How to Germinate Cannabis Seeds - The Ultimate Guide For 2021

Posted by 29/09/2021 0 Comment(s)

How to Germinate Cannabis Seeds - The Ultimate Guide For 2021

The life cycle of a cannabis plant begins with germination, followed by a vegetative state, and ends with flowering right before harvesting. But for premium-quality cannabis buds, using high-quality cannabis seeds is crucial.


Although germination only takes 12-36 hours, cannabis seeds are pretty delicate and require precise humidity, temperature, and darkness to germinate. Other factors like seed quality, seed storage, and the germination method also influence germination rates. 


If you are planning on germinating cannabis seeds, we have you covered.  We’ll delve into everything you need to know about cannabis seeds and offer a step-by-step cannabis germination guide.


Types of Cannabis Seeds

At first glance, cannabis seeds may all look the same; however, the seeds often undergo genetic modifications to preserve or enhance their specific genetic traits. Some cannabis seeds also feature modifications to adapt to growing conditions.


Below are the main cannabis seed classifications available on the market.


Autoflower Seeds:

Cannabis plants are naturally photoperiodic, meaning that the amount of exposure to light during their vegetative stage determines when flowering starts. However, unlike photoperiodic cannabis seeds, auto-flowering seeds transition from the vegetative stage to the germination stage regardless of ambient light exposure.


Note that cannabis is a periodic plant that transitions from the vegetative stage to the flowering stage naturally between summer and fall. It is the reduction in duration of exposure to sunlight that signals the cannabis plant to start flowering.


Autoflower seeds feature the genotype of a cannabis species called Cannabis ruderalis. The unique cannabis species found its way to the Scandinavian region that experiences sunlight day and night and adapted the auto-flowering mechanism to survive. Therefore, auto-flowering seeds are ideal for controlled germination because you will not need to adjust light during flowering.


Besides auto-flowering environmental adaptation and being easier to grow, auto-flower seeds also mature faster and allow you to harvest cannabis crops twice a year. However, given the seed’s modifications, they are more expensive than regular seeds.


Regular Seeds:

Regular seeds require little to no modifications and cross-pollinate to produce approximately 50% male and 50% female offspring. The plants show their sex after flowering, so regular seeds are not the best option if you only want female seeds.


However, regular cannabis seeds are cheaper and are the best for breeding rather than yielding buds. Moreover, the cross-pollination that occurs with regular seeds facilitates the production of random new genetic profiles. Therefore, regular seeds can potentially produce more resilient plants thanks to their unaltered genetics and save you money on buying seeds in the future.


Feminized Seeds:

Feminized marijuana seeds are your go-to seeds when you want to harvest thick buds that feature a rich resin profile. As the name suggests, feminized seeds undergo modification to remove the Y male chromosome and only retain the X female chromosome. So, feminized cannabis seeds self-pollinate and produce flowers, but they do not produce seeds.


Unlike regular female seeds pollinated by male seeds, feminized seeds do not produce seeds. Instead, they focus all their energy on growing luscious buds and developing rich resin, terpene, and cannabinoid profiles.


Note that cannabis cultivators avoid male seeds because such seeds pollinate female plants, causing seed-riddled buds. Seeds are a nuisance in cannabis buds, so feminized seeds are best for consumable cannabis forms.


Due to self-pollination, feminized seeds retain the genetic integrity of the “mother plant.” Feminized seeds can also undergo photoperiodic modification and become auto-flowering feminized seeds which are quite easy to grow and feature a high yielding rate. These seeds are also pricier than regular seeds in terms of costs and can cost more than auto-flowering feminized seeds. However, they are not ideal for breeding.


How to determine the quality of the Cannabis Seeds

Not all cannabis seeds are viable for germination, and planting duds will cause you disappointment when they fail to germinate. Therefore, it is prudent to examine your seeds for viability before commencing the germination process. Use your senses of sight and touch to check the following factors and establish seed quality.


