Come learn how to easily grow organic cannabis at home! This article discusses soil options, seed selection, containers, and tips for ongoing care. Explore how to begin growing marijuana plants by comparing seeds versus cuttings, and learn how to acquire the seeds you need. Want to grow weed from seeds? Learn how weed seeds work, how to sex marijuana plants, and how to properly germinate your cannabis seeds.
How To Grow Cannabis Organically: Seeds, Soil, Containers & Care
The topic of “how to grow cannabis” has such a funny vibe about it. If you browse around online, you’ll see there are many cannabis growers with extremely strong opinions about “the right way” to grow cannabis, though all of their methods vary… Esoteric language, expensive supplies, and complicated recipes or instructions are often used, making it a very intimidating and confusing subject for new home growers.
I am here to hopefully take some of the mystery out of it for you! The methods we choose to use for growing cannabis here at home are pretty dang simple! Sure, there are some steps to follow and supplies to gather, but growing cannabis is not all that more complicated than growing high-quality organic food at home. Or at least that is how we approach it. All you need is rich healthy soil, a large container, and either cannabis seeds or started seedlings – called “clones”.
Read along to learn about our preferences for soil, containers, seeds, and how to get started growing cannabis at home, organically!
This article will get you started with your growing season, then check out the follow-up posts for ongoing care – with tips on routine fertilizing, organic pest control, and how to harvest, dry, and cure your cannabis too. Keep in mind that our goals are not all about high yields. The goal is to grow safe, high-quality, organic cannabis that we can utilize and enjoy with peace of mind – knowing how it was treated from “bean to bowl”. It is about quality over quantity, though we end up with more than enough anyways!
This post is intended for people living in states who are legally allowed to grow cannabis at home, either medicinally or recreationally. If you have any questions about this, please refer to your local cannabis regulations. Note that today’s post is also geared around growing cannabis naturally outdoors, so I will not touch on light deprivation or indoor grow set-ups. I do plan to write an indoor grow guide in the near future, but most of the tips in this article can easily be applied to an indoor grow too!
Where to get cannabis seeds or clones
Keep in mind that cannabis has not been legalized at the federal level – with the exception of low-THC, high-CBD hemp. Therefore, even if you live in a state that has legalized marijuana, shipping cannabis seeds and products across state lines is technically still illegal. But it is commonly done nonetheless. To my knowledge, people buy cannabis seeds online fairly easily and without issues. However, if cannabis is legal in your state, the most safe and “by the book” way to procure seed or started plants (clones) is from a licensed cannabis store.
Here are a few reputable places that discreetly sell cannabis seeds online:
– A popular ‘seed bank’ with a huge selection, including CBD! (money order only) (autoflower seeds only) (based out of the Netherlands, ships to US) (UK, ships to US)
Keep reading to the “Cannabis Growing Conditions” section below for information on exactly when and how to start cannabis seeds (or plant clones).
Feminized, Regular, or Autoflower Seeds
Cannabis comes in many shapes and sizes! Obtaining feminized seeds or plants guarantees that they will flower. Aka – they’ll grow buds. “Regular” seeds could grow up to be males. They’re pretty useless unless you want to breed plants. Any males in vicinity will pollinate your female plants, make them produce seeds in the buds, and reduce their THC development. Most people cull the males before they produce pollen to avoid this. We grow with feminized and sometimes regular seeds too.
If you do grow regular seeds, see this article to learn how to determine the sex of your cannabis plants in the early pre-flower stages. You may also want to start regular seeds a few weeks earlier than you would feminized seeds, which allows for ample time to ID the ladies (or gentlemen).
For a super-quick growing season and small, manageable plants, you could try autoflower cannabis types. Autoflowers are available in feminized, sativa, and indica options too.
Young cannabis seedlings we started from seed. If the seeds are ‘regular’ (not feminized) we usually pot them up into larger nursery pots (shown in the background on the right) until we can identify if they’re male or female. Once we identify the ladies, then they are transplanted into their final grow bags, shown on the left. If this sounds too involved, stick with feminized seeds to start!
Strains: Sativa vs Indica
Sativa-dominant plants are typically more uplifting and energizing. Sativa plants also get taller, lankier, and take longer from seed to harvest. Indica-dominant strains finish a little faster, pack on fatter buds, and are generally shorter and wider plants. These make them a preferable variety for northern climates with shorter growing seasons. Indica is also known for more of a mellow, sleepy, heavy, couch-lock kind of vibe.
