How to Germinate Weed Seeds – Tips and Methods
Germinating cannabis seeds isn’t a complicated process, although it does require a few specific parameters in order to happen successfully. If you’re reading up on how to germinate weed seeds, you’re in the right place; it’s a relatively easy process, you just need to have some patience on hand. The first thing to keep in mind is that your seeds are going to need water, heat and air in order to germinate.
How to Germinate Weed Seeds – Basic Parameters
Moisture is one of the three elements required to successfully germinate cannabis seeds; it essentially helps the seeds to expand and therefore break their shell. Over-watering at this stage can be fatal for your seeds, although harder-shelled and older seeds can take longer to soak through, so some patience is required.
This can be the hardest thing to work with, because temperatures that are either too cold or too hot will mess with your seeds and they won’t germinate. Springtime temperatures are generally what you should be aiming for – seeds can still germinate in colder temperatures, although they can take longer.
How to Germinate Weed Seeds – Germination Methods
There are many different germination methods that growers tend to use, all of which involve water and heat, although they’re not all as effective as others. Some people prefer germinating by planting straight in the ground, using starter cubes or by letting them soak overnight, although our preferred and recommended method is the paper towel method using either plates or an opaque kitchen container. We’re going to give you a brief rundown of the other methods, alongside their pros and cons.
This method is more reliable than others, and they make germinating quite easy. All you have to do is place your seed carefully in your seed plug and follow the instructions when watering; different brands and models have different watering instructions.
Some cubes are made out of peat and soil, and you can move them straight into your flowerpot once they’ve popped. However, hydroponic growers can use rockwool cubes which can hold quite a lot of moisture.
One of the downsides to using starter cubes is that they’re not very handy if you only want to germinate one or two seeds, because they’re usually sold in packs of 50 or more, and once they’ve been opened most cubes tend to dry out within a couple of weeks. Another downside to Rockwool specific cubes is that they’re bad for the environment, can be bad for your health when inhaled, and they’re not the best method for new growers.
Other growers prefer to get rid of the middle man and plant their seed straight into their first flowerpot – it’s essentially how it would be done in nature, so why not follow the natural order? One of the pros when it comes to planting straight in your growing medium is that you don’t have to stress out your little seedling when transplanting, although it can be a bit harder to get the humidity right and you need to bury it just the right amount so that it can sprout.
We highly advise against using this method, as it’s incredibly easy to accidentally drown your seeds. This method involves soaking your seeds in a glass of lukewarm water – it can be any type of cup, although people usually use a normal glass. This method can be effective for much older seeds or for seeds that have abnormally thick shells.
There are a few myths surrounding germinating in water overnight – some people say that if your seeds sink, they won’t germinate, however the truth is that most seeds start off by floating and then as they soak, they sink to the bottom of the glass. This has nothing to do with germination indication.
How to Germinate Weed Seeds – Paper Towel Method
This method is the method we recommend all readers and customers use, as it’s the one that has proven to give us the highest germination rate. We’re going to give an in-depth step by step guide on how to use this method. Keep in mind that you can skip the rooting hormone part if you prefer all natural results, although X-Seed does provide impressive results to start with.
Material Needed to Successfully Germinate seeds
- Kitchen paper
- Opaque plastic Tupperware or two plates
- Viable cannabis seeds
We’re going to go through the X-Seed method – if you want to skip this, you can simply skip the steps involving X-Seed and place your seeds straight into your paper towel as stated in step 4. Before you start, make sure you have everything you need at hand, so that you don’t have to waste any time looking for stuff. Find the best strains at our Cannabis seeds – Buy Marijuana Seeds section.
Step 1: Soak the seeds
Submerge your seeds in your B.A.C. X-Seed liquid for an hour. Give it a stir every now and then so that the seeds are thoroughly soaked.
Step 2: Germination
While your seeds are soaking, you’ll need to prepare your paper towel and plates (or opaque Tupperware). Make a makeshift “bed” on the bottom plate with damp kitchen paper, but make sure it isn’t soaking. We tend to use 3 layers of kitchen paper; wet the paper and let it dry without wrinkling it, hanging it out kind of like a t-shirt so that all of the excess water can easily drain out. No need to worry about drying it, as you want the kitchen paper to be damp.
Step 3: Separation
After your seeds have been in the B.A.C. X-Seed liquid for an hour, by using a spoon you can carefully extract the seeds from the liquid and spread them evenly across the bottom of your plate or container. An even spread is important, so as the roots of each seed do not get tangled – about an inch apart is good.
Step 4: Cover the seeds
Once you have all of your seeds nicely placed on your plate or in your container, cover the seeds with another layer of damp kitchen paper, similar to the first layer that you put on the bottom. At this point, your seeds should be completely covered.
