Germinate Weed Seeds In Light Or Dark

Discover the most effective ways of germinating cannabis seeds indoors in an easy, fast and affordable way; the best tips and tricks. A step-by-step guide describing the best way to germinate your cannabis seeds. This germination method is ideal for the indoor and outdoor grower. There are many to consider when germinating cannabis seeds — not only the germination method you choose but also the conditions your seeds require to thrive.

Germinating Cannabis Seeds – Different Methods

A seed is a plant that’s waiting for the right conditions to germinate and grow. This post is designed to teach you how to germinate cannabis seeds as efficiently as possible in order to obtain successful results during this delicate phase.

Table of Contents

Cannabis seeds (or marijuana) germinate when they’re in the right conditions for successful growth. In nature, this process occurs on its own around springtime; moist soil begins to heat up with the increased sunlight and the inclination of the earth. We’re going to give a quick overview of the different methods used when it comes to germinating cannabis seeds.

Under these conditions, seeds germinate in soil protected from direct light and in an airy substrate. Once they’ve germinated they will begin to take root in the soil.

  • Humidity: alongside heat, this activates seeds and softens the protective shell. Once the seed has germinated, it will need moisture to survive.
  • Darkness: roots are incredibly light-sensitive, so they’ll need to be in the dark in order to guarantee germination.
  • Heat: alongside humidity, heat activates seeds and indicates that the conditions are right to begin growing. It’s important to maintain temperatures between 20 and 26°C during the germination process.
  • Oxygen: it’s important to periodically open the container in which you’re germinating your seeds in order to renew airflow and give your plants’ seeds more oxygen.

How to Germinate Cannabis Seeds

There are many different germination methods when it comes to cannabis seeds, from simple to complex processes. In this post we’re going to go through the most common methods used that, when done with a care, can be 100% effective.

Germinating Cannabis Seeds in Paper Towels

Germination in paper towels is La Huerta Grow Shop’s preferred and recommended method due to how efficient and easy it is, as well as being the cheapest method. Cannabis seeds ready to germinate in paper towels

Necessary Materials
  • Absorbent paper towels (kitchen)
  • Two plates or plastic, opaque Tupperware with a lid.
  • Water.
  • Sprayer (optional.
  • Seeds
  • Latex gloves.

We highly recommend using latex gloves during the entire process in order to avoid accidental contamination via fungi or virus.

You can also use Germinator Pro to help you with this process; it comes with everything needed for the germination process, including a thermometer on top of the germinating container.

Steps to follow
  1. Place 6 – 8 paper towels on a plate or in your Tupperware, and pour in small amounts of mild water until they’re covered. Squeeze them softly until they’re moist but not soaking.
  2. Place the seeds on the paper towel “pillow”, keeping them a distance a apart so their roots don’t end up intertwining. The less you touch them with your hands, the better.
  3. Wet another 6 – 8 paper towels, squeeze to remove excess water and place them on top of your seeds.
  4. Place the second plate upside-down on top (or the Tupperware lid) in order to guarantee darkness. You can close the lid entirely or not, depending on how fast the paper dries. Keep in mind that you need to keep the paper towels moist until the last seed germinates. If you close the lid fully, open it once a day to make sure they get more air and to check if they’ve germinated.
  5. Place the seed container in a warm area without direct sunlight, keeping the temperature between 18 and 25°C. At La Huerta Grow Shop we’ve noticed that cannabis seed germinate faster and better when placed over very light heat sources like a router or on top of the fridge, which generate high enough temperatures to stimulate germination.
  6. Observe the process and maintain humidity. If the paper dries up, spray it again until it’s moist. Seeds don’t always germinate at the same time, so we recommend transplanting when the root is between 1 and 15 cm. If you leave germinated seeds in the container for too long, the root may grow too long and make them harder to handle. This initial root is highly delicate; we recommend using latex or plastic gloves.
  7. Transplant your seeds. You’ll need to wash the soil and make a hole as deep as the root; place the seed in with the root facing downwards. This allows the first two leaves to sprout above the surface of the substrate. The substrate should be moist – not soaked – until the plant grows its first pair of real leaves. During this delicate phase, the amount of moisture available is crucial; don’t let it dry out too much, but don’t over-water. We recommend using small amounts of water frequently.

