How To Germinate Weed Seeds (Fool-Proof Method)
Whether it’s your time to step into cannabis cultivation, or you’re just curious about the process, here we are, ready to learn how to germinate weed seeds.
Also referred to as “popping seeds” or “popping beans,” germinating seeds is the first step in growing cannabis from seed (growing from clones is a bit of a different story). This article contains everything you need to know before you germinate your seeds, and the best method to go about it.
(Note: This guide is for educational purposes only and not intended to be followed if it would place you at odds with local and/or federal law.)
What Is Germination?
Germination is the process by which a new plant grows from a seed. Every plant seed, not just cannabis, contains a tiny, ready-to-grow dormant plant, curled up around a tightly packed store of nutrients. When you plant seeds of any kind, these seeds germinate as the first step of their life.
When plants produce seeds, they send off these potential offspring into the world, ready to spring into action when the conditions are right: usually a dark, warm, moist place. The darkness paired with moisture are key indicators to the seed that it’s time to wake up and start growing a plant from the soil (or whatever other growing medium) it’s in. Essentially, telling the plant it’s spring time, and time to start growing!
When those conditions are met, the plant inside the seed awakens from its dormant state, sends a tap root down into the soil, sends its first stem up towards the air above and the seedling starts to grow b!
Why Do We Germinate Cannabis Seeds?
Germination happens in the wild all the time, since it’s the process by which plants produce offspring via seed. When we’re growing cannabis from seed, we want to control as much of the process as possible to limit any potential issues, starting with germination of our cannabis seeds.
There is another way to grow cannabis, from “clones,” but you need to have a mother plant to begin with! How do you get that mother plant? Often, through your chosen cannabis seed.
For breeders, germination is a crucial step in the pheno-hunting process (phenotype hunting), in which dozens, and sometimes hundreds of cannabis seed are germinated and grown, to the find the proverbial needle in the haystack of the perfect marijuana plant, to then clone from.
For beginner growers, especially those that can’t find themselves cannabis seedlings, purchasing from cannabis seed companies is the only way to get their first plant, so learning to germinate cannabis seeds will be essential for any new grower getting started.
What’s the Best Way to Germinate Cannabis Seeds?
There are a few ways to handle germinating your seeds. This most basic, tried and true method requires just a little bit of household equipment and a few days! Put frankly, cannabis germination is something that is hard to mess up, so you should have “great success” with this method!
What You Need
- Two small side plates
- One or two sheets of paper towels
- Tap water (distilled/filtered, ideally but tap water usually works just fine)
- A warm, safe location you can leave them (70-90°F) that won’t get knocked over
- Cannabis seeds
Step 1: Stack & Soak
Stack your paper towels one on top of the other and fold them into a square. Then, soak the paper towels with your water. You don’t want them sopping wet (dripping) but they should be thoroughly dampened. Hold them up while they drip until they stop dripping altogether. Place them on one of your plates.
Step 2: Lay Out & Label
Unfold one fold of your paper towel, put it on your plate, and lay your cannabis seeds out, evenly spaced. We recommend adding some sort of label if you’re popping seeds of multiple strains, and include the date you’re starting them.
Step 3: Nighty Night!
Fold back the paper towel over the cannabis seeds to cover them, and place the second plate upside down, on top of the first plate, creating a dark, safe space for your seeds to start to come to life!
Step 4: Warm, Watch, Wait
The length of the taproot before transplanting is a bit of a personal preference, but we recommend waiting until there is at least a half inch of root. Carefully pick up the seed and place it in your growing medium – whether that’s soil, rockwool or coco – root facing down. Use tweezers to pick it up if you’re worried about being gentle enough!
If the seed coating didn’t shed from the cotyledons (the first two leaves on a seedling, pronounced “coddle-edens“), try not to remove it. You risk damaging the leaves and stem and the seedling should shed the seed cap on its own.
Make sure your growing medium is properly moist, using a spray bottle if you have one, to keep your watering gentle and seedling safe. Pouring water onto your seedlings can cause them to fall over, so be gentle.
Step 5: Transplant
Place the seeds in a warm location, ideally somewhere between 70°F-90°F, for a few days. Room temperature is fine usually. Too hot and you will dry out and cook the seeds. Too cold, and either it will take too long and the seeds will mold/rot before they sprout, or it won’t stimulate the seeds at all.
You’ll want to check the seeds frequently (daily is ideal) to make sure the paper towel doesn’t dry out. Just add more water if required.
After anywhere between three days and 14 days (yes, there can be that much variation!) you’ll see the tap root emerging from the seed! If you wait even longer, the seed can also shed, exposing pale, green, rounded leaves called the cotyledons. If kept in the dark too long they may appear more yellow than green, but that will go away in time.
