How to germinate cannabis seeds

Germination begins the life of your plant, so it is essential to understand precisely how to do it. There are many methods for germinating marijuana seeds – some more successful than others.

This guide will discuss the many ways to germinate your seeds as well as some strategies for ensuring you get the best results possible. But if even the right methods fail I stand by my seeds and replace non-germinated seeds for free.

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It starts with the cannabis seed

Like all plants, marijuana starts as a seed. What looks like a pebble is actually an entire plant conveniently stored with a few days supplies of food to support itself. During germination, this food is converted into sugars that the plant uses to break through its shell and form its roots. From that point forward, the young seedling depends on its environment to provide the nutrients it will need to survive.

Germination brings a seed out of its slumber and triggers the growth process. A seed will begin germinating once it receives enough moisture. At that point, it will increase in size and break open its shell. A germ opening forms and a root will emerge, which will help the plant absorb nutrients from the earth.

germination helps sprout seeds
Sprouted marijuana seeds

Nature and gravity ensure that the root grows downwards and the stem upward, creating a young seedling that can survive off light and earth.

Since all marijuana grows from a cannabis seed, many people want to know how to identify a healthy seed. Honestly, it is difficult to tell if a plant will be healthy based on its seed alone. There are, however some tell-tell signs.

Planning your first grow? Check out my easy beginner seeds and grab an all-in-one Pot for Pot solution

Generally speaking, a pale-green, white, or very dark marijuana seed may have trouble germinating well. But this does not always reflect the outcome of the plant and is always worth trying.

If you are unable to use all of your seeds, store them in a cool, dark and dry place until you can. A refrigerator is ideal.

Planning for marijuana seed germination

Seeds are designed to germinate, but they are more likely to do so if given the ideal environment. There are many methods of germination, but they will all require:

  • Moisture to help the seed expand and break through its shell
  • Minimal interference so that delicate structures aren’t accidentally broken
  • Temperatures that mimic springtime (between 20°-22° Celsius or 68°-72° Fahrenheit)

If you remember these three things, your germination attempts are more likely to be successful.

Planning for Germination
A Seedling’s first leaves

It should go without saying that successful germination is important. Your seed is the foundation for your plants – which is why many successful growers choose to start with high-quality seeds.

You can also improve your germination attempts (and possibly speed up the process) by soaking your seeds in 1% hydrogen peroxide or a compost tea solution for 12 hours before using them. This process will kill any infectious agents.

3 Simple ways to germinate your cannabis seeds

The best germination method is the one that works for you, and if you are like me, you’re going to want something simple and natural.

My favorite way to germinate seeds is a 24-water soak followed by soil germination, but something else may work better for you. Here are three of the easiest ways to germinate seeds.

Germinate weed seeds directly in soil

Planting your seeds in the soil that you intend to grow in is the most common and often, most successful method of germinating marijuana seeds.

This method is perfect for ensuring young seeds have minimal interference since the fragile root is protected by the soil. It’s also the most natural way for marijuana plants to grow.

A freshly popped seed in soil starting to germinate
A freshly popped seed in soil

How to plant marijuana seeds directly in soil

The first step in learning how to plant marijuana seeds directly in soil is to first make sure you use the right type. Use mildly fertilized potting soil or a seed starter. It should have a pH of approximately 6.

This type of soil will have spores and minerals that help young marijuana plants thrive. Do not add nutrients – potting soil has enough nutrients for at least the first two weeks of the plant’s life. If you add any more nutrients, you risk killing your seedlings due to a nutrient overdose. Place your soil in a small pot.

In my free Grow Bible you will find even more tips for sprouting seeds and how to germinate weed seeds

Steps to germinating cannabis seeds

To prepare the soil for your seed, push your finger into it to create a small hole that is up to 1.5cm (0.6 inches) deep.

You can also use a pen or pencil.

