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Growing a cannabis seed crop

Growing Cannabis: From Seed To Harvest

Welcome to the sequel to my first post on growing cannabis at home. In it, I explained what you need to get set up for your very first weed grow. After that, you ordered your perfect seeds to work with. That means we’re all ready to roll up those sleeves and get growing! Your weed plants will go through a lot between the moment your seeds germinate and that first taste of your harvest. In this blog, I’ll discuss the stages you’ll go through before you get to enjoy the fruits of your very first cannabis grow at home!

Nibameca

Looking for genuine first-hand grow expertise, sleeves rolled up and boots in the mud? You’ll find plenty in our Nibameca blogs & grow guides ! Ever since discovering White Choco genetics, this cannaboss refuses to leave our AG grow program – and rightly so. This veteran grower is all about top quality, innovation and sustainability in indoor grow projects. This Amsterdam Genetics Grow Guru shares his experience with our readers to make the most out of every weed seed you’ll ever plant!

Baby Steps: Germinating Your Weed Seeds

When growers receive their Cannabis seeds, it is time to germinate. Germination is the first step of the real growing adventure: so far, everything was just preparation. Once a cannabis seed germinates, its protective shell cracks open, and the first tiny root peeps out. For the sentimental grower, this is an emotional moment – a bit like childbirth, actually. It’s also a moment, however, to be very delicate in handling cannabis seeds.

Personally, I prefer the following high success rate germination procedure. I take a glass of lukewarm water and gently chuck in the seeds. Then, I leave them alone someplace dark for 12 to 24 hours. I check them regularly: as soon as I see white tips (taproots) emerge, I carefully pick up the seed with a pincer. I place them root-down into a pre-watered grow plug. I use a water and root stimulator mix following user instructions. Then I put the plug and seed in my propagator and patiently wait for them to surface.

You’re probably thinking: grow plug? Propagator? Root stimulator? What?! No worries: germinating is 100% natural. All cannabis seeds really need is light and water. Check out my preferred germination method here, or follow this grow guide to plant germinated seeds directly into the soil. Find out what works best.

Germinated and planted: your grow is good to go!

From Germination To The Growth Stage Of Your Very First Cannabis Home Grow

After germination comes the vegetative or growth stage of the cannabis life cycle. In indoor conditions, the plants will keep on growing as long as they get 18 hours of light. This is a 16-8 lighting regime (18+6=24, i.e., a whole day). Autoflower strains are an exception; these switch from growth to flowering automatically.

Once the seeds become seedlings, with roots showing on the sides and bottom of the grow plus (usually after about four days), they’re ready for planting. I start with small P9 size flower pots. I’ll leave them for 7 to 11 days to give the roots time to develop, creating a stable habitat.

The growth stage begins.

The next step is transferring them to the full-sized grow tent. Time to repot adgain: choose a flower pot that matches your approach and available space. In my case, that’s 18 litres.

I continue the growth stage until I’m happy about plant size. It usually takes about three weeks, but my perfect size will differ from your ideal dimensions. It’s all up to you, and when you’re done, it’s time to start growing flower buds. Let’s start the flowering stage!

From Growth To Flowering

The flowering phase is where the actual magic happens. At this point, your home grow will start developing the (flower) buds containing the THC, CBD and other useful compounds. You can initiate the flowering stage by making your plants believe the calendar has moved past its midsummer peak. How, you wonder? Easy: just make the days shorter! Grab your timer and change the lighting settings from 18 hours of light and 6 hours of darkness to 12 hours of light/ 12 hours of dark. There you go; you’ve just started late summer in your tent! After about 8 to 12 days, you’ll see the first flowering hairs or pistils emerge. That’s a good sign: your plants have started flowering.

The transition from the growth to the flowering stage is marked by serious stretching. The cannabis plants soar up to the tent roof; some strains can triple their height at this point. Take this into account to make sure your plants fit your grow space.

Keeping Your First Cannabis Home Grow In Check

There’s all sorts of techniques to keep plant size under control.

LST, or low-stress training, simply amounts to bending and fixating your plants. This ensures maximum grow surface spread and enough light for optimal flowering across all branches.

Sea Of Green (SOG) allows you to grow more plants per square metre. You switch to 12/12 lighting early, creating a ‘sea’ of flowering buds.

SCReen Of Green (SCROG) instead accommodates fewer plants per square metre. Bending branches allows you to weave them through a screen or wire frame. That improves light distribution, allowing for SOG-like results using fewer plants in the same space.

Don’t Wake The Neighbours

Well, you’ve made it: at this point, your cannabis plants are in full bloom! Some strains have a 7-week flowering phase, while other flower for up to 14 weeks. Decide what you want before you start. Keep a tight grip on your grow climate in the flowering phase. If it gets too cold, bud development stagnates. High air humidity invites bud rot, mildew, and other pests to ruin your harvest.

