, this is the way you learn to become a master cannabis grower! Know that no one is born a pro and that all of us were new to growing at some point. Good luck and happy indoor growing!

Once you get your feet wet and are eager to learn more, visit our blog for other helpful articles on cannabis growing techniques.

I’m an organic gardener. While I don’t object to a little bloom booster to convince some reluctant annuals to step it up, I want everything that goes in my body to be as natural as possible. Plants need nitrogen to grow. When I had access to a mountain of free rotted horse manure, I fertilized with manure tea.

How to Grow Your Own Cannabis Plants From Seeds

Takeaway: Back in the last millennium, before cloning swept the country like the hula hoop, people actually grew cannabis plants from seed. Primitive, huh? But where there’s a will, they’ll surely find a way. While that’s all changed now (hello, cloning!) you can only clone so many times before you have to buy more plants or get back to basics with seeds.

Growing from seed is all about the quality of your seeds. Plants will never be better than the seeds they grew from. Back in the day, there weren’t any seed shops, so seeds were saved from exceptional buds, but it was all a crapshoot with a lot of trial and error. Luckily, now we know better.

Starting from seed isn’t difficult and you don’t need to be an experienced gardener, but the process is a journey in stages, not a direct flight. Cannabis plants are perfect for growing from seed because they have a short life cycle. That being said, be prepared to check your plants every day for moisture, insects, diseases, nutrient deficiencies and light. If you can’t make the time and work commitment, perhaps you should forget the idea. Here’s my list of what I used for my first grow. Nothing high-tech—my grow room was a walk-in closet with louvered doors and a clothes bar to hang my lights.

  • A four-foot table or two sawhorses with plywood on top
  • A piece of thick plastic or a waterproof tablecloth for spill protection
  • Potting soil for seedlings
  • Clean sand
  • Seeds (of desired strain if purchasing)
  • Five-gallon pail for mixing soil
  • A four-foot shop light with chains and S hooks
  • One full-spectrum red fluorescent grow light
  • One regular white fluorescent tube bulb
  • Light timer
  • Five-ounce opaque drink cups
  • Eight-ounce drink cups
  • pH kit
  • Plant flats or trays
  • Plastic kitchen wrap

Best Lighting for Cannabis Seedlings

If you’re on a budget, fluorescents offer the biggest bang for your buck when getting light to you cannabis seedlings. Don’t forget to factor in the cost of electricity and bulb replacement. To make sure all my plants got an equal amount of light, I turned the trays 180 degrees every day. I especially liked the ease of raising the shop light one link at a time as the plants grew. You can maximize your light by using a room with white walls or surrounding your grow table with movable reflecting foil-covered cardboard or hanging sheets of Mylar—mirrors don’t work well for reflecting light.

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Germinating Cannabis

Mature cannabis seeds are dark brown, sometimes with swirly patterns or stripes. Discard immature pale or greenish-colored seeds. I’ve never started seeds in soil, preferring the Japanese method of “proving” seeds first; there’s no sense planting dud seeds. I germinated my seeds in a moistened, loosely rolled up paper towel on a plate in indirect light on the kitchen counter where I could keep an eye on progress. Keep the paper towel moist, but not lying in a puddle of water or the seeds will rot.

Some seeds germinate in a couple of days, while some take up to a week, depending on their temperature. It’s helpful to know that the seeds will produce male and female plants. Back in the Dark Ages, I always started 16 cups of seeds in hope of ending up with four females. That’s no longer a problem if you can buy feminized seeds, which are guaranteed to be females. I planted two sprouted seeds about one inch apart per cup because frequently one seedling will be bigger and stronger than the other. Go with the bigger one and pinch off the smaller one at the soil level.

The beauty of starting seedlings in the opaque cups is that you can see the root growth. Poke some drainage holes around the cup bases. It’s quicker to do the drain holes with the cups in a stack. As you finish each cup, slip it in the other end of the stack or you’ll waste crumpled up cups. Mix the potting soil with enough sand to give the fluffy soil more body. Add water gradually, mixing well to moisten.

Fill the cups with the soil mix and tap each cup a couple of times on the table to eliminate air pockets. Add more soil if needed, tap it down again to leave a half-inch space between the top of the soil and the rim of the cup. Repeat until all the cups are filled. Set up your grow table and lights. Ready? The table is all set. The lights are on. The cups are shoulder to shoulder in rows, waiting to fulfill their roles.