Step 5: Take care
Once you’ve finished covering your seeds with paper towel, cover them with another plate or put the lid on your container; if doing this in a container, the paper shouldn’t dry out as fast. A mistake made by many growers is that they add too much water to their paper towels if they’ve dried up, but by using a spray bottle you can moisten it some more without overdoing it. If your container is transparent, all you have to do is line the inside so that absolutely no light can get in.
Step 6: Temperature adjustments
Once you’ve isolated your seeds from light, you should leave it somewhere with a nice, neutral temperature. During winter it’s often harder to find a good spot, so you should try and find a heat source that isn’t excessive. You can use a computer modem, or even a softly powered electric blanket. Items like play-stations can get too hot and could end up cooking your seeds, so take care where you put them.
Step 7: After care
Once your seeds open up, they’ll shoot out a small, white root. This means you need to be extremely careful when handling them. Don’t leave them for long because once they’re open they should be moved to soil.
Step 8: Moving to soil
Now that your seeds have officially germinated. Now you need to move them to the medium in which they will remain for the rest of the growing process. Germinated seeds usually grown in soil, but rockwool for hydroponics is also a good option growing. Or even a coco jiffy if you want to cultivate in coco coir. In this article we’ll be dealing with the most common method: planting seeds in soil.
How to Germinate Weed Seeds
Start by filling a small pot with soil, no more than half a liter. Water it before even thinking about planting your seed. Once the soil is damp enough to weigh down the plant pot, use the tip of your finger to create a small 0.5-0.1 cm hole in the middle of the soil, and deposit the seed in the hole with the root facing downwards. Then, cover the seed with a little soil so that it’s just under the surface. The last step in this process is to put your plant pot in the sun or under your lamps (wherever you’re planning on growing it). Within a couple of days you should see that first sprout, that will keep on growing right until the end. In some cases, it may even take a matter of hours.
Keep an eye out on our follow up article on soil preparation for growing cannabis.
Cannabis seeds 101: How to grow marijuana from seed
Cannabis is grown from one of two sources: a seed or a clone. Seeds carry genetic information from two parent plants and can express many different combinations of traits: some from the mother, some from the father, and some traits from both.
In commercial cannabis production, generally, growers will plant many seeds of one strain and choose the best plant. They will then take clones from that individual plant, which allows for consistent genetics for mass production.
If cannabis is legal in your state, you can buy seeds or clones from a local dispensary, or online through various seed banks.
Cannabis seeds vs. clones
For the typical homegrower, it may be easier to obtain cannabis seeds rather than clones. Growing from seed can produce a stronger plant with more solid genetics.
Plants grown from seed can be more hearty as young plants when compared to clones, mainly because seeds have a strong taproot. You can plant seeds directly into an outdoor garden in early spring, even in cool, wet climates.
If growing outside, some growers prefer to germinate seeds inside because they are delicate in the beginning stages of growth. Indoors, you can give weed seedlings supplemental light to help them along, and then transplant them outside when big enough.
Most seeds that you will buy are regular seeds as described above, but here are a couple more types.
How weed seeds work
Cannabis can be either male or female—also called “dioecious”—but only females produce the buds we all know and love. For reproduction, males have pollen sacs and pollinate females, causing female flowers to produce seeds.
Once cannabis seeds are mature, the female plant begins to die, and seeds are either dropped to the ground where they grow into new cannabis plants next spring, or the seeds are harvested for processing into seed oil or food products, or stored so they can be sown in the ground later and become the next generation of plants.
To get the buds found in medical and recreational stores, female cannabis plants are grown in an environment without males—or the males are removed from the area before they release pollen—so the females don’t create seeds. Females can then focus their energies on producing buds and not seeds—this high-potency marijuana is traditionally known as “sinsemilla,” meaning “seedless.”
Some varieties of cannabis can produce male parts alongside female flowers on the same plant, especially if exposed to environmental stressors. These plants are known as hermaphrodites, and sometimes they can self-pollinate to create seeds.
Pros and cons of using cannabis seeds
Check out Johanna’s full video series on how to grow weed on Leafly’s YouTube .
If buying from a reputable breeder or seed bank, growing from seed is the best way to ensure your plants will have solid genetics and start clean, meaning they won’t come with diseases or pests.
Also, buying from a reputable breeder or seed bank will give you a sense of what a particular strain will look and smell like, how it will grow, and how much it will yield at harvest.
The main drawback to growing from seed is there is no guarantee as to what you’ll end up with—if you buy a regular pack of cannabis seeds, it will be a mix of males and females. You’ll need to sex them out (more below) to identify the males and get rid of them, because you don’t want your females producing seeds.