Personally, I just love the flowering stage. You can watch the buds develop, rewarding your hard work so far. Still, the flowering stage comes with its own particular risks. As your budding colas flower, the lovely aroma of fresh weed spreads. Of course, we don’t want to share that with neighbours and passers-by. That stresses the need to use proper filtering with exhaust fans and carbon filters. Here’s a helpful tip in case you can’t control the stink, or if your power blacks out: always have a bottle of vinegar handy! In case of emergence, put a pan of vinegar on the cooker. Yes, it smells awful, but the vinegar stench will also neutralize the odour of your weed!

Harvesting And Trimming

Indeed, we’ve been saving the best for the last: harvesting those plants to find out how much they yield! It’s almost time to start trimming. At this point, keep the air humidity n your tent between 30 and 45% to prevent fungi and bud rot issues. You don’t want to lose all that hard work right before the finish line!

Can I Trim Yet?

As the flowering stage draws to a close, keep watching your trichomes. Trichomes are the little ‘crystals’ glittering on the buds and the small sugar leaves around them. In fact, they’re not crystals, but resin glands. They hold all the active compounds we’re after. Trichomes clearly indicate when it’s harvest time.

A small, cheap USB pocket microscope or a jeweler’s lens are great for determining trichome maturity. Clear transparent trichomes are a sign to wait some more. Once they turn milky white, with a few amber-coloured trichomes among them, you’re ready to cut the flowers. Harvest time is finally here!

Trimming And Drying Your First Cannabis Home Grow

Harvesting and drying your buds can be done in various ways as well. You can let the buds dry first and trim them later, but some prefer to do it the other way around. In that case, branches loaded with buds are hung upside-down in the tent to dry before trimming. The downside is that your precious trichomes dry out, making them brittle and easy to lose while trimming.

That’s why I prefer to trim first, and then drying the buds in a drying net in the same room where I grew them. I allow fresh air into the tent and keep it flowing to cut mold risks. The buds take two to three weeks to dry.

With the lights off, drying net in place, and exhaust fan running at 50%, air humidity slowly drops. Your buds are dry as soon as bending branches makes them snap.

Curing Your First Cannabis Home Grow

Now comes the last stage: curing your cannabis and processing the trimmings. Never just dump your trimmed leaves in the bin; use it for good. You can make hash or delicious edibles from what’s left over: this plant has more to offer than buds alone!

After drying, I carefully remove all the buds from the nets and place them in glass mason jars to cure. The buds cure gradually, improving their taste and ‘maturing’ them until they are perfect for smoking. Curing buds is a straightforward affair: simply stick them in a jar and wait. Give them time to ‘burp’, though: open them for a few minutes to refresh the air inside and return them to their dark storage location. How long you cure is matter of personal taste. I personally cure my weed for one month before that sweet day arrives: time to smoke those fabulous Amsterdam Genetics! Let’s not kid ourselves here: this is what we’ve been working so hard for, isn’t it?

Let me conclude with a personal warning: try to curb your enthusiasm! Of course you’re proud of your results, and you should be! Still, avoid the mistake of telling taal tales to your friends. Keep your hobby to yourself, just like back when you started out. Oh and another thing: you now probably have more weed lying around than ever before. Don’t go and smoke your brains out now; handle your harvest responsibly. Well-cured cannabis will last for a long time. Enjoy your crop, but enjoy it responsibly.

Nibameca’s Final Thoughts

I hope I helped you make the best start at managing a first ever cannabis home grow! I wish growers all the best and lots of fun, as well as heaps of homegrown weed of course. Should anything go wrong along the way, then don’t despair. I’ve run into some minor setbacks myself – and major ones too.

My biggest mistake ever was leaving the lights on after flowering in the room where I set up my tent. Sadly, the tent wasn’t light-proof, so my plants got stressed out and turned into hermaphrodites. The result: a whole harvest full of seeds that was no use at all… Fourteen weeks of work down the drain! I also made the mistake of pumping out my entire 60L nutrient mix tank in one go once. Pretty bad for plants capable of handling 10 litres at once max…

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The germination of cannabis seeds is illegal in most countries. Amsterdam Genetics cannabis seeds are exclusively sold as collectable souvenirs to customers living in countries where the cultivation of cannabis is illegal. All information on this website is intended for educational purposes only and is not meant to incentivize people to engage in illegal activities.

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
  • Haze
  • Afghan
  • GSC (Cookies)
  • Skunk
  • Cheese
  • Gelato

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.

Climate considerations

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.

Training plants

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
  • Seeds
  • Distilled water

Step 1

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.

Step 2

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.

Step 3

To create a dark, protected space, take another plate and flip it over to cover the seeds, like a dome.

Step 4

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.