We generally prefer uplifting, happy, energetic sativa-dominant hybrids – ones that are balanced with enough indica to keep things smooth, relaxing, and still make for a great night of sleep. “Maui Wowie” is a long-standing favorite here, and “Rosetta Stone” is our new go-to lately.
Beyond all of these broad categories, each strain will also have unique attributes that may make it more or less desirable to you. Find what suits your needs! What works for us may not be what works for you. To read more in-depth on the differences between sativa, indica, and autoflowers (including their health benefits) check out this post.
Autoflower cannabis plants in the greenhouse, in smaller 5 gallon smart pots. They take up far less space, and time!
THE PERFECT CANNABIS SOIL
If you checked out our post about how to build the perfect organic soil for raised beds, our methods for building the perfect cannabis soil isn’t all that different. We’re shooting for something that is rich, biologically active, full of micronutrients, and has an excellent balance between moisture retention and drainage. Reference that raised bed soil post if you want to dive deep into detail, but otherwise here is a quick-and-dirty for cannabis soil:
I’m going to give you all two options below. One is a little more involved, which is crafting your own soil from scratch. This is what we do. The second option uses pre-made soil, and requires less ingredients and steps upfront.
Either way you choose to go, please note that we follow a no-till method. That means the soil is a one-time upfront cost, aside from some amendments you’ll need on an ongoing basis. Those last a long time before needing replenishing too! At the end of a growing season, the mature cannabis plant is cut down at the soil line, and the roots left in place to decompose over the winter with the aid of worms and light moisture. The soil is used year after year in the same container, improving with age. This is also called ROLS – recycled organic living soil.
Here are two of our 25-gallon cannabis grow bags, full of recycled organic living soil. These are kept in a shed over winter (and some outside too), and kept alive with an occasional light watering. The soil is reused the following season.
Option 1: Our Organic Cannabis Soil Recipe
Combine the following ingredients. If you plan to fill several large containers (like grow bags – discussed below) then it may be easiest to mix all of these in a very large tote or even spread out on a tarp, and then add some to each bag. Note that it is best to pre-moisten the peat moss before mixing it with everything else. Peat tends to be hydrophobic when dry, and can make your soil less likely to absorb water well if it is mixed without wetting first.
- 1 part Canadian sphagnum peat moss (We often use Roots Organics or Premier – both found at our local ‘grow shop’.)
- 1 part high quality compost (We love Malibu’s Biodynamic Compost, but it’s only available on the West Coast. There is a similar East Coast option by Coast of Maine. You could use aged homemade compost, or shop around to see what is available. Maybe there is a local worm farm in your area?)
- 1 part aeration additive (We prefer 3/8-inch Lava rock, aka lava cinders. You could use pumice or perlite instead.)
Evenly mix in the following amendments:
, ½ cup per cubic foot of soil* , ½ cup per cubic foot of soil , ½ cup per cubic foot of soil , 2 cups per cubic foot of soil , 1 cup per cubic foot of soil , 1 cup per cubic foot of soil
- A handful of worm castings and a few compost worms, if possible
- Optional: Biochar, 2-4 cups per cubic foot of soil
*In the recipe above, when I mention the amendment amounts “per cubic foot of soil”, I mean the total combined volume including peat moss, compost, and aeration. Also note that all of these amendments are things we also use in the garden, and last many seasons!
Curious about what all these things are for?
Kelp meal contains over 70 different vitamins and minerals. It helps promote overall plant health, vigor, and tolerance to stress, pests ,and disease. It is also a renewable, sustainable resource – so that’s a huge plus.
Neem meal enhances microbial activity, making your soil even more alive! It also strengthens root systems, and can help control unwanted nematode populations, fungus, and soil pathogens.
Crab or Crustacean meal is high in chitin, which stimulates the soil food web and beneficial microbe activity. It may also help combat root knot nematodes. This meal contains both macro and micronutrients as fuel for the plants.
Rock Dust contains micronutrients and trace minerals that are essential for a plant’s core biological processes to work at their strongest, such as nutrient uptake and photosynthesis.