Sexing marijuana plants can be a time-consuming process, and if you don’t catch males, there is a risk that even one males can pollinate your entire crop, causing all of your female weed plants to produce seeds.
One way to avoid sexing plants is to buy feminized seeds (more below), which ensures every seed you plant will be a bud-producing female.
You can also minimize headaches and avoid the hassle of seed germination and sexing plants by starting with clones.
How weed clones work
Aside from producing cannabis through seeds, or sexual reproduction, you can also reproduce the plant through cloning, or asexual reproduction. A clone is a cutting that is genetically identical to the plant it was taken from—that plant is known as the “mother.”
Pros and cons of using cannabis clones
Through cloning, you can create a new harvest with exact replicas of your favorite plant. Because genetics are identical, a clone will give you a plant with the same characteristics as the mother, such as flavor, cannabinoid profile, yield, grow time, etc. So if you come across a specific strain or phenotype you really like, you might want to clone it to reproduce more buds that have the same effects and characteristics.
With cloning, you don’t have to get new seeds every time you want to grow another plant—you just take a cutting of the old plant—and you don’t have to germinate seeds or sex them out and get rid of the males.
One drawback of clones is they need to be taken during the vegetative stage of a plant—flower is too late—so if you have a small setup with only one light, it can be hard to keep clones alive while flowering other plants, because the two need different amounts of light.
Another drawback to clones is they can take on negative traits from the mother plant as well. If the mother has a disease, attracts pests, or grows weak branches, its clones will probably have the same issues.
Additionally, every long-time grower will tell you that clones degrade over time.
What are feminized cannabis seeds?
Feminized cannabis seeds will produce only female plants for getting buds, so there is no need to remove males or worry about female plants getting pollinated. Feminized seeds are produced by causing the monoecious condition in a female cannabis plant—the resulting seeds are nearly identical to the self-pollinated female parent, as only one set of genes is present.
This is sometimes referred to as “cloning by seed” and will not produce any male plants. This is achieved through several methods:
- By spraying the plant with a solution of colloidal silver, a liquid containing tiny particles of silver
- Through a method known as rodelization, in which a female plant pushed past maturity can pollinate another female
- Spraying seeds with gibberellic acid, a hormone that triggers germination (this is much less common)
Most experienced or commercial growers will not use feminized seeds because they only contain one set of genes, and these should never be used for breeding purposes. However, a lot of beginning growers start with feminized seeds because they eliminate the worry of having to deal with male plants.
Top feminized cannabis strain families
A lot of classic weed strains that have been around for a while come in feminized form. Some popular fem seeds are:
- OG Kush
- GSC (Cookies)
What are autoflowering cannabis seeds?
Autoflowering seeds are also popular with beginning growers. They are easy to grow because you don’t have to worry about light cycles and how much light a plant receives.
Most cannabis plants begin flowering when the amount of light they receive on a daily basis reduces. Outdoors, this happens when the sun starts setting earlier in the day as the season turns from summer to autumn. Indoor growers can control when a plant flowers by reducing the daily amount of light plants receive from 18 hours to 12 hours.
However, a type of cannabis called Cannabis ruderalis, which developed in extreme northern conditions without much sunlight, will begin flowering once the plant reaches a certain age—they automatically start flowering regardless of the amount of light they receive, hence the name “autoflower.”
Pros and cons of growing autoflower
Because they grow and flower quicker, growers can fit in multiple autoflower cannabis harvests into the span of one regular harvest.
Autoflowers can be started in early spring and will flower during the longest days of summer, taking advantage of high quality light to get bigger yields. Or, if you get a late start in the growing season, you can start autoflowers in May or June and harvest in the fall.
Also, autoflower plants are small—perfect for closet grows or any small grow, or growing outdoors where you don’t want your neighbors to see what you’re up to.
A couple big drawbacks, though: Autoflower strains are known for being less potent. Also, because they are small in stature, they usually don’t produce big yields.
However, potency in autoflowering varieties has increased significantly since their initial introduction, with some breeders crossbreeding the low-THC ruderalis with other more potent varieties.
Tips for growing autoflower marijuana seeds
Autoflowering strains require some preparation, as they will grow quickly and start to flower whether or not you’re ready for them.
Many marijuana growers start autoflowers early in the season, and at a different time than a regular crop, so keep the season and climate in mind when growing and harvesting—your plants still need warmth to grow, and rain can give them bud rot. Consider growing in a greenhouse to protect them.