*if you’re using a heater or heating mat, keep in mind that your seeds are in a container and not a flowerpot, so the heat may be excessive.

How to Germinate Cannabis Seeds

Germination is the beginning of your cannabis seeds’ life and is easy to master. At this crucial stage, seeds grow and sprout into young seedlings. The best genetics deserve the best start, and all you need is two plates, some paper towel, and water. Apply the best germination method today and enjoy a great harvest.

1. Germination set-up

Prepare the first plate by lining the inside surface with two to three layers of damp paper towel. Drain excess water from your plate.

Place cannabis seeds on the top surface of the damp paper towel. Approximately three per plate; ensure they are not touching but are evenly spaced apart.

Add only a few layers of damp paper towel on top of the seeds, and let any excess water drain from the plate. Too much water lowers the chance of successful germination.

To complete the set-up, place the remaining plate upside-down and on top of the first plate, resembling pearls inside a clam.

2. Germination

Cannabis seeds need a dark, warm, and humid atmosphere to germinate.

Around 21°C (70°F) is perfect. Check the paper towels every second day and if required, spray with water to keep conditions moist for your seeds.

After a few days, tiny roots will begin to emerge. Congratulations! Your seeds have survived their first stage of life. Don’t worry if some of your seeds have not yet changed, they may just need a little more time as germination can take up to 14 days.

See also  Throwing Weed Seeds Outside

3. Plant of the seeling

Once the roots are a few millimetres long, they are ready to be delicately transferred to a small container filled with your growing medium of choice (rockwool, coco-fibre, or soil).

Make a hole in the growing medium that is 2 – 5 mm deep. Use tweezers or your fingers to transfer germinated seeds gently into the hole (root pointing down) and lightly cover with a fine layer of your medium. Do not pat it down too hard. The stem and the first tiny set of leaves, called cotyledons or ‘seed leaves’, should begin to emerge 24 to 72 hours after the seeds are planted.

4. Supplying a light source

Seedlings must be exposed to sunlight once they sprout. Ensure this is a gradual process as too much heat causes stress and will stunt growth.

Find a sunny place where you can begin to increase sun exposure, such as a windowsill. Ensure sun exposure is increased by an hour or so a day.

For an indoor plant you can use a fluorescent light (keep normal distance from bulb) or HID lighting (50-80 cm from the bulb).

Take care in the first week or two, as seedlings are still quite delicate and sensitive to the elements. They won’t need a lot of attention until the vegetative stage so avoid overhandling.

Germination is the beginning stage of the growing cycle, and this easy-to-follow guide gives your premium genetic cannabis seeds the best start to life. Whether you are a first-time home grower or a well-seasoned gardener, share your experience or any questions in the comments down below, as well as your tips and tricks!

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Comments

22 thoughts on “How to Germinate Cannabis Seeds”

Hi, Once seeds have sprouted, how long can or should you leave them to grow under 24 hr lights before moving to your outdoor garden?

Good afternoon Ken,

I hope you’re having a great day.
For the vegetation process, a light schedule of 18 hours of light, and 6 hours of darkness is preferred. Many growers get plants acclimatized to outside by placing them in a window, or under direct sunlight for a few hours a day.

Thanks again, and have a great day!

Hello everyone, all these suggestions are wonderful but I think a lot of you make it sound a little overwhelmingly. I’ve been very successfully cultivating for decades and I’ve always just placed my seeds, be it 1 or 100, in between 2 folded sheets of tissue which I’ve made wet with tap water. I then place them on a tray or plate in a warm dark area , such as an airing cupboard and leave for how ever long they take usually, 12 to 24 hours. The ONLY thing I do which takes effort is PH balance the water I germinate them in and I’ve only lost 5 seeds in nearly 40 years .

