A step-by-step guide for successful cannabis germination grounded in science. Reviews strategies for germinating cannabis seeds and offers tips for success. 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. Discover the most effective ways of germinating cannabis seeds indoors in an easy, fast and affordable way; the best tips and tricks.
Germinating Cannabis Seeds – A Step by Step Guide
Germinating cannabis seeds is one of the most exciting parts of the whole grow. It is almost magical to summon new life from a dormant seed; however, it can be very frustrating when things don’t go well. In this article, I explain how to germinate cannabis seeds successfully. I begin by reviewing the science of germinating cannabis seeds. I then describe several common cannabis germination strategies and share some cannabis germination tips and tricks. At the end of the article, I provide my step-by-step guide to germinating cannabis seeds. Be sure to watch my Germination Tutorial on YouTube!
Germination will always be exciting, but it does not need to be intimidating. There are many ways to germinate cannabis seeds successfully. Understanding the science and the shifting needs of the developing plant will allow you to choose the germination strategy that is right for you.
The Science of Germinating Cannabis Seeds
Cannabis seeds are among the easier seeds to germinate. They are large dicotyledon seeds that store a reasonable amount of energy for early life. Furthermore, cannabis seeds do not have any significant seed dormancy factors to overcome. If they are viable seeds they will germinate easily when exposed to the correct conditions.
Seeds become Sprouts During Germination
This may sound obvious, but it is important to consider because seeds and sprouts are different. When the cannabis seed is still a seed, it is resilient and does not depend on ideal conditions to survive. However, sprouts are different. As soon as the seed cracks open and exposes the radicle (tip of the root) it becomes a sprout. As a sprout, it becomes much more sensitive to external conditions. Whereas the seed only needs warmth and moisture to germinate; the radicle on a sprout needs warmth, moisture, oxygen, and darkness to survive and grow.
Germination Stage 1: Imbibition
The seed’s journey to planthood begins by getting wet which starts the process of imbibition. Imbibition is similar to rehydration. When wet, the testa or seed coat of cannabis seeds imbibe water which causes them to swell and soften. The force of water entering the cells in the testa physically ruptures the seed coat and allows the radicle (root tip) to escape. The imbibition of water also activates the metabolic activity within the seed protoplasm.
Warmth is Required for Metabolic Activity
The metabolic activity within the seed will only activate if the temperature is in the appropriate range. Like other seeds, cannabis seeds will not successfully germinate if the temperature is too low or too high. Room temperature is warm enough to allow germination, but warmer temperatures enable more metabolic activity and faster germination. The ideal temperature range to germinate cannabis seeds is 80-86 F (27-30 C).
Germination Stage 2: Respiration
Seeds carry stored energy to help power metabolic activity and growth until the plant can begin photosynthesis. However, just like humans and other animals, plants must engage in respiration in order to convert that stored energy into active energy that the plant can use. During the earliest stages of metabolic activity as the seed awakens from dormancy, the respiration is anaerobic or without oxygen. However, the sprout needs to quickly begin using oxygen in aerobic respiration to continue to survive and grow.
As metabolic activity resumes, the sprout will begin to grow. Cannabis seeds store most of their energy in their cotyledons in the form of starches and proteins. The plant uses energy from aerobic respiration to digest these starches and proteins into simple sugars and amino acids, which it mobilizes to grow the radicle (root tip) and hypocotyl (stem).
Cannabis Sprouts need access to both water and air
Seeds can be completely submerged in water during the first part of imbibition. However, if they are completely submerged after the radicle is exposed then the sprout will die from lack of oxygen. As soon as the seed cracks open and exposes the radicle it needs to have access to oxygen for aerobic respiration. This means that it needs some contact with air. However, it also needs continuous contact with water. To achieve the best results in the sprout and seedling stages it is best to use a grow media that will trap both air and water. As I explain below, paper towels work well for this during the early sprout stage and germination media like Jiffy Pellets or Rockwool cubes are perfect for young seedlings.