Because training happens during vegetative growth, for autoflowering plants, this period could be as short as a few weeks, which means time is limited. Try topping your autoflowers after they have three nodes, and stop once they begin to flower. You will want to prune them lightly.
Go easy on nutrients
Autoflowers don’t need lots of nutrients because they’re small and don’t spend much time in the vegetative cycle. They won’t need as much veg nutrients—such as nitrogen—but will need more bloom nutrients.
What are high-CBD cannabis seeds?
CBD, or cannabidiol, is one of the chemical components—known collectively as cannabinoids—found in the cannabis plant. Over the years, humans have selected plants for high-THC content, making cannabis with high levels of CBD rare. The genetic pathways through which THC is synthesized by the plant are different than those for CBD production.
Cannabis used for hemp production has been selected for other traits, including a low THC content, so as to comply with the 2018 Farm Bill. Consequently, many varieties of hemp produce significant quantities of CBD.
As interest in CBD as a medicine has grown, many breeders have crossed high-CBD hemp with cannabis. These strains have little or no THC, 1:1 ratios of THC and CBD, or some have a high-THC content along with significant amounts of CBD (3% or more).
Seeds for these varieties are now widely available online and through dispensaries. It should be noted, however, that any plant grown from these seeds is not guaranteed to produce high levels of CBD, as it takes many years to create a seed line that produces consistent results. A grower looking to produce cannabis with a certain THC to CBD ratio will need to grow from a tested and proven clone or seed.
How to germinate marijuana seeds
Germination is the process in which a seed sprouts and begins to grow into a new plant. Also referred to as “popping,” germination is the very first step in starting your weed grow.
Marijuana seeds can be acquired from an array of sources and can vary in quality. For more info on how to buy marijuana seeds, check out our Guide to buying cannabis seeds.
Cannabis seeds require three things to germinate: water, heat, and air. There are many methods to germinate seeds, but for the most common and simplest method, you will need:
- Two clean plates
- Four paper towels
- Distilled water
Take four sheets of paper towels and soak them with distilled water. The towels should be soaked but shouldn’t have excess water running off.
Take two of the paper towels and place them on a plate. Then, place the marijuana seeds at least an inch apart from each other and cover them with the remaining two water-soaked paper towels.
To create a dark, protected space, take another plate and flip it over to cover the seeds, like a dome.
Make sure the area the seeds are in is warm, somewhere between 70-85°F.
After completing these steps, it’s time to wait. Check the paper towels once a day to make sure they’re still saturated, and if they are losing moisture, apply more water to keep the seeds happy.
Some seeds germinate very rapidly while others can take a while, but generally, seeds should germinate in 3-10 days. If it’s been two weeks and a seed hasn’t sprouted, it’s probably a dud and won’t sprout.
A seed has germinated once the seed splits and a single sprout appears. The sprout is the taproot, which will become the main stem of the plant, and seeing it is a sign of successful germination.
It’s important to keep the delicate seed sterile, so don’t touch the seed or taproot as it begins to split.
Transplanting germinated cannabis seeds
Once you see the taproot, it’s time to transfer your germinated seed into its growing medium, such as soil.
- Fill a 4-inch or one-gallon pot with loose, airy potting soil
- Water the soil before you put the seed in; it should be wet but not drenched
- Poke a hole in the soil with a pen or pencil—the rule of thumb is: make the hole twice as deep as the seed is wide
- Using a pair of tweezers, gently place the seed in the hole with the taproot facing down
- Lightly cover it with soil
Keep a close eye on the temperature and moisture level of the soil to keep the seed happy. It’s very delicate at this stage. Use a spray bottle to water it—over-watering can suffocate and kill the delicate sprout.
Within a week or so you should see a seedling begin to grow from the soil.
Germinating cannabis seeds doesn’t always go as planned. Some seeds will be duds. Others will be slow and take longer to sprout. But some will pop quickly and grow rapidly.
This is the beauty of seeds—often, you can tell which plants or genetics will thrive right from the get-go. This will help you determine which plants you want to take cuttings from for clones or for breeding if you want to create a seed bank of your own.
How to sex a pot plant
Check out Johanna’s full video series on how to grow weed on Leafly’s YouTube .
As we’ve mentioned, cannabis is a dioecious plant, meaning male and female reproductive organs appear on different plants.
Because only female cannabis plants produce buds and you want them to focus all their energy on producing buds and not seeds, it’s important to identify and get rid of male weed plants so they don’t pollinate females. If females are pollinated, it will give you buds filled with seeds, making your weed harsh and unpleasant.
Cultivating males is important for breeders trying to cross new strains and genetics, but most people growing for buds will want to remove the males.
