Growing regular cannabis seeds indoors
Contrary to popular belief, growing regular marijuana seeds (in which we find male and female plants) isn?t more difficult than growing feminized seeds. They are accessible for everyone, also for beginners. Until early 2000, everybody learned to grow marijuana using regular seeds and the selection of female and male plants was just another step of the grow, something fast and simple to realize, such as the germination process or switching the photoperiod.
Conspiracy Kush from TGA Subcool
Naturally, 50% of the regular seeds are males and the other 50% are female plants. Of course, several factors can alter this ratio, but if using more than 10 seeds it’s almost impossible not getting a single female plant (the chances of getting 10 males out of 10 seeds is lower than 1:1000). Some people think that environmental conditions might influence on this male / female ratio (good conditions usually bring more females), but this theory hasn’t been verified in a rigorous way yet.
So, generally we recommend you to germinate 15 or 16 regular marijuana seeds for every square meter in small flowerpots. Grow them for few weeks and then switch to bloom, right before removing the males and transplanting the female marijuana plants into the definitive containers. Normally, we use 6-10 plants per square meter during the flowering stage.
In this article we will show you a grow report of 16 regular seeds using a 90 x 90 cm (or 81 m2) grow tent. The crop took around 3 months (from early October until late December). We gave our plants a growth period of 3 weeks and, approximately, 10 weeks of flowering.
Equipment for the crop, nutrients and marijuana strains
This indoor crop was performed in a DarkRoom V2 90 grow tent, with a 400W HPS bulb for the flowering phase. We used organic nutritients from the following brands: Aptus, General Organics, BAC and Cannabiogen:
- Growth Fertiliser: Bio Thrive Grow (General Organics)
- Bloom Fertiliser: Organic PK Booster (BAC)
- Growth Stimulator: Start Booster (Aptus)
- Bloom Stimulator: Top Booster (Aptus)
- Regulator (Aptus)
- Delta 9 (Cannabiogen)
Feeding chart for this crop
The beneficial fungus Trichoderma Harzianum, which grows in symbiosis with the roots of the marijuana plant, was used in each watering throughout the crop. We would like to stress the importance of using Trichoderma from seedling and also after each transplant. Trichoderma allows you to protect the roots from attacks of fungal pathogens and improve the nutrient uptake by the roots.
The Organic PK Booster from BAC contains P&K (Phosphorus and Potassium), as well as Nitrogen (N) and all the essential micronutrients needed by the plants, so it?s possible to use it as complete organic flowering fertiliser for your marijuana plants. It also contains sugars (molasses) and other interesting natural ingredients.
We used Light Mix with a bit of Bio Super Mix to enrich the soil composition. The chosen cannabis strains to grow were:
- 8 regular seeds of Conspiracy Kush from TGA Subcool, a mostly Indica cross between Obama Kush and Space Queen.
- 8 regular seeds of 818 Headband from The Cali Connection, a hybrid of Sour Diesel and OG Kush, two famous geneticsfrom USA.
Germination of cannabis seeds
16 marijuana seeds were set to germinate between two dishes, using paper towels moisturized with water and Trichoderma.
Germination of cannabis seeds
You should make use of the microbial life as soon as possible so that the symbiosis will be effective from the beginning and the small radicle is protected against the attacks of fungi and diseases such as the Phytium or wilting. Normally, it will be possible to observe the development of the Trichodermas on the roots.
Keeping the temperature between 20 and 25° C, 100% of the seeds sprouted within 48 hours. They were planted into 3 litre pots during approximately 3 weeks of growth. It?s possible to use smaller plant pots during the first days of the plant’s life to create a more dense and effective root system.
Seedlings beginning their life
Growth of cannabis plants
From the beginning of the growth period we could observe traces of thrips in the youngest leaves, noticing the silver dots typical of this pest. We soon used a treatment using biological insecticides, spraying the plants with this mixture:
- Azaprot (Neem Oil) 2 ml/L
- Pireprot (Crisanthenum Pyrethrum Extracts) 2 ml/L
- Cinnaprot (Cinnamon extract) 2 ml/L
- Alliumprot (Garlic slurry) 6 ml/L
If you want, you can replace the Azaprot, Pireprot and Cinnaprot from Ecoprotec for Trabe’s Ain THC, Expelex and Bio Fungi C Grow.
Cannabis plants after 6 days of growth
Generally, when using natural insecticides, we recommend mixing different active ingredients to prevent insects, diseases or mites, thus improving the plant resistance from the start. This mixture allows you to fight with natural methods against a great diversity of insects and mites, using it either as preventive or to erradicate pests.
Cannabis plants after 12 days of growth
During the second week of growth, we stimulate the vigour of the plants spraying 5 ml/L of Delta 9 from Cannabiogen, a product rich in vitamins, amino acids and nutrients. After around 15 days since the beginning of the plants life, we start adding growth fertiliser (Bio Thrive) to the nutrient solution, gradually increasing the dose while looking for nutrient excesses.