  1. Hardness -A viable seed has a firm, smooth outer shell. Avoid seeds that are brittle or shriveled. Squeeze the seeds with your fingers and get rid of those that crumble and crack easily. You should also ensure that the seeds do not have any holes or cracks as these are indicators of pest infestation; the pests probably ate the embryo.
  2. Size- different marijuana strains produce seeds of various sizes. Some strains have small-sized seeds but produce quality harvests. Seeds that are too tiny, however, have a low germination success rate. Those with the most symmetrical round or teardrop shape are also the best quality.
  3. Color- Healthy and viable cannabis seeds feature a dark color, mainly black and deep brown shades, and a glossy sheen akin to well-polished furniture. Some viable cannabis seeds may also feature tiger-like stripes on their shells.


However, watch out for light green and grey seeds during your inspection; such seeds are premature and are highly unlikely to germinate. Even if they germinate, they will yield low-quality crops different from what the seed bank promised.


NOTE: Cannabis seeds are pretty sensitive, so refrain from applying enough force to crush the shell of healthy viable seeds. The seeds are also sensitive to physical touch. For this reason, use latex gloves during the physical examination to preserve their integrity and prevent microbe contamination.

Cannabis Seeds
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Germination Guidelines

As earlier mentioned, cannabis seeds are quite sensitive and need optimum growth conditions to survive. Therefore, pay close attention to the following desirable ambient conditions to achieve the best germination rates.


The ideal germination temperature ranges from 22◦C to 25◦C (71◦F to 77◦F). Cannabis is a seasonal plant, and in a natural setting, the seeds usually germinate in the springtime. Therefore, attempt to replicate the springtime weather by striking a balance between hot and warm temperatures.


To help keep the germination area warm, you can apply the same principle in hatchery incubators and utilize incandescent bulbs. Incandescent bulbs may not emit the light intensity necessary for a germinating seedling, but they can generate warmth.


However, if you choose to go with incandescent bulbs, ensure that only the warmth but not the light reach the seedling. Besides incandescent bulbs, you can use a heating pad or heating mat to regulate the germination temperature if you live in colder climates.


Although cannabis plants need light for growth, they need darkness to germinate. Even if you choose to germinate your plant indoors, you need to replicate nature’s way whereby the seeds germinate while covered by soil. Therefore, regardless of the germination method you choose, ensure to keep the potential seedling away from light until the root pops and the seed is ready for a transplant. Find out more about the types of cannabis germination methods in the next segment.


Germination requires a relative humidity between 70% and 90%, so water your seeds but be careful not to leave your germination medium wet or soggy. A soggy growing medium presents water stress to the germinating seed, so the seed reacts by producing the abscisic acid enzyme.  Abscisic acid is a hormone in plants that promotes dormancy in plants during unfavorable growing conditions and hampers plant growth, including germination.



One way to maintain the optimum humidity level stated above is to set a timer and spritz your potential seedling with some water at regular intervals. Second, also note that soaking the seeds for too long can damage them.



On the other hand, when the first root breaks through the shell and finds no water, it will die, so while less is more, don’t be stingy either. It would be best if you continually kept the roots moist to maintain a conducive environment for germination.


You should always minimize the amount of seed handling. Leave the seeds alone while waiting for the taproot to emerge and when you have to move them, do it gently. Avoid touching the taproot as it is delicate and can snap off easily, so savor the excitement with your eyes only.


Seeds germinated indoors have a higher chance of survival compared to seeds germinated outdoors. The difference in germination rate is because the fragile seedlings become exposed to the harsh weather, pests, and mold when you grow them outdoors. Any stress to the seedlings arising from the above factors may cause the seeds not to germinate and cost you significant financial loss.


However, you can soak your seeds in 1% hydrogen peroxide or compost tea for 12 hours in advance to kill any dangerous pests. You can also use alcohol to disinfect all materials that touch the seed, such as plates, glasses, and towels.