Gypsum contains calcium and sulfur, and helps the plant better utilize and uptake potassium, which is one of the key macronutrients that all plants depend on for life. In the “NPK” ratio for all fertilizers, the K stands for potassium. Adequate potassium availability and uptake enables plants to photosynthesize, produce energy and important enzymes during growth, and also assists with water uptake and drought resistance.
Oyster shell flour is an excellent source of calcium for the plants, as well as phosphorus. Adequate calcium carbonate protects plants from heat stress, makes them more resistant to disease and pests, strengthens plant cell walls, and increases nutrient uptake and overall vigor. Oyster shell flour also acts as a pH buffer.
Here is a little video of our organic living soil in action:
A note about peat moss:
Peat moss gets some flack for being not very sustainable. However, it also gets some of the best reviews and results for growing cannabis. Cannabis likes very slightly acidic soil, which peat moss naturally is. It is also an incredibly common ingredient in almost all bagged soil, so it’s hard to avoid in the gardening world. Aaron put together our soil before we were fully aware of the environmental concerns. Because we are reusing and recycling it each year, the best thing for us is to continue utilizing it!
Some people who grow cannabis choose to replace the peat moss portion of this recipe with coco coir, which is a more renewable, sustainable material. I can’t speak to its effectiveness because we haven’t used it for cannabis, though we do add a little coco coir to our raised beds sometimes, and also use it as bedding in our worm bin. Honestly, we have heard not-so-great results and read numerous studies that show coco coir has inferior performance to peat moss.
Option 2: Use Pre-amended Bagged Soil
If mixing up all those amendments sounds a little too “extra” for you, you could do the following instead:
Use mostly pre-made, high-quality, bagged organic soil. If you have access to it, try to add in a little rich aged compost, worms, worm castings, and/or aeration too! Experiment with building your own soil, with a premade base. Check out this post on how to start a super simple worm bin, if you’re in need of worm castings! They can also be purchased.
For this method, you could skip a lot of the additional amendments upfront, though you’ll still want to add some as the growing season progresses. Cannabis is a hungry plant! The choices and availability of bagged organic soil options will vary depending on where you live. If you can, get top-of-the-line stuff – it is going to be more pre-amended for you.
Examples of popular cannabis soil brands to keep an eye out for are Roots Organics products, Fox Farm’s Ocean Forest/Happy Frog, or Recipe 420 by E.B. Stone. Even some of the Kellogg or G&B Organics could work well, especially when premium compost is added. Check to see if there are any hydroponic stores or “grow shops” in your area. Those stores cater to cannabis growers, and are more likely to carry premium bagged soils over the stuff at big box nursery centers.
Now that you have a soil choice in mind, what are you going to put it in?
CONTAINERS FOR GROWING CANNABIS
We prefer to grow our cannabis in grow bags, and I’ll explain why below. If you want to stick your plants in garden beds or right in the ground, be my guest! This is just what works for us. Check out how to build a durable and deep raised garden bed here.
Benefits of Grow Bags
The preferred container for growing cannabis for many people, ourselves included, is in large fabric grow bags. As opposed to a hard-sided container, they promote better aeration, drainage, and even moisture. Solid containers like 5-gallon buckets could be used, but have the tendency to be drier on top and soggy on the bottom. Grow bags also accomplish something called air-pruning. When the cannabis plant’s roots near the edge of the bag, the exposure to air naturally prunes them back. This is a way to keep the plant happy and healthy in its given container, naturally limiting itself and keeping the roots healthier. In contrast, a solid container allows the plants roots to continue to grow in circles around the container and themselves – becoming root bound. This is not a good thing.
Grow bags are great because they allow people to grow cannabis in a variety of living situations, be it on a patio, indoors, or in a greenhouse. By using a container, you have ultimate control over the soil you choose to fill it with.
Additionally, you can make them mobile! We make rolling dollies to sit all of our cannabis grow bags on, out of 2×6’s and heavy-duty casters. See the photos below. That way, we can easily roll or rotate the large (and heavy!) plants out of our way or into better sun as needed. If you do the same, make sure you get casters that are rated for at least 50 to 80 pounds of weight per wheel, minimum. Ours are 2″ and okay for the flat patio, but 3-inch wheels probably would have made it even easier to move.