Good afternoon Paul,

I hope you’re having a good day,
Thanks for sharing your experiences with germination. pH balancing is a great tip You also might be interested in our new Jamaican Pearl Feminized Grow Report

Thanks again, and I hope you continue to enjoy the blog,

I lightly score my seeds by shaking them inside a rolled up piece of sandpaper – sandpaper side on the inside before leaving them in a cup of water for a few hours to hydrate. I then place them between wet (good quality) paper towel per instructions above. I find using an old plastic takeaway container with a heatmat below keeps the humidity high and with good end results.

Good morning Jonny,

Thanks for sharing your methods for germination with us, the heat mat and low-humidity are great tips!

Thanks again, and I hope you continue to enjoy the blog,

I have found out that the best and fastest way is to take a glass of clean/filtered water and place the seed right on top of the water (floating – NOT immersed in it!). If the seed is viable it will sprout in no more than 48 hours. Right after that you plant it in your pot/soil etc and you’re done.

Good morning Mary Jane,

Thanks for your support, and for sharing your experiences with germination!
You might also be interested in our article on The Life cycle of Cannabis: From seed to harvest.

Have a great day!

What happend if they sink I had em sink they came out fine

Are you saying they sprout in the glass of water and don’t “drown”?

Take aluminum foil flatten it out and put on top of your dirt it detects planes and grow it just like a tomato plant

Good morning Tammy,

Thanks for getting in touch with Sensi Seeds, and sharing your germination method with us!

Thanks again, and I hope you continue to enjoy the blog.
With best wishes,

Detects planes? Like magnetic? I’ve always has best success 24-48 hours soaked In water, spring water if possible. Usually do this in a shot glass, once they pop I’ll take a paper towel fold so it’s 2 layers then fold once more so you know where center is. Dump the seed in the middle of the edge and the true center (reason we folded a 2nd time)as well as the water just enough to saturate the paper towel. Do not soak! Carefully with the seed in the middle using sterile tweezers turn so the tap is growing down. This will prevent circling and tangling if doing multiple seeds. Now you can fold the other half so your seed will be “sandwiched” between 2 layers. At this time carefully take a corner and the waters attraction should keep your paper towel from unfolding but just in case be gentle. Holding it from 1 corner you can dangle it over a cub or the original shot glass so any extra water runs off. Now take a standard zip or press n seal sandwhich bag and slide your napkin in Carefully . REMEMBER which way was down! Work the air out making jt flat snd seal. Find a temperate dark area around 70°. A cabinet works we’ll as your going to prop it up with taproot facing downwards. Now just close it up and wait in 24-72 hours checking once a day. In rare cases you could have a 1/2″ tap root in the first 24 hrs some may take 4-5 days. Once the tap is about 1/2″-3/4″ long its ready for transplant into its first small pot. With this paper towel method I typically have 100% success.

See also  Planting Weed Seeds Straight Into Soil

Can you leave your seed to develop longer roots in the germination phase and can this make them better to grow or is a big no no?
Last year, I had 2 seeds that had really long roots with lots of secondary roots coming out when they were planted, one of which died after a couple of weeks and the other grew into a huge plant.
The other two seeds only had a short germinated growth and both died almost immediately after planting so not sure what I can learn from this…lol

Appreciate any thoughts and advice

Unfortunately, legal restrictions mean we can’t answer grow-related questions or give grow advice on this blog. However, other readers of this blog will often answer questions like yours.

Please check out the following articles on our blog which I think you may find of use, and I hope you continue to enjoy the blog!

With best wishes,

How often do you water and how wet should the plant be? Please.
Also if they are outdoor plants do you need to keep them covered with clingfilm for a wee while or do you just hope for the best. Thanks

This article, about how to water cannabis plants, should answer your questions. I can’t help you with the clingfilm one though, as it depends on the climate. Good luck, and happy gardening!

With best wishes,

Just drop the seeds in water, they will sprout , don’t have to use a towel and check it all the time , drop it in the water , let it float then it will sink and the root will grow out ,let the root get 1/4 inch and plant it where it’s going to grow , 8 hours sunlight starting as soon as it is out of the soil. Always grows great , don’t have to transplant from cup to gallon to bigger and bigger , if it’s growing outside put it where it stays , always does just fine.