  1. Place one seed into the prepared hole and cover it with soil. If you’ve already germinated, the seed will have a root – place the root facing downward (more on that later).
  2. After you’ve covered your seed with loose soil, do not mess with it.
  3. That includes pushing it down further – this will happen naturally as you water it.
  4. Use a plant sprayer to moisten the soil and place the pots under a fluorescent lamp.
  5. Don’t use a windowsill, because the temperature is not stable enough for germination.
  6. The temperature of the soil should be 22° Celsius or 72° Fahrenheit which is easy to achieve with lighting.
  7. Keep monitoring your soil or grow medium to make sure it stays moist.
  8. Within a week (or as little as 4 days) you should start seeing stems emerge from the soil. You now have a seedling!
  9. Once your plants are 2 to 4 inches tall (5 to 10 centimeters), transplant your cannabis plants into a larger pot with the stems further in the ground. Your plant will now have many roots that will support it for the rest of its life.

Germination marijuana seeds timelapse

Germinate seeds in water

As I mentioned above, germinating in water is my favorite way to start my seeds. It may seem like a bad idea, as there are more water and light than recommended when using this method, but it works! I’ve found that it is around 90% effective.

germinating seeds in water
When germinating in water, seeds will sink to the bottom once they’re soaked

The “trick” is not leaving the seeds in water too long. Usually, 24 to 48 hours is enough for the seeds to show their tail, but you can leave them soaking for up to 7 days without too much of a worry.

Weed seed water germination

Water germination is useful because it assures that there is the right amount of moisture to begin germinating. If done for just a short period, it can help crack open the shell, pre-sprouting the plant right before your eyes. 

Water germination shortens the process by making it easier for the plant rather than having to push through the soil.

  • To germinate with water, fill a glass with tap water and allow it to reach room temperature over a few hours.
  • The temperature should be around 18° C or 65° F. Do not add nutrients. Drop 2 to 3 cannabis seeds into the water and watch for any changes.
  • Refill the glass with fresh water every other day while maintaining its temperature.


After about 2 to 4 days the seeds should start to split. You can place your seeds in the soil at any point, but once the roots are 3 to 5 mm (.1 to .2 inches) long, they must be planted.

These are the basic instructions from my store that I share with new growers:

marijuana seeds germination guide
marijuana seeds germination guide

As much as I prefer to germinate my seeds in water, it does have its downside. At some point, you will need to handle your seeds, and this is risky. Germinating seeds are delicate, and the roots are especially fragile. If you harm them in any way, your plant might not develop well.

Germination marijuana seed
Germination process marijuana seed

Be very careful when placing your sprouted seed into the soil, and if possible place the root facing down.

Germinate with cotton pads or paper towels

Another easy way of germinating your cannabis seeds is to use cotton pads or paper towels. This is called the paper towel method. This is a common way of doing it because cotton pads or paper towels can keep the seeds moist and protected.

While cotton pads (or balls) or the best for this method, cheap, non-porous paper towels will work as well.

germinating pot seeds In between two cotton pads
Seeds sprouted between cotton pads showing their first tail

Just make sure they are plain single-ply paper towels – the cloth-like ones may cause your roots to grow into the towel.

  1. To germinate using cotton pads, place a few seeds between two cotton pads and moisten with a plant sprayer.
  2. When using a paper towel method, place the seeds in between two paper towels and store the towel-cushioned seeds in between two plates, under an upside-down bowl or in a plastic bag.
  3. Keep the temperature around 22° Celsius, or 72° Fahrenheit, and (once again) do not place the seeds on a windowsill.
  4. In about 2 to 5 days, the seeds will start to split open, and a tiny root should appear.
  5. Place them in the soil when they are 3-5 mm or 0.1- 0.2 inches long.

Like the water method, germinating this way has its risk. If you are not careful, you can damage fragile roots while transporting them to the soil. You can also tangle the root in the wet paper towel if you are not extremely careful.

Use tweezers to move delicate sprouts, and don’t allow the root to grow too long before moving it into the soil.

Other germination methods

Water, soil, and cotton pads or paper towels are the easiest ways to germinate your seeds, but they aren’t the only ways. You can also use starter cubes or plugs for germinating cannabis seeds. Simply drop the seed in, add water, and wait for it to germinate.

They aren’t always as successful, but they eliminate the risk of damaging your root when transporting a young sprout to its final growing home. Below are two types of starter materials that can safely germinate your seeds.