Our DIY dollies with casters. Three redwood 2×6 boards are held together by a supporting 2×4″ in the opposite direction, screwed into each board. To catch runoff, we use large plant saucers. This one is 25-inches (top rim to rim) and can hold the 25-gallon grow bags that are 21″ at the bottom. Lava rock is sitting in the bottom of the saucer to keep the grow bag from sitting in standing water.
Grow Bag Brands and Sizes
The bags we prefer to use are the Smart Pot brand, or GeoPot. These are extremely durable and long-lasting. You get what you pay for. We have used cheaper grow bags in the past and they rip and degrade within a season or two of use. Smart Pots will last for years and years. We have bags that are three years old and still as good as new. Call me silly, but I also love being able to choose tan or brown colored bags. I like a pretty garden space and prefer the look of those to the stark black choices.
The size of your grow bag will dictate the size of your cannabis plant, and its health. Obviously, the size of your space will determine how big of bags you can use too. The smallest I would suggest for a traditional photoperiod plant is about 15 gallons. We generally use 20-gallon or 25-gallon bags for those big girls.
If you have a lot of room and want really large plants, you could go even larger! On the other hand, if you are growing autoflower cannabis plants, a 5-gallon or 7-gallon bag would work just fine. Not sure what the difference between a photoperiod and autoflower cannabis plant is? Check out this post that explains it all.
Okay, we have our soil and our bags… now on to the most important part of this post: the cannabis itself.
See how big they can get? Those are our Maui Wowie girls. Also note the DIY dolly below the grow bags. We can easily roll them aside when we want to enjoy our patio space, and put them more in the middle when we’re not outside.
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CANNABIS GROWING CONDITIONS
In most places, cannabis seeds are started indoors in March or April, and transplanted outside in April or May once the risk of frost has passed. Basically, cannabis seedlings need to be protected from freezing or other harsh conditions – just as any other seedling does! If you aren’t sure about your area’s frost dates, stop by this article. In it, I share veggie seed-starting calendars for every USDA hardiness zone. For cannabis, you can essentially follow the timing recommendations for tomatoes (but on the later end of the given windows).
Depending on the strains you are growing and your summer daylight hours, the average cannabis plant will continue to grow larger in size (in its vegetative state) until the days begin to shorten and it receives less than 12 hours of sunlight per day (e.g. after summer solstice). Then, it switches into its flowering stage and begins to develop buds. Most outdoor cannabis plants will be ready to harvest in September to October. The exception to this would be for autoflowers, which can start and finish their entire life cycle in as short as 3 months.
Starting cannabis from seed
We prefer to grow from seed. Once we obtain seeds, we treat them pretty much like any other garden seed! They’re germinated in 4” pots full of seedling start mix, inside on a heat mat. Keep the containers covered and moist until they sprout. Ideal germination temperature is around 75-80 degrees Fahrenheit.
After sprouting indoors, cannabis seedlings need strong bright light – such as that provided by a supplemental grow light. Unfortunately, a sunny window will not provide enough light, and the plants will get extra tall, weak, and leggy. Once our seeds pop indoors, we move the cannabis seedlings to our greenhouse for a few weeks before going fully outside. We also use lights for growing autoflowers in the off-season in the greenhouse. (See this article for more information about choosing and using grow lights.)
To read more in-depth information about how we start seeds, check out our seed starting 101 post!
Cannabis seedlings in our greenhouse, being treated just like the peppers, eggplants, and other garden plants!
Note that you do not need a greenhouse or fancy supplies to start cannabis! If you don’t have a heat mat, I suggest pre-soaking the seeds in non-chlorinated water overnight before planting. This will aid in germination. In lieu of seedling start mix and little pots, another option is to germinate the seed inside a moist root riot cube, then plant the whole cube in its final grow bag after it sprouts. If you aren’t equipped to raise seedlings indoors for several weeks, plan to start in late April to early May. Most locations will be adequately warm enough by then for the seedlings to go right outside after germination (or to sow seeds directly outside, if you wish).
Once they’re a few weeks old and the weather is right, we transplant our seedlings outside to their final large grow bag. When they are transplanted, we sprinkle some mycorrhizae in the planting hole and on any exposed roots. Mycorrhizae enhances nutrient uptake, and disease and drought resistance. If you did have your seedlings indoors under lights for a few weeks, don’t forget to properly harden them off before moving them outside! This helps to strengthen them and prevent transplant shock.