Good afternoon Graham,

Thank you so much for sharing your experiences with germination.

Thanks again for your comment, and I hope you continue to enjoy the blog.

Have a great day!

I recommend this article to all breeders and cultivators who plans to germinate seeds and to some who don’t know how to germinate seeds, this article has the best and perfect ways on how to do it.

I have large bay windows at my condo which get about 11-12 hours of light per day. They are tinted but warm. I grow other indoor plants there perfectly. Is an ok place for my pot plants?

This sounds like a great place for all kinds of plants! I recommend you have a look at autoflowering varieties, as otherwise light pollution may negatively affect the flowering cycle. Good luck, and happy gardening!

With best wishes,

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Care and Caution When Germinating Cannabis Seeds

For growers looking to produce top-shelf cannabis, it all starts with the seeds. Rich Hamilton explains there’s far more involved than simply burying a seed in a pot of dirt.

There are many to consider when germinating cannabis seeds — not only the germination method you choose but also the environmental conditions your seeds require to thrive. These conditions include temperature, light exposure, moisture, and oxygen levels. Get any of these wrong and it could spell the end for your grow before it even begins.

Cannabis seeds can be very delicate and temperamental even when germinating in the perfect conditions. You can understand why you should approach this task with best-practice knowledge and caution.

To try and give your seeds the best chance, we are going to look at some tips and methods to help you get better results, first time, from your germination efforts.

Firstly, what is germination? Well, germinate means “to bring to life.” Germination is the first part of a plant’s life, the growth or shooting of a seed into a seedling and then hopefully a plant.

Cannabis seeds germinate via epigeal germination which sees the cotyledons (seed leaves) pushed upward and out of the soil as the plant begins to grow. For germination to occur, several natural elements and conditions must be present in the correct ratios. Let’s have a look at them.

Water — This is needed to start the germination process as the seed is dry, holding only five percent water and needs to absorb a lot more to begin the germination process. Seeds store starch, oils, and proteins and when germination begins, hydrolytic enzymes are activated, releasing the stored supplies and giving the plant just enough of the right chemicals to get it started. Water is also needed to expand the seed’s shell and soften it, allowing it to split for the beginnings of the plant to emerge. The hardness of a cannabis seed shell can vary quite a lot. If your seed is ripe and mature enough for germination, then you shouldn’t have any problems. A more immature cannabis seed, however, will have a more rigid shell and may fail to germinate.

Oxygen — Seeds need to breathe, but without oxygen the seed may drown or suffocate. Overwatering can suffocate your cannabis seeds preventing oxygen from getting to them, so keep them moist but not soaked. Don’t overwater your seeds — use a spray mist rather than pouring water directly onto them.

Temperature — Ideally, your cannabis seeds will germinate best at their “sweet spot” between 70-75°F. If you germinate a cannabis seed outside this range, then it can negatively affect the plant’s growth and health in the future. When temperatures are too cold, it can ultimately stunt germination so keep seeds away from any drafts, open windows, or fans.

Light conditions — Cannabis seeds germinate best in dark conditions. During germination, your cannabis seed is working to develop its first root (the radicle), and roots (unsurprisingly as they exist underground) do not like light! It is therefore vital to keep your cannabis seeds somewhere dark until transplant. But as soon as germination occurs and your new seedling develops leaves, it will need to be exposed to light to start the vital task of photosynthesis. Now that we understand what your cannabis seeds need, let’s explore the most popular methods used to germinate them.

See also  Seed To Harvest Weed Plant

The Glass of Water Germination Method

You can leave your cannabis seeds in a glass of mineral water in a dark environment until the radicle/tip of the root shows.

Depending on the seed strain, you should generally see something happening within one to five days. Why mineral water? Well, depending on where you live, your tap water can vary immensely in terms of chemical composition and pH. The ideal pH for water when germinating is pH 7. Anything outside of this can have adverse effects on your seed. Using mineral water is a cheap and effective way of keeping a stable pH environment. If you use tap water, however, leave it to stand for 24 hours first. The tap water needs a chance to settle and dissolve any chemicals that are present and may be harmful to the seeds.