Germination Stage 3: Orientation
At this stage of germination, the plant must orient itself to grow properly. The radicle must push down into the soil or media and the hypocotyl must push the cotyledons (first leaves) up out of the soil or media. Both gravity and light help orient the plant to grow in the proper direction.
Apply Light but Keep the Radicle in the Dark
Cannabis seeds do not require darkness to germinate. However, the radicle is sensitive to light. Bright light will stunt the radicle and can lead to a failed germination. When seeds are germinated in paper towels it is best to keep the sprout in total darkness until the radicle is about half an inch long (about 1.25cm). However, as the cotyledons emerge from the seed casing, they will be looking for light to indicate the direction they need to grow. Therefore, when the radicle is longer than half an inch it should be placed in media which will protect it from light. Once the radicle is safely in the media, light should be applied to the top of the media to signal the direction of growth for the cotyledons.
Germination Stage 4: Photosynthesis
During the germination stage the plant relies exclusively on stored energy from the seed. This energy is limited, so the plant must quickly begin producing its own energy through photosynthesis. The young plant works to establish its radicle in the media and push the cotyledons up into the light to begin photosynthesis. Once the cotyledons open and receive light, the plant will begin photosynthesis. At this point, germination is complete, and the plant can start producing its own sugars, starches, proteins and fats.
Nutrients for Germinating Cannabis Seeds
The nutrients and supplements that we provide to our plants are not their food. Nutrients and supplements support photosynthesis. Therefore, they are not needed until the plant has begun photosynthesizing. Indeed, adding nutrients to the water used for imbibition can actually inhibit germination. It is best to use plain water at a neutral pH (7.0) to imbibe the seeds.
Once the cotyledons are open, the plant can use very small doses of nutrients. However, it is easy to overdo it and burn the plant. When and how to begin fertilization depends largely on the media that you are growing in. If you are growing in coco or other inert and unamended media, be sure to read “How to grow cannabis seedlings in coco coir”.
Cannabis Germination Strategies
There are many viable ways to germinate cannabis seeds. Different germination strategies may be more suitable for different growers. Therefore, before explaining my step-by-step guide to germinating cannabis seeds, I will review some of the more popular germination strategies.
Many growers begin germination by soaking seeds in water. This allows for faster imbibition of the seed because it is surrounded by water. It is a safe strategy to follow as long as you remove the seeds from the water before the seed actually cracks open. If you soak seeds, you should use plain (low EC) water with a neutral pH (7.0). Filtered or distilled water is best.
The Paper Towel Method
This seems like a make-shift hack, but wet paper towels provide an excellent air/water ratio for germinating seeds. They also allow you to precisely control the temperature of the seed/sprout during germination. As a result, using paper towels can speed the germination process considerably.
The paper towels should be fully saturated with water, but not dripping wet. I like to fold the paper towel so that there are two layers below and above the seed. You can then place the paper towels in an air-tight container to prevent them from drying out. I use pyrex containers. If you use a plastic bag, just make sure that you trap some air in the bag (don’t squeeze all the air out). The radicle does need some air, but there will be plenty, even in a sealed container. Place the sealed container someplace warm and cover it to protect the radicle from light.
The main drawback to the paper towel method is that it is possible to damage the young sprout when you transfer it to media. There are some easy practices to mitigate this risk. First, use cheap, single-ply paper towels. This prevents the radicle from growing between the plies. Second, place only one seed on each paper towel. This allows you to pick up the whole paper towel and avoid touching the sprout when you transplant to media. Finally, don’t keep the seeds in paper towels for too long. Once the root has grown to about 0.5in or 1.25cm, it is time to transplant it to media.
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.
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.
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
- Absorbent paper towels (kitchen)
- Two plates or plastic, opaque Tupperware with a lid.
- Sprayer (optional.
- 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
- 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.
- 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.
- Wet another 6 – 8 paper towels, squeeze to remove excess water and place them on top of your seeds.
- 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.
- 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.
- 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.
- 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.