Transplanting Cannabis Seedlings

My tools of choice for planting were a small wooden matchstick and a wooden toothpick. I made two small holes with the clean end of the match about one quarter inch deep and a half inch apart and not too close to the side of the cup. I picked out two sprouted seeds at a time from the paper towel, careful not to touch the sprout, and dropped them into the match holes and used the tip of a toothpick to scuff soil into the holes, then lightly tamped the spots with one finger. Keep the remaining sprouted seeds covered so they don’t dry out. Repeat until all the cups are planted.

Put as many cups that fit into shallow flats or trays and then drape a long piece of kitchen plastic wrap over everything, tucking the ends under the trays to create a mini greenhouse. When this step is finished, the plants get to sunbathe under the lights for the next six weeks or so of the seedling phase.

In a few days, two primary leaves will appear and you can do your happy dance. Soon the next pair of leaves will appear and the first ones will drop off. If condensation forms under the plastic wrap, uncover the seedlings to release the excess moisture and then replace with fresh wrap. During the seedling phase, keep the soil moist but not wet and only water from the bottom from so the roots stretch down long and strong.

Water with a spray bottle until the first leaves appear, and then water from the bottom; the soil around the stem needs to stay dry to avoid stem rot. Fill pitchers or buckets with tap water and let sit uncovered until room temperature and the chlorine has evaporated into the air. Hard water is fine, but don’t use artificially softened water because it contains too much salt and other harmful additives.

I’m an organic gardener. While I don’t object to a little bloom booster to convince some reluctant annuals to step it up, I want everything that goes in my body to be as natural as possible. Plants need nitrogen to grow. When I had access to a mountain of free rotted horse manure, I fertilized with manure tea.

Throw a shovelful of manure in a bucket, fill with water, let it sit a couple of days and water with the tea. It worked fine for me. There are “hot” manures and “cold” manures. Hot manures have the highest nitrogen, but have to be aged. Cold cow manure has lower nitrogen but can be used hot out of the barn. Rabbit manure is cold, but some growers call it nitrogen on steroids. If slogging around in barnyards doesn’t appeal to you, you could use fish or seaweed emulsions or any of the other excellent natural fertilizers available at your local hydroponics supplier.

Check your soil pH regularly. Plants grown in soil like a pH about 7. If your soil drops below 6, add a light sprinkling of ground limestone before watering. If the soil is above 8—too alkaline—sprinkle around a concoction of cottonseed meal, lemon peels and ground coffee.

For repotting, discontinue the plastic wrap when the third set of leaves appear. When you see that the roots have reached the bottom of the cups, it’s time to repot the little darlings into the eight-ounce cups. In my experience, the plants do better stepping up to the bigger cup instead of going directly into three-quart pots. Repotting can be tricky, so take your time here. The plants shock easily with too much jostling or rough handling. Get the larger cups ready, poke the drain holes and fill with enough soil mix so the seedlings will be at the same depth as in the first cups. Before removing from the smaller cups, lightly water them so everything stays together.

Tip the cup upside down in your open hand with the seedling stem between your fingers. Gently squeeze the sides of the cup with your other hand and the seedling will drop out in one piece. Don’t pull it out by the stem! Place the seedling in its new home, filling around it with more soil, and make sure it isn’t deeper or shallower than in the smaller cup. This is important. Compress the soil lightly for any air pockets.

Entering the Vegetative Stage

During the vegetative phase, leave the lights on 24/7 and as close to the leaves as possible without touching. If the lights are too high, the stems will grow weak and spindly. You want the plants to remain compact. When your plants really take off, they may grow an inch a day. Keep a sharp eye on the distance between the tops of the plants and the lights. Fluorescents are cool and won’t burn the leaves, but keep adjusting your lights upwards to stay ahead of the growth.

Rotate your plants so they all get enough light. When plants are starting to bud, rough handling or a sudden change in temperature or light will drive them into shock. When you see your plants are beginning to outgrow the cups, it’s time to pot up again, this time to three-quart containers commonly found at nurseries. Always wash used pots in hot soapy water before reusing.


Toward the end of the vegetative and budding phase, you’ll be able to sex your plants. Males have two pollen-filled sacs that are easy to see and females have a pair of white V-shaped hairs. One male plant is enough to pollinate all your females so they produce seeds. I didn’t grow for seeds, so I quickly yanked all the male plants. Male plants are low in THC, are harsh-tasting and give many people a massive headache. Unpollinated females produce more flowers, buds and THC.

For even more plants, remove the unproductive lower stems and leaves on your plants, and then make two or three shallow downward slices on the main stem with a clean blade and insert a graft slip dipped in root stimulant in each cut. Put a small piece of tape around the cuts. The grafts can be other varieties, not just the same as the host plant. Soon you’ll have new growth from all your grafts, giving you maximum yields.