If you are growing from clones instead (such as those you purchase at a local dispensary, or obtain from a friend), you can skip straight to potting them into grow bags outside.
Some young cannabis plants, recently transplanted into their final large grow bags. The small support stakes will be replaced with larger ones as they grow.
Sun and Support
Full sun is best! If you have a wide open location that receives full sun all summer and into fall, you’re in luck. We have changing sun patterns, with some shade from our house and trees to contend with. That is the beauty of putting the grow bags on dollies – we can move them around to receive the most sun possible as the seasons change.
Provide support for the main stalk with a sturdy stake. As the plant gets larger and starts to put on bud weight, you may find the need to further support individual branches. This will depend on the strain. Some growers get crazy with their support and training systems! We start with a small stake for seedlings (shown above) and then swap it to a 5 or 6-foot tall stake as the plant matures.
In regards to water, the goal is to provide consistent, even moisture. Do not let the soil completely dry out between watering, but don’t drown it out either. As with many things, this will vary a lot depending on your climate. If you’re in a very hot and arid place, you will need to water more frequently than someone in a cooler coastal climate like ourselves.
As the plant grows and the root ball gets larger, it will drink water faster and therefore need more, and more often. I will write a follow up post about watering and fertilizing (which often go hand-in-hand) throughout the growing season soon.
If possible, use dechlorinated water. It isn’t a deal-breaker, but the plant and soil microbes will definitely appreciate it. If you are on city tap water, allowing a bucket of water to sit out overnight can help the chlorine dissipate. We mostly use our captured rainwater. Another option is to use a simple hose carbon filter to remove chlorine.
Mulch the top of your grow bag to maintain a healthy soil. We love using biodynamic accumulators that not only provide moisture retention, but will later break down into more nutrients and energy for the cannabis. Some examples of biodynamic accumulators are borage, comfrey, yarrow, and dandelion greens. Fava bean greens are also excellent for green mulching, since they’re nitrogen fixers! If you don’t have access to these types of plants, straw or hay will work.
I don’t know about you… but to me, that mulch is looking super sexy! Yarrow, comfrey, borage, lavender, dandelion greens, and straw.
Another popular mulch option is to use an organic cover crop seed mix, and lightly working it into the top inch of soil when you first plant your cannabis seedling. As it gets watered, cover crop will grow under the canopy of your plant. It becomes a living mulch, and also enhances your living soil food web. As it grows tall, you can “chop and drop” mulch with it. That is when you trim it and leave it in place to decompose as green mulch.
And just like that, you’ve given your cannabis a stellar start! You’ll be enjoying your own homegrown organic bud in no time.
Once you have your cannabis off to a strong start, come learn about the ways we routinely fertilize our plants! Also, how to keep the pests at bay:
- “How to Feed Cannabis, Organically: Top-Dressings, Teas & More”
- “Organic Cannabis Pest Control: How to Keep the Bugs Off Your Nugs”
Last by not least, when the time comes, here an article all about processing your cannabis: “How to Harvest, Dry, Trim, Cure, & Store Homegrown Cannabis: The Ultimate Guide”. When IS the time right to harvest? You’ll learn that here too. This guide is basically everything you need to know, from the best timing, temperature, humidity, methods, and more.
Once you have your homegrown goodies properly dried and cured, it is all ready to use: whether you like to smoke or vaporize your cannabis (read this important article on the subject), make cannabis-infused oil for edibles, homemade cannabis tinctures, or create healing topical salves. The options are endless!
I hope this all took some of the mystery out of growing cannabis for you. Please feel free to ask questions and pass this post along. To the left, of course. Wishing you the bet of luck with your growing adventure!
How to Grow Marijuana from Seed
If you’re in a location where cannabis (another term for marijuana; short for the plant cannabis sativa) is illegal, growing it is probably illegal too. Bringing in seeds or cuttings to your location can very well be a felony, and reputable sellers won’t ship to you.
You can probably purchase and grow hemp seeds and plants, which have a negligible amount of THC, but these plants won’t produce the psychoactive effects of plants that contain higher levels of THC. Check with your seller to be certain you’re getting what you think you’re purchasing. If you buy seeds for CBD-only hemp plants by mistake, you can end up being very disappointed post-harvest.