Cannabis plants after 16 days of growth
During the last week of growth (3rd week), we apply another insecticide treatment before switching to bloom. At this point, we prune the tops of the plants to keep their vertical growth under control, what will also be beneficial for the development of side branches.
Cannabis plants after 21 days
During this growth period, the temperature varied between 22 and 31 ° C, while the humidity level was between 40 and 70%. At early Autumn the weather can be really hot in Spain, and the humidity level raised as the plants grew.
Pre-flowering of cannabis plants (weeks 1 and 2 of flowering)
The growing space was full and it was time to switch our plants into the flowering phase, reducing the growth photoperiod – 18 hours of light per day (18/6) – to 12 hours of light per day (12/12).
We divide the flowering stage in three consecutive phases, and each phase must be performed perfectly to ensure a good harvest. These phases are: the stretch, the bud development and the final ripening of the plants, the last stage before the harvest of marijuana plants.
When we switch to 12/12, the stretch period begins and plants grow notably until reaching their final height, a phenomenon comparable to the adolescence of humans. During this period, cropping the branches of the higher plants – trying to keep them as uniform in height as possible- is advised.
Cannabis plants after 4 days into flowering
While marijuana plants are normally very vigorous and very resistant during the flowering period, this is a crucial moment for them and the grower should take care of their needs properly: if you don’t look after your plants during this stage, you will take the risk of creating a jungle very difficult to control once in full bloom, especially when working with different genetics.
The watering and feeding needs (especially Nitrogen) must be accurately met during the stretch of plants, so we must pay close attention to prevent any drought or deficiency which would slow down the overall plant development. During the transition to flowering, we used again Delta 9 from Cannabiogen (via foliar), to help and stimulate the plant metabolism during this important stage.
Cannabis plants after 8 days into flowering
Few days after switching to 12/12, we could already identify the female plants for the two pistils (white hairs) that develop on the internodes of the branches, so we could easily identify and remove the male plants, which develop very different flowers, shaped like small clusters or sacks.
In this crop, we got the following number of males and females:
- Conspiracy Kush: 7 female plants, 1 male plant
- 818 Headband: 3 female plants, 5 male plants
Thus, we had 10 female plants to flower, which were quickly transplanted into 7 litre pots. We pruned the lower parts of the plants to favour the top parts, which are more exposed to the light. These small branches were rooted as cuttings in a small propagator (during the growth cycle, 18/6), so we could keep an exact copy of each grown female.
After the harvest, the tasting will allow us to choose the best female according to our criteria (taste, smell, effect, yield, resin production, resistance to pests, etc.) and keep them as mother plants, so we can grow the same plant again and always with the same traits. Indeed, regular seeds are the perfect option for selecting mother plants.
Cannabis plants after 15 days into flowering
Right after the end of the stretch, all plants were treated for the last time with a biological insecticide. If you want to make your own regular seeds, you can also select and keep the best males in a separate space. If you don’t want to make seeds, then you should remove them as soon as you identify them to avoid that they release their pollen and get your plants seeded.
During the stretch the temperature ranged from 21ºC to 28ºC and the humidity level was between 40% and 60%.
Cannabis plants in full bloom (3rd and 4th weeks)
As soon as we see that our plants are starting to develop buds we can stop using growth fertiliser and root stimulators, which will be replaced for nutrients and boosters formulated for the flowering stage.
Cannabis plants after 3 weeks into flowering
A third and last application of Delta 9 will stimulate the metabolism of the plants for the next weeks. The stretch phase has finished, except for one 818 Headband from The Cali Connection plant that keeps on growing. We continue cropping it regularly and place it on a corner of the growing space.
The flowering was slowed down due to low temperatures, so we added heat cables around the pots: the roots of cannabis plants are sensitive to cold and we must warm them if necessary. Just like us, marijuana doesn?t like cold feet. We decrease the potency of the extraction fan with the help of a power controller to keep the heat produced by the lamp in the growing space.
After these changes, the temperature ranged from 12 °C (light off) to 20 °C (light on) and humidity ranged between 50% and 70%.
Cannabis plants after 4 weeks into flowering
At this stage of bloom the buds are beginning to develop a considerable amount of resin, and the smell is more and more intense, so using carbon filters is advised if you want a discreet crop.
Peak of flowering (5th and 6th weeks)
At this moment, the Conspiracy Kush plants from TGA develop beautiful bluish colors favoured by the low temperatures during the night periods. We keep on using our feeding schedule and any plant shows symptoms of deficiencies during this stage, in which the buds fatten up day by day.
Conspiracy Kush after 35 days into flowering
Once into flowering, marijuana plants need very little maintenance, but we should look with diligence for the presence of insects, mites, fungi, deficiencies and excesses or hermaphrodite plants.