You can use an air stone and pump to oxygenate the water whilst it stands for 24 hours. By doing so, you will reduce the chance of the seeds drowning and helping to dissolve any unwanted chemicals at a faster rate.

The Paper Towel Germination Method

Using a paper towel to germinate your cannabis seeds is both reliable and straightforward. You should find that 90 percent or more of your cannabis seeds will germinate when following this method correctly.

Take a sheet of premium paper towel and fold it in half, then place the seeds to the left of center. If you are germinating more than one seed, then you can use the same piece of kitchen towel but do not let the cannabis seeds touch each other. Now fold the kitchen towel in half again so all the seeds are covered up and then saturate it with water.

Mineral water is excellent to use, or if you are going to use tap water, then follow the recommended process for the glass of water method as previously discussed. Now leave the kitchen towel on a plate in a dark place as the roots will hopefully begin to develop soon and they do not like the light.

Humidity levels are equally important and keeping the seeds in the paper towel will keep the humidity levels where they should be. Keep the kitchen towel moist at all times and do not let it dry out. If you have been successful, it should take about two to four days for you to see until the radicle begins to emerge.

It is best practice to place the moist kitchen towels between two clean plates. Doing so helps to stabilize temperature and humidity and block out any light. The plates should be face-to-face, with the germination towel in between. Once a cannabis seed starts showing signs of successfully germinating, you can easily remove them whilst leaving the others, which may not yet have germinated, undisturbed.

Direct Germination Method

Germinating “directly” is where you place the cannabis seed directly within a pellet or block of a medium of your choosing. You can germinate your seed within a soil or coco pellet, however, I would recommend choosing a one-inch rooting sponge or stonewool cube.

You can use a soil pellet, but the risk here is that soil already contains a certain level of minerals and elements that could cause an imbalance in your seed, affecting its development later on in life.

For seeds in their natural environment, there can be double, triple, or a hundred times more plants growing in the soil at any one time. From those plants, thousands of seeds are dropped for germination and of those thousands, only half may germinate, even under natural conditions.

We are trying to grow our seeds under controlled conditions and in much smaller numbers. The margin for error, therefore, is much smaller. Using a rooting sponge is an excellent alternative for germination as it eliminates any risk of deficiencies or toxicities you may otherwise experience when using a natural medium such as soil at this early stage.

The direct method of germination can be hard to control as you must wait until the seedling first shows itself out of the chosen medium to know whether it has been successful or not.

As the cannabis seed is buried within its medium, you cannot check on it during the process to see if it has begun the germination process. As a result, this process can take much longer than the methods already discussed.

If you are germinating “directly” then firstly you should moisten your medium by misting it with a spray bottle. The cannabis seed will then need to be carefully inserted into the chosen medium and be surrounded by its encasing environment to keep any light out.

Now that you have chosen your method and you have successfully germinated some seeds. What now? How do you know when you should transplant? If everything goes according to plan with your germination efforts, you will see the radicle/root tip of the cannabis seed breaking through the shell. This new root is the first sign germination has occurred. It is best to transplant each seedling when the radicle is around three times the length of the seed.

A rooting sponge is a perfect choice for transplanting as it is compatible with whatever medium or system you use later. Rooting sponges are also an excellent choice for those who are looking to sell their seedlings.

Rooting sponges and stone wool blocks make for more robust root systems. It can take longer for the roots to break through, but when they do, they will be stronger.

When you are transplanting the seed, it must be placed radicle first into its new home, quickly, gently, and precisely as it only has a minimal amount of energy to survive and develop into a seedling. Once your seeds are transplanted, they should go into a propagator, ready for the start of the growth phase of their lives. Your cannabis seed holds all the potential to give you the vibrant, robust, healthy plants, and bountiful yields you desire.

Taking the time and care to get your seeds off to a good start should be a no-brainer. Knowledge is power if you want to be a better grower, so think of the learning process just like a seed itself. Nurture it, cultivate it, and you will soon harvest success.