Germinating cannabis seeds in rockwool

Rockwool provides the perfect environment for germinating seeds. It is mineral wool that is made from volcanic rock and other materials (such as basalt and limestone). Rockwool is man-made by melting its ingredients into molten lava that is quickly spun into threads. These threads are then compacted, cured, and cut.

Rockwool need to be amended slightly for marijuana plants. First of all, you will need to add some fertilizer before you use it to start seeds. The TDS should be around 600ppm. You’ll also need to lower the pH since Rockwool has a pH of 7.0, which is too high for germination.

To lower the pH, soak Rockwool plugs in water for at least a day. Since water has a pH of 5.5, this will bring down the pH.

Rockwool Germination
A sprouting seed in rockwool

It should also be noted that there are some serious drawbacks to using Rockwool. Because it does not occur naturally, it’s not the best for the environment.

It’s also not the greatest for your health; wear gloves and cover your mouth and eyes when handling this stuff. Because of the extra steps involved (such as adjusting the nutrients and pH) and handling issues, this method is not recommended for beginners, although it is not terribly difficult to do.

You’ll need to purchase and TDS meters for the most successful germination, but outside of that, the material is very affordable and easy to find. Because it does not require soil, this method is ideal for those who plan to grow hydroponically.

Germinating seeds in peat pellets

Peat pellets are another way to germinate seeds without the risk of damaging young roots. Peat pellets are compressed peat, which is made of partially decomposed vegetable matter and is simply yummy for young cannabis plants.

The pellet enlarges when you add water to it, forming a container of nutrient-dense soil alternative around germinating seeds. Unlike Rockwool, peat is already optimized for cannabis germination.

It has a pH of 5.5 and a TDS of 625, so you don’t have to worry about making any adjustments. The only preparation required is soaking the pellets in warm water.

germinate cannabis seeds using Peat Pellets
A sprouted seed in a peat pellet

Once the roots become visible, (by popping out of the peat), simply move the entire pellet into the soil, rock wool, or coco coir, where it will continue growing. This type of germination is not recommended for hydroponic setups.

Peat pellets have a good germination rate for when you germinate cannabis seeds, are easy to use, and are suitable for beginners. They are also ideal for cloning.

Also read How to make marijuana clones

I recommend the Jiffy brand of peat pellets which can be purchased on Amazon.

Germination environment

In addition to the material used to germinate your cannabis seeds, the grow environment you provide will play a huge role as well. Your seeds will need the correct temperature and levels of moisture to sprout into a strong, healthy plant.

“Weak plants are the result of weak seeds and poor growing conditions.”

Jorge Cervantes

Below are some tips for creating the perfect germination environment.

How to water sprouting seeds

Watering is essential throughout the cannabis life cycle, and germination is no exception. Not enough water and your seeds do not germinate, too much and that root doesn’t survive. Excess water keeps oxygen from the roots and can attract mold, which is why you have to be very careful not to overdo it.

When germinating weed seeds indoors using soil or another growing medium it is relatively easy to monitor the water levels. You should water your seed until you see water dripping out from below (and not more). Even though the seedling cannot absorb that much water, it will evaporate quite quickly, so you need to make sure there is always enough around. If you water it until it reaches this point, it should supply enough moisture for a few days.

Lighting and temperature

Like water, lighting is essential to a cannabis plant. In a mature plant, light enables the plant to form sugars from carbon dioxide and water.

The plant then uses those sugars to power its growth – something we humans call it photosynthesis. For a cannabis seed, lighting is important as well because it provides heat, which a seed needs to push open its shell and send its root into the earth.

You can find out what the best light cycle for growing weed by reading our guide.

The best way to give your seeds the temperature it needs is with fluorescent lights. (T5 high output with a color temperature of 6500K). Fluorescent lights are ideal because they do not use too much power, and they don’t give off too much heat.

You can place them as close to a young cannabis plant as you need, and although your seed doesn’t need it at this point, it will as soon as those first leaves start peeking out from the top of the soil. Incandescent bulbs can also be used because they are great at generating heat. You can’t use them as grow lights, but for germination, they work just fine.