While germinating cannabis seeds, work quickly and accurately. Working faster will reduce exposure and thus the chances of pathogens such as white, black, blue, and grey molds infesting your seeds.


Methods of Germination

As previously stated, there are different methods cannabis cultivators employ to germinate their seeds. However, the optimum germination conditions discussed above hold for all germination methods. Below are the four main cannabis germination methods, along with their pros and cons.


Using a Glass of Water:

Follow these easy steps:

  1. Fill a glass three-quarter full with distilled lukewarm water that also has a neutral pH reading. Avoid water with fluoride since it is alkaline and, in certain concentrations, may alter the water’s pH and potentially become a stress factor for the seed, impeding germination.
  2. Drop some seeds into the water; the seeds will float for a few hours then sink to the bottom. Keep the soaked seeds in a dark place with a temperature of 19 to 25 degrees Celsius.
  3. Refresh the water regularly to prevent the seeds from rotting before germination.
  4. Let the seeds soak for 12 to 8 hours. Gently tap the seeds with your finger to ensure they sink to the bottom. If they don’t, you can give them time.
  5. Transfer the seeds once the shell breaks and a root emerges.
  6. Allow the seed’s emerging taproot to grow to at least half a centimeter to three-quarters of an inch lengthwise before transplanting the seed.

NB: While using water is the simplest way to germinate cannabis seeds, it bears some significant concerns. The downside of this method is that exposing your seeds continually to moisture may cause them to rot or develop mold rather than germinating. Consequently, cannabis cultivators are abandoning this germination method for more effective and less risky germination methods.


The Wet Kitchen Towel Method:

The paper towel is one of the simplest and effective ways of germinating cannabis seeds. It entails using paper towers as the germination medium for your seeds; the cost-effective medium is part of what makes this germination method popular. However, ensure that you use single-ply paper towels rather than cloth towels as the latter may cause the roots to grow into the cloth.


  1. Moisten the paper towels by spraying water on them. Allow the excess water to drip off and place the towel on a plate.
  2. Put a few seeds on the towel and cover them with another damp towel. Cover the entire setup with another plate to create a dome shape.
  3. Keep the seeds warm by using a seedling heat mat. The seeds do best at a temperature of 70 to 80 degrees Fahrenheit. To avoid overheating when using the seedling heating mat, use a separator between the plate and the heating mat.
  4. Regularly check the setup to ensure that the paper towels do not dry up.
  5. Once the taproot emerges, use a pair of tweezers to pick the seed up while ensuring the roots do not tangle up on the paper towels. Using tweezers prevents you from contaminating the delicate seedlings and causing physical damage to the highly delicate emerging taproot.


Planting Directly in the Growing Medium:

Planting seeds directly into the soil or coco coir is the easiest germination method. The soil protects the fragile roots of a germinating seed from interference. It also causes minimal stress to the germinating seedling; stress factors for germinating seeds include extreme temperature, humidity, light, and the wrong pH level.



  1. Commence germination by making a hole about a centimeter deep with your finger in the growing medium and place the seed.
  2. Water lightly as a strong stream of water can dislocate the seed.
  3. Provide the seed and the sprouts with a constant temperature of around 20 to 25 degrees Celsius (71 to 80 degrees Fahrenheit).

Note: Do not add more nutrients to either the water or the potting soil to avoid the risk of overfeeding and killing your seeds.

Use Starter Cubes and Seedling Plugs:

The use of starter cubes and seedling plugs is one of the easiest methods of germinating cannabis seeds. Starter cubes and seedling plugs have holes in which you place seeds, add water and pinch the top to close. They have all the conditions for germination and don’t leave room for error. Some types of starter cubes for germinating cannabis seeds include;


Rapid Rooters

  • Pour water into a container to hold the rapid rooter plugs.
  • Place the seed on the hole on top of the cube and put it in a humidity dome.
  • When the seeds sprout, transfer them using tweezers.
  • Use the sprouts on hydroponic setups or soil.