Not all seeds will germinate, and you can just discard any duds. Give them enough time to make sure they’re not just late bloomers though!
You also might see tiny white fuzz on the root, but don’t panic – those are likely root hairs, not mold! Mold is very distinctive (when you know what you’re looking for); these roots hairs are still fibrous, and won’t drift away at a breeze or touch.
Step 6: Let There Be Light!
You’ll want to move your new seedlings in their growing medium to a location with a significant source of light, that’s on for anywhere between 18 to 24 hours.
Seedlings that don’t receive enough light will stretch to reach the light making them tall and gangly and risk damage. Seedlings with too much light can be stressed into submission. Generally, a cheap fluorescent light a few inches away is the way to go. A fluorescent grow light is enough light for the seedlings, without producing heat to stress them out. Eventually, you’ll want a more powerful grow light, though!
You’ll now want to consider adding a small, light fan to your grow space at this point as well, blowing very softly, so as not to blow the seedlings over, but just to provide a little resistance, allowing the cannabis seedling to stiffen up.
Now that you’ve got cannabis seedlings, you’re ready to take your growing to the next stage – vegetation – producing a big healthy plant that’s ready to either make clones or take into the flowering stage after a few weeks.
The taproot from your seedlings will shoot down towards the bottom of your grow container, as more roots extend from the taproot and spread throughout the container. Healthy cannabis roots are bright white, and at this stage of the grow it’s important to nurture those roots as best as you can.
Maintaining the proper pH of the soil or growth medium (5.8-6ish) and being careful not to over-water (a classic beginner error) is going to be crucial to maintain strong, healthy roots.
Other Germination Methods
Straight in Soil
Of course, most seeds in nature germinate straight in soil, and this is definitely an option when you germinate cannabis seeds as well, and many purists will recommend you do this.
That being said, in our opinion, the paper towel method is an easier way to maintain a consistently moist environment, suitable for your seeds during such a crucial step. It also allows you to remove any dud seeds before spending more time on them!
Other sites will also recommend you put your paper towel in a plastic sandwich bag. We’d caution against this unless you aren’t going to be able to watch your seeds for an extended period of time. The lack of oxygen and build up of moisture can cause unwanted molds and bacteria to find their way in.
If you’re having trouble keeping the paper towel moist from day to day, use a plastic sandwich bag but don’t close it, to help keep that oxygen flow moving and mold from settling in.
Optional Pro Tips
Pre-Soak & Scrape
Some folks recommend soaking their seeds overnight in a glass of water before beginning germination (and for some, rare and particularly stubborn strains, even scraping the seed coating to thin out the seed making it easier for the seed to germinate) but in general, neither of these techniques is required for the majority of seeds out there.
Some growers will also opt to soak seeds in a diluted solution of hydrogen peroxide to sterilize the exterior of the side prior to germination. Because some seeds are rare – and expensive – growers will do just about anything to improve the rate of their germination attempts and guarantee success.
How to Select Cannabis Seeds
Ready to get your hands on some cannabis seeds and get started? There are a few different types of seeds you may not have been aware of. Aside from picking the strain you want to grow, you’ll want to keep these things in mind as they can profoundly impact your grow.
Mature Seeds vs Immature
Pictured above is a mature seed next to an immature seed. The smaller, green seed can still possibly germinate, but it’s also possible it’s too underdeveloped. If you purchase seeds and they don’t look like the one on the left, you should definitely take it up with your seed bank.
Auto-Flowering Seeds vs Regular Seeds
Auto-flowering cannabis seeds can be purchased from many seed banks and have certain advantages over regular seeds.
Auto-flowering seeds contain the genes from Cannabis ruderalis, a subspecies of cannabis that does not begin its flowering stage of plant growth, based on the amount of light it receives. In other words, an auto-flowering plant will begin to flower on its own, and not depend on the grower changing the light schedule it receives.
Marijuana plants grown from regular seeds will only flower if provided a light cycle of 12 hours on, 12 hours off, or if some other major stressor causes the plant to pre-maturely flower.
What does this mean for you? If you have the ability to vary the light your plants receive, or want to produce a single harvest outdoors, then regular seeds are a good option for you.
Feminized Seeds vs Regular Seeds
Many seed companies also sell feminized cannabis seeds, which many people prefer to purchase for their first time. Regular marijuana seeds produced from a “male” and “female” cannabis plant have a 50-50 chance of being either “male” or “female.” In most cases (unless you are breeding plants) the female plants are the only seedlings you’ll want to keep.