You can also use a seedling heating pad (available at most gardening stores). These heat the seeds from the bottom instead of the top. They will not be enough once your plant has started growing, however.

Keep the temperature of the soil around 72 degrees.

Seeds germinate best in warm, humid temperatures, similar to springtime. To create a humid environment, wrap plastic wrap around your pot, creating a biodome for your plants. Just remember to remove the plastic wrap the minute you see any sprouts emerge from the soil.

If the soil, or water, or whatever you are growing in is hotter than 72 degrees Fahrenheit, move the lamp further away from the plant. Dry air won’t kill seedlings, but if you can reduce it, even better.

Where to germinate cannabis seeds

When you’re planning your outdoor grow and you received your seeds, it’s best to germinate them indoors. This is because indoors it is much easier to maintain the correct temperature, water levels, and light exposure. Even if you plan to grow your cannabis plants outdoors, you do not want to try starting them outside (unless you absolutely need to).

Outdoors you must worry about rain, clouds, and plenty of other things that could keep your seeds from sprouting. You’ll also have to wait until the final frost has passed, meaning your growing season may be delayed compared to if you had started the seeds inside.

Starting indoors gives you a head start and your plants a better chance at survival.

outdoor germination
Outdoor germination

If you still plan to germinate cannabis seeds outdoors, choose a location that will support the plant its entire life. You will not be moving the plant so choose wisely.

  • Plant seeds when corn is typically planted in your area.
  • Dig 6x6x6 holes at least three feet apart and fill them with potting soil.
  • This will give the seeds enough nutrients to start.
  • Then, dig a small, quarter-inch deep hole into the potting soil and drop the seed in.
  • Soak that soil with water, and water it again in a few days if the weather is warm enough.
  • You can use row covers to protect your seeds and keep the area warm but be careful to not leave them on too long – young plants will need the light once they break through the soil.

There is, of course, a benefit to starting your seeds outdoors if you plan to grow outdoors. Your plant will have more time to adjust to its environment and will be less likely to suffer from shock when moved outdoors.

Cannabis seed sprouting

So it might be worth it if you know what you are doing.

Just remember to leave plenty of space for your cannabis plants (those little cannabis seeds can grow quite large), know the weather patterns in your environment, keep your eye out for animals that may eat your seeds, and use potting soil to provide the right amount of nutrients.

Planting your germinated seeds

Once your seeds have sprouted, they should be planted. If you’ve used a cannabis germination method that requires you to move your sprouts, do so carefully, as the taproot is very fragile.

You do not want to touch it. If you touch it or break it, it may survive, but it will definitely stunt your plant’s growth.

planting germinated cannabis seeds

When planting, drop the white root downward. It should be placed about half an inch to an inch in the growing medium (knuckle deep). The top of the cannabis seed should sit just below the surface. Cover lightly and allow about a week (10 days maximum) for the seedling to break through the soil. It may emerge the same day – but if it hasn’t peeked through by 10 days, it likely did not survive.

If your seed is accidentally planted upside down, do not worry. Nature has a way of working itself out. As long as there is enough room for the roots to grow down eventually, they will. Give it some time and let it do its thing!

Germination doesn’t have to be hard. Are you ready to start growing?

It all starts with the right seeds. Our high-quality seeds will improve your germination efforts and even come with a guarantee.

FAQ about germinating cannabis seeds

Is it better to germinate seeds before planting them?

Yes. This is true with most plants.

Do seeds germinate better in the dark?

Yes. Cannabis seeds will germinate better in the dark.

Should cannabis seeds be covered to germinate?

Yes. This will trap the moisture and prevent it escaping into the atmosphere.


If you’re looking to buy seeds be sure to check my strain selection. I always get the best genetics and if by bad luck, your seeds don’t germinate I stand by my word and replace the seeds for free!

Germination starts with finding the right seeds. Get high-quality marijuana seeds from my seed shop and begin your grow journey now!

Find detailed information about ordering in our support section.

Happy Growing!

Robert

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Robert Bergman

Founder

Robert Bergman is an Amsterdam-based marijuana grow expert who has years of experience from small grows to massive operations ... See profile