As mentioned above, you can skip the processing of sexing weed plants by growing with feminized seeds or clones.
If growing male and female cannabis seeds, they’ll start to show their sex organs, or “pre-flowers,” after 8-10 weeks from germination.
Cannabis plant sex organs appear on nodes, the points where branches grow off from the main stalk.
Males will have round balls—these will develop into pollen sacs, which will release pollen into the air when mature.
Females will have a round structure with long hairs—these hairs will develop into pistils, which will catch pollen in the air.
Pre-flowers can initially be extremely small and hard to identify with the naked eye, but you can use a magnifying glass to get a better look.
Can I grow a seed I found in a bag of weed?
Finding a cannabis seed in your stash is not ideal, but we’ve all been there before. Although much less common than it once was, it still happens. Sometimes you’ll notice one when grinding down some flower, or you’ll see one pop, spark, and crackle from the heat of a lit bowl.
These are referred to as “bagseeds” and whether or not you can grow one will depend on where it came from.
Is a bagseed good or bad?
Seeds found in finished cannabis buds can develop for a number of reasons. For example, a male plant may have accidentally pollinated a flowering female during the growing process. But more commonly, they’re a sign of stress and can be attributed to high temperatures during the final stages of flowering or an exaggerated spike in climate or environment.
Seeds can also form in plants with genetic disorders or instability, like hermaphrodites—plants that develop both male and female reproductive parts. Generally, stress and genetic disorders are viewed as bad, so temper expectations with any plant you start from a bagseed.
But sometimes you get lucky and find a mature seed in some really nice herb. Strains like the legendary Chemdog wouldn’t be possible without adventurous smokers planting and proliferating the seeds they found in a bag of kind bud.
So don’t discount bud because it has a seed or two in it. While not ideal, it could be the origins of the next great weed strain.
Ask yourself a few questions to decide if it’s worth the time and energy to grow the seed.
Was the seed found in good weed?
If you don’t like the flavor, effects, or even the look of the bud, then it’s probably not worth growing.
Are you ready to grow?
Growing marijuana takes a certain level of commitment: time, energy, and financial resources, so be sure you can commit to the whole process.
Is the seed viable?
For a seed to be viable, it must be mature enough to have a completely formed genetic blueprint, and it must be strong enough to germinate and pop through its hard casing and sprout its crucial taproot.
There are a few indicators that will give you a sense of whether the seed is worth germinating.
- Tiger stripes—dark stripes on the seed which resemble veins on a leaf are generally good
- Solid shell—a seed should be able to withstand a little pressure when pinched between your fingers; if it crumbles or cracks, it’s no good
Immature seeds tend to be light in color and have a soft outer shell.
In some cases, even if a seed isn’t completely mature, there’s still a chance it could be viable. But often these are extremely weak, take long to develop, and express other unfavorable characteristics. Growers usually discard weak plants to free up space.
You might also find a mature seed that has been physically damaged through poor handling, like rough trimming. In those cases, it probably isn’t worth the effort to try and germinate the seed.
But if the seed you found looks decent, you might as well germinate it and see what sprouts.
Time to germinate
Viable or not, there’s only one sure way to find out if a bagseed will grow. If you’re simply curious to learn and not as concerned with the overall outcome, you can plant a couple of bagseeds outside and see what happens.
If you’re ready for a more serious approach, make sure you have the space for a proper garden and pop the seeds to see what fruit they bear.
Even if your seed sprouts fast and grows vigorously, it still has roughly a 50/50 chance of being female and producing buds, instead of turning out to be a male.
Remember, once a seed germinates, the real work begins. Sexing, selecting, vegetative growth, flowering, and the eventual harvest all lie ahead.
How to buy cannabis seeds
Cannabis seeds can be found on numerous online seed banks, but note that it is illegal to bring seeds into the US and Customs will seize any cannabis seeds that they find in packages or on a person. In legal and medical states, you may purchase seeds at a dispensary.
How to Germinate Cannabis Seeds
This article was co-authored by Lauren Kurtz. Lauren Kurtz is a Naturalist and Horticultural Specialist. Lauren has worked for Aurora, Colorado managing the Water-Wise Garden at Aurora Municipal Center for the Water Conservation Department. She earned a BA in Environmental and Sustainability Studies from Western Michigan University in 2014.
There are 10 references cited in this article, which can be found at the bottom of the page.
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Cannabis sativa sp. is commonly known as marijuana and has been grown throughout the world for thousands of years. Cannabis seeds germinate in 3 to 7 days, though some varieties may take 10 to 15 days. While germination is a natural process, factors such as light, humidity/moisture, and temperature must be controlled for cannabis seeds to sprout.