How to acquire seeds or cuttings
You can usually find cannabis seeds for sale at most dispensaries in areas where growing cannabis for personal use is legal. You may also find growers who sell cuttings/clones. You can expect to pay $50 to $100 for a pack of ten seeds. When shopping for seeds or cuttings, read the labels and any other information the manufacturer provides on its website or in its catalog to make sure you’re getting the right seeds or cuttings (the strain) for the plants you want to grow.
One way to get your mitts on some seeds is to collect seeds when you find them in flowers you purchased, or get some from friends if they’re collecting.
- Feminized seeds: Nearly all seeds sold by reputable companies are feminized, but make sure they are. These seeds are specially treated to grow into female plants.
- Auto-flowering or photoperiod: Auto-flowering plants are easier, because they enter the flower stage after a certain number of weeks regardless of the light/dark cycle. If you’re a beginner, seriously consider going with auto-flowering plants.
- Genetic background: If seeds are from a well-established strain, such as O.G. Kush, Bubble Gum, or a cross-breed, the genetic background should be stated.
- Blend: The blend represents the percentage of the three species — sativa, indica, and ruderalis. All auto-flower strains contain some percentage of ruderalis, which is responsible for the auto-flowering nature of the plant.
- Yield indoors: The number of grams of bud per square meter of plant when grown indoors.
- Yield outdoors: The number of grams of bud per plant (after drying) when grown outdoors.
- Plant height indoors: Shorter than when grown outdoors.
- Plant height outdoors: Taller than when grown indoors.
- Time to harvest: Approximate number of weeks after germination the flower should be ready to harvest.
- Potency: Percentages of CBD and THC.
- Effect: The type of experience you can expect when consuming product from the plant.
Know the laws about buying cannabis
- In some European countries, laws prohibit growing cannabis, but seed is legal, which is quite confusing. You’re allowed to buy and eat cannabis seeds because they’re non-psychotropic, but you can’t buy them to grow cannabis. Other countries in Europe, such as Germany, have their own seed laws.
- In Canada, where cannabis is federally legal, seeds can be shipped across provincial lines.
- In the U.S., in some states in which cannabis is legal, you can purchase seeds from some dispensaries or other locations to grow plants as long as you keep them in the state. Other states may bar selling to non-licensed growers. Shipping or transporting seeds across state or international borders is illegal, although a few reputable online seed stores ship to individuals with success.
Cuttings are typically treated in a similar manner as seeds in legalized locations. They may be available from some dispensaries or outlets for pick up or delivery with a fee. They’re prohibited from crossing U.S. state lines or international borders. You can buy individual plants and mix and match strains. Prices vary and are often determined by plant size.
Buy cuttings (clones) only from a reputable source who understands proper back-crossing of strains for stability. Back-crossing involves pollinating a plant with one of its parent plants to promote sexual stability, so that when you have a female it won’t hermaphrodite into a male during flowering.
Both seeds and clones are often able to be purchased from commercial locations already in your state.
In the U.S., transporting any part of the cannabis plant over state lines is illegal. This applies to seeds and clones and, technically, even to tissue samples.
How to germinate cannabis seeds
Germinating seeds requires a dark environment that is around 70 degrees. There are many ways to germinate seeds (in soil, in a wet paper towel, in starter plugs) You can also sow them directly into soil in a garden or container, as long as the soil is light and fluffy, so the roots can easily grow down and the stalk can break through the soil. Plant the seeds about 1/4- to 1/2-inch deep and cover them loosely with soil.
Most importantly, seeds need a moist environment; they won’t germinate if they get too dry. You can use a heat mat to increase the success of germination in colder climates.
How to transplant marijuana plants
When transplanting any plant, whether it started from seed or a clone, handle it gently, being very careful not to damage the roots. Center the plant in the pot, and plant it deep enough to cover the root ball completely in soil. If the plant is root bound, you can gently tease the roots apart to encourage outward growth.
Pack your soil or other grow medium down around the roots well enough to support the plant while new roots grow, but not so tight that the soil restricts outward root growth. Water the soil around the roots.
About This Article
This article is from the book:
About the book authors:
Kim Ronkin Casey has been a communications professional for more than 20 years and recently took a year-long leap into the world of cannabis as the communications manager for one of the leading dispensaries in North America. She now consults for companies in the industry on internal and external communications. Joe Kraynak is a professional writer who has contributed to numerous For Dummies books.
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.