At this point, the temperature ranged from 14 to 25° C and the humidity from 50 to 70%. In some Conspiracy Kush phenotypes the resin production was excellent, as well as the superb scents released by the more resinous plants.
41 days into flowering, we start flushing the roots (weeks 7 and 8)
Flushing the roots of cannabis plants (7th and 8th weeks)
The dosages of the nutrients and boosters used have been progressively reduced so that washing the roots of the plants is performed more progressively and effectively. The plants will now use the nutrient reserves they’ve kept in their tissues, principally in the leaves but also in other parts of the plant. Flushing the roots highly improves all the aspects of the final product, improving both the organoleptic features and its medicinal properties.
47 days into flowering
At this stage, the buds stop growing; the plants start their ripening process, the last stage of the flowering period; the flowers develop more and more terpenes and trichomes. During this period, the temperature ranged between 14 and 25 °C with a humidity level from 50 to 70 %.
54 days into flowering
End of flushing and harvest (9th and 10th weeks)
During the end of the flowering satge, when plants come to the end of their life cycle, we will use only water – without fertilisers – to perform a more rigorous root flushing. The chlorophyll breaks down and the plants lose their green colour: if carotenoids predominate, the plant will turn into yellow colors, but if the anthocyanins dominate – a natural pigment present in blue varieties which appears due to low temperatures as a protection from the cold) the marijuana plants will turn into a beautiful purple/bluish colour.
9th week into flowering
During this period it?s also important to be patient and to observe the resin glands on the buds, waiting for the ideal moment to harvest our plants. Normally, we will harvest them when most the resin glands are white/milky and only few amber trichomes are present, a sign that THC is starting to degrade into CBN, a cannabinoid which has only 10% of the psychoactive effect of THC.
The temperature ranged from 14 to 25 °C and the humidity from 50 to 70 %. The smell of the plants is amazing, constantly producing the aromatic terpenes typical of cannabis plants.
70 days into flowering, plants are ready to harvest
Drying and curing cannabis buds
During the harvest, each plant was carefully examined looking for molds. Fortunately, and despite having a relative humidity rather high during the bloom phase, any plant was attacked by fungi. A good ventilation, and the regular use of Trichoderma during the growth stage greatly helped to avoid the risk of mold on the buds, which often start growing in the substrate.
We discovered few male flowers in one of the 818 Headband plants, but they certainly were sterile because we never found any seeded bud.
The drying process was performed in a dark place, with a constant temperature of approximately 15 °C and during 4 weeks. A long drying process demands more patience, but surely rewards the grower with superior organoleptic quality.
Harvested Cannabis buds, Conspiracy Kush and 818 Headband
The small leaves of the buds, completely covered with resin glands, were trimmed after drying and kept to make high grade homemade hashish. The buds were stored in glass jars and opened every day for 30 minutes during around 3 weeks, until being properly cured; this crucial final stage is called curing.
The grower estimated a yield of 25-30 grams per plant, a total of 250-300 grams.
Smoke report of Conspiracy Kush and 818 Headband
If speaking about the cultivation of these strains, we liked the Conspiracy Kush better than the 818 Headband, mainly due to its beautiful purple colours and impressive production of resin glands, a characteristic trait of all TGA Subcool strains. These are easy to grow genetics, with a relative stability between females, what suggests a great predominance of the mother Obama Kush in this hybrid. The 818 Headband is more vigorous, especially during the stretch stage, developing more side branches and yielding a bit more.
Smoke report of Conspiracy Kush from TGA Subcool:
- Appearance : Great bag appeal, compact buds with a nice layer of resin and beautiful green/purple colours. The small leaves of the buds are covered with resin and produce excellent hashish. Score: 5/5
- Flavour : Conspiracy Kush produces a very soft smoke when inhaling. We will notice hashy and fruity notes – reminiscent of grapes and berries – with lemony undertones. The fruity and sweet flavour increase as the curing process advances. We will see some differences from one female plant to another, but they all have very similar taste. Score: 4/5
- Effect : The effect is mainly body relaxing, typical of Indica marijuana strains, although it isn?t a couch-locking high. This variety is perfect to fight against stress, insomnia or to relax after a hard day of work. Score: 4/5
Smoke report of 818 Headband (Sour Diesel x OG Kush) from The Cali Connection
- Appearance : 818 Headband buds compact, but not as Conspiracy Kush’. The flowers are light coloured and resin production is above average. Score: 4/5
- Flavour : Sour Diesel notes mixed with earthy undertones inherited from the OG Kush. The smoke is harsher than Conspiracy Kush, less refined in respect of aromas. Score: 3/5
- Effect : The 818 Headband produces a powerful and balanced effect between high and stoned, starting with a relatively strong cerebral effect that quickly becomes a more relaxing experience. Thus, it is a good choice for those who are seeking a balanced effect, suitable for the day but also before going to sleep, for medicinal purposes or simply to enjoy the plant recreationally. Score: 4/5
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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.