Rockwool Cubes

Rockwool cubes are primarily used in hydroponic setups.  They have a pH of approximately 7.8, which is not conducive to the germination of cannabis seeds.


  • To make them favorable for germination, soak the cubes in some pH-adjusted water.
  • Insert the seed in the cube and let it germinate. Minimize handling of the setup to avoid disturbing the process of germination.
  • Only adjust pH and place the seed inside the cube (Rockwool cubes contain all the conditions for germination).


NB:  There are health concerns associated with using Rockwool cubes, and you should use protective gear when handling them. It is also not good for the environment because it is non-biodegradable.

Peat Pellets:

Peat pellets are anhydrous peat discs that are compressed into a biodegradable mesh.

  • Moisten the pellets while avoiding adding too much water. You should also avoid covering it too much, which can increase the chances of fungi growth.
  • Place one seed in each peat pellet about a centimeter deep and transfer them once the first root pops out.

Germinating Cannabis Seeds
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Transplanting Germinated Cannabis Seeds

The best time to transplant the germinated seed into the growing medium is once the taproot is a few millimeters in length.



  • Start by making a hole one centimeter deep using a pen or a finger in the growing medium and make it twice as deep as the seed is wide.
  • Water the soil before putting the sprout into the hole. The soil should be damp. Use a pair of tweezers and gently pick the seedlings up while ensuring the seeds don’t cling on the cubes or the paper towels.
  • Drop the seed in the hole with the taproot facing down. Take care not to touch the root. The root should face downwards in the growing medium to prevent the seedling from reorienting itself, slowing down growth.
  • In the next few days, use a spray bottle to water the seedling. Using a spray bottle to water will prevent the oversaturation of the soil, which can kill the delicate sprout.


Once plated, closely monitor the temperature and moisture levels.

How to Store Leftover Seeds

Premium-quality cannabis seeds are quite pricey, so you do not want to dispose of any viable leftover seeds. Fortunately, with proper storage, you can store cannabis seeds for as long as ten years. They preserve the integrity and viability of your leftover seeds until the next germination season comes around.


Note that the period over which you intend to store the seeds dictates the appropriate storage containers and bags to use. So, if you want to store them for just a few months, keep them in a zip lock bag, a glass jar, or any other airtight container. When storing for more extended periods, use a vacuum-sealed package.


Alternatively, you can store the seeds in the freezer for long-term storage. If you decide to freeze the seeds, keep them as far as possible or use a less busy fridge to avoid temperature fluctuations as the fridge door closes and opens repeatedly. Temperature deviations can damage the genetic integrity of the seeds.

Cannabis Seedling
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Where to Buy the Best Cannabis Seeds

Your Local Dispensary:

Many companies sell cannabis seeds in US states where recreational marijuana use is legal. The seeds vary in quality.


Some states allow home growing for medical and recreational use. It is easier to find dispensaries and seedbanks that sell cannabis in these states. Every state has its laws regarding cannabis, and you should familiarize yourself with the regulations.


In California, medical cannabis users can obtain seeds from cannabis plants grown in the state. To get quality seeds, ensure that you buy from established companies with great reviews. Always keep in mind that the highest quality seeds are not the cheapest. Buy from a company that has a reputation for quality.


Online Seed Banks:

There are international seed banks that ship to the United States. You can also buy the seeds online from another state. However, you can get in trouble with the customs as the laws are confusing. However, some banks like the sensi seed bank will send you another package for free if the Customs confiscate your seeds. You can face repercussions in some states that don’t allow home-growing of cannabis.  There are seed banks that do stealth shipping to avoid detection by Customs officers.


You should also be extremely careful about purchasing seeds online. Fraudulent vendors can take your money without sending your seeds or send you things you didn’t order. Transparent vendors have all the information on where they ship on their websites.


Final Thoughts

The quality of your cannabis seeds, the storage practices employed while preserving them, and the process you use to germinate the seeds directly affect your germination rates. With all the vital information about cannabis seed germination, you can now start growing your cannabis.

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