Feminized seeds are produced by applying colloidal silver to a flowering and pollinated cannabis plant. Some growers lament that you increase the risk of cannabis plants developing hermaphroditism in the flowering stage and stay away from them.
Distinguishing between males and females in the garden can take experience, time, energy and resources, so feminized seeds provide a great solution for beginners, in particular.
Germinating your own cannabis seeds at home doesn’t have to be a daunting task, and we hope today’s lesson has given you the seed of inspiration to try sprouting weed seeds on your very own – Local laws allowing, of course. Happy growing!
How To Germinate Old Cannabis Seeds
We can only expect to use the old seeds with the cost of seeds floating above potheads’ reach. However, improper or long-term storage of seeds can cause infertility – and they cannot germinate. However, how do we let those old cannabis seeds come to life again? This guide will help us convert the relics into a sea of green sections of robust cannabis fields!
Sorting Old Cannabis Seeds
The first step in any farming process is to make sure we have the right seeds, and the same goes for weeds. When harvesting autoflowering marijuana seeds, everything is preserved, and nothing is lost. This means that all types of seeds are ripe and immature. How do we distinguish good seeds from bad ones? You are considering the following.
Sorting Seeds By Color And Shape
Whether we obtained the seeds from a seed bank, a store, or a retailer, different cannabis seed strains have different colors. Mature cannabis seeds acquire a dark coat, while immature ones are brighter and usually white. The most visible colors are brown, tan, and sometimes black. In contrast, bright yellows and whites quickly identify immature seeds.
Cannabis seeds are known for their aesthetic properties and shape. Round and symmetrical seeds are best. Larger seeds have a reasonable rate of germination compared to small seeds, which tend to be immature.
Classification Of Seeds By Hardness
Although the seeds have taken some time inside storage containers, ripe weeds seeds’ hardness is not compromised. Hard and tough seeds with a smooth shell guarantee a reasonable degree of germination. Also, pay attention to wavy and cracked seeds. They will lose time and energy and will not germinate after planting.
Ways to Germinate Old Cannabis Seeds
Below we will go through 3 popular methods used to germinate old weeds seeds. Remember that we have to do the part by trying to keep the temperature between 26 ° C – 28 ° because that is where the clones seem to season-best. You must also ensure that the seed is kept in a dark area, as light can slow down the germination process.
Method 1 – Scarification
The first method is scarification. This includes causing injury to the seeds’ outer shell to allow water and air to enter, which is essential for germination. For manual scarification, we will need a container or box lined with sandpaper or any coarse material to scar the seeds’ outer surface. Put the seeds in a container or box and shake. After a while, we will find that the roots become dull, and we can see parts of the sources inside the container. Once we scare the outer shell of the cannabis seeds, we can germinate them as usual.
Method 2 – Carbonated water
The second method involves the use of carbonated water with a pH below 7. This slightly acidic solution absorbs the outer layer of the seeds. Put the seeds in a container full of carbonated water and wait for about two hours. The solution loosens the seed coat and allows it to absorb water, which helps germinate.
Method 3 – Mixture of hydrogen peroxide
Method 3 requires that we use a mixture of hydrogen peroxide to soften the seed’s outer skin. It would be best if we were careful when mixing the peroxide solution, as we can burn the seed, and it will never germinate.
To use a mixture of hydrogen peroxide for the germination process, use 1 to 2 drops of 99% hydrogen peroxide in a glass of water. After soaking for 24 hours, the outer shell is softened enough to germinate the seeds.
In addition to chemical and mechanical scarification, we can use other DIY methods to loosen seeds. For example, we can use a small knife to scratch or open the seed coat. We can explore different approaches as long as we do not damage the seed embryo.
- One part 3% hydrogen peroxide with six parts water.
- One part 4.5% hydrogen peroxide with nine parts water.
- One part 6% hydrogen peroxide with 12 parts water.
- One part 30% hydrogen peroxide with 60 parts water.
Always Use Clean, Fresh Water
Clean and clean water contains oxygen and hydrogen molecules. These are two life-supporting elements necessary for germination. Soaking the seeds for at least 12 hours allows water to enter living cells, a process known as osmosis. Now that the internal conditions promote germination, the semen embryo expands and breaks out of the protective sheath.
Old cannabis seeds sometimes pose a challenge for germination. You can sort ripe seeds, release the hard protective layer by various methods, try new chemical germination enhancers, or use biocatalysts. Similarly, soaking the clean, soft seeds in clean water will push the embryo out of its protective blanket. After trying some of the above processes to germinate the old cannabis seeds, we can be sure to grow healthy and living plants and expect good yields.
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.