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!
Let’s dig in.
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:
- Homegrown Cannabis Co – A popular ‘seed bank’ with a huge selection, including CBD!
- Great Lakes Genetics (money order only)
- JBC Seeds
- DC Seed Exchange
- Neptune Seed Bank
- Mephisto Genetics (autoflower seeds only)
- Nirvana (based out of the Netherlands, ships to US)
- Attitude Seed Bank (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.
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.
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.
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:
- Kelp meal, ½ cup per cubic foot of soil*
- Neem meal, ½ cup per cubic foot of soil
- Crab or Crustacean Meal, ½ cup per cubic foot of soil
- Rock Dust, 2 cups per cubic foot of soil
- Gypsum, 1 cup per cubic foot of soil
- Oyster Shell flour, 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.
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.
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!
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.
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.
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!
Hi there! I have been loving your site since my sister directed me here last fall. Just wondering what your thoughts are on topping cannabis plants? If and when?
Aaron (Mr. DeannaCat)
Hi Ruth, we are so glad you found us and are enjoying the website! Are you growing indoors or outdoors? Indoors, we typically always top plants but outdoors we like to see their natural shape. I think the last plant I topped outdoors was above the 8th node give or take, usually outdoor harvests are more than sufficient whether you decide to top your plants or not, if you are growing more than one plant, top one and leave one un-topped and see what you like best. Hope that helps and have fun growing!
Hi Aaron, thanks for the help. I am growing outside and love your suggestion to top-one-leave-one and see what results. That I will do! Happy growing!!
Could you suggest a Coast of Maine product for use in your soil base recipe? I’ve seen Stonington Blend available in my area, but that looks more like a pre-amended potting soil than a more basic compost. This is my first go at an organic outdoor grow, and I’d like to try to stick as close to your recipe as I can, because all of your plants look just fantastic! Thanks for sharing!
Aaron (Mr. DeannaCat)
Hi Bryan, I would use their lobster compost or their manure blend compost, whatever is more accessible to you should work out great, hope that helps and have fun growing!
Hello, I made your soil recipe last year and it worked GREAT! My question is about this year. I kept the soil alive using your cover crop suggestion, but the 30gln pots went through a very heavy rain 6weeks ago and my concern is nutrient loss from too much water.
What should I amend the soil with to prepare for this year?
Aaron (Mr. DeannaCat)
Hi Doug, so glad to hear the soil worked out so well for you last year. We typically re-amend grow bags with 1/4 to 1/2 cup each of neem meal, kelp meal, crab meal, gypsum, and oyster shell flour if you have all of those amendments on hand. If not, you can use a blended amendment such as this one and either way, just proceed as usual when it comes to feeding the plant throughout the growing season. Hope that helps and have fun growing!
Perfect… Thank you much!!!
Hi, Have you ever started your seeds in a smaller pot? I start a lot of my flowers in 72 cell trays and was wondering if I could use the same size cell for my cannabis seeds? Thanks, Sarah
Aaron (Mr. DeannaCat)
Hi Sarah, yes you can absolutely start your seeds in the smaller cell trays, we just like to use the 4 inch pots for germination so we can leave them in there for a number of weeks (usually 2-3) before we have to pot them up. If you start off with the smaller cell packs, you just have to be prepared to pot them up sooner which isn’t really that big of a deal. Hope that helps and good luck!