Want to grow cannabis from seeds? Read on for everything you need! Includes info on your genetics, lights, nutrients, grow tents, soil media, and more! Jack Frost Landscapes & Garden Center blog for updates on sales and products as well as gardening tips and tricks, recipes, crafts, and more! How do I germinate marijuana seeds? Cannabis germination is the process of getting your seeds to sprout, and you know sprouting has occurred when a little white tendril pops out of the seed.
How to Grow Cannabis from Seeds in 7 Steps: The Ultimate Guide to Your Best Cannabis Grow – 2020
Growing cannabis from seeds is easier than you might think. Read on for info on genetics, soil & other grow media, grow tents, lights, nutrients and more!
Before we begin, I’ll be straight with you: All you really need to grow cannabis from seeds is a pot, grow media like soil or coco, seeds, water, plenty of light, and a few nutrients. That’s it. Of course there are other supplies you could use such as a grow tent or high performance LED light, but they’re not always necessary. Cannabis has a long history of wild growth without any help from people. There’s a reason they call it “weed,” and that’s because it grows like one.
But even though you can grow cannabis without any special equipment, there’s an advantage to spending a little money on the right equipment. Industry experts are constantly improving their products which in turn help produce higher cannabis yields and a better flower. So today, as part of our mission to educate and provide valuable information, we’re going to go through each stage of your cannabis grow and highlight some of the equipment that can help you maximize your harvest.
Do you want to learn how to grow cannabis? Check out Growers Network University!
1. Cannabis Genetics
Genetics is just a fancy word for your seeds, and that’s what you need if you want to grow cannabis from seeds! The term can also refer to cannabis clones, but for the beginning grower, seeds are much easier to source. If you are interested in starting from clone stock, you can generally purchase them from a qualified local grower, assuming there are no laws against clone sales in your jurisdiction.
But which Cannabis seeds to buy? That depends on your grow style and personal preference. You’re going to choose an Indica, Sativa, or hybrid or course, but do you want regular seeds, feminized seeds, autoflowering seeds, or some combination? With regular seeds you’ll have to remove any males before they mature and pollinate your females or you’ll end up with seedy, low-quality buds. Additionally, cannabis grown from regular seeds will only flower in response to a change in the photoperiod (how many hours of light they are exposed to) so farming these types of seeds requires a bit more care and attention than autoflowering strains (which produce buds when they are old enough, not in response to the light) or feminized seeds which eliminate the need to monitor for males. If you’re looking for the simplest type of seed, you can go with autoflowering, feminized seeds.
Note: See our cannabis seed FAQ section below the article.
2. Cannabis Germination
Germinating refers to sprouting your cannabis seeds prior to planting. This isn’t always necessary when growing cannabis from seeds, but it WILL improve your chances of germination. The easiest way to do this is to fold your seeds inside of a moist paper towel and wait for a few days, making sure your paper towel remains moist. In this time you should see your seed “pop” as the tap root emerges. Now you’re ready for planting.
If you want a more controlled germination of your cannabis seeds, there are mini-greenhouses available with starter pods which allow your seeds to begin rooting prior to transplanting them into your grow media and offers an overall safer transition from germination to pot.
You can have a look at germination domes here.
3. Grow Media, Grow Tents, & containers
More than likely, you’ll be growing indoors in a grow tent and in soil. There are a variety of media types available including soil, peet, and coco. We recommend soil for the beginner, but whichever you choose it’s important not to skimp on the media. Spending a little extra money on your media will pay off in terms of cannabis quality and help you avoid problems such as pests, unbalanced pH, and poor nutrient delivery. You can see a few recommended soil and other media products here.
You’ll probably also need a pot. The pot you choose should be at least one-gallon and allow excess water to drain off. Once you’ve added the media to your pot and have your seeds, you’re ready to plant. Just insert your finger into the soil to create a ½ inch to 1 inch divot and place your popped seed inside. Cover and water appropriately. We recommend fabric pots which are reusable, lightweight, and drain very well.
The last thing to consider when planting your germinated seeds is where are you going to grow them? Are you growing in a closet? Do you have a dedicated space somewhere in your home? If not, a grow tent is an excellent option for creating a highly controlled growing environment. Grow tents are easy to assemble and their reflective interior maximize light efficiency. There are even kits that will provide everything you need including a fan to generate necessary air flow and a filter that will help keep the smell of your plants from wafting from your grow tent into your personal space. Even if you don’t mind the smell, your neighbors might! You can check out this grow tent configurator which will guide you through the best grow tent set up depending on the space you have available and the number of plants you plant to grow. You can check out our recommended soil media here. Need a pot? Check these out.
4. Cannabis Grow Lights and the Vegetative Phase
The vegetative stage is where your plants bulk up and develop the frame necessary to support the eventual flowers. As mentioned in the genetics portion of this guide, your seed choice will influence the amount of care and attention you’ll need to provide. If you choose regular seeds, the vegetative stage of cannabis growth will require an 18-6 light cycle (18 hours on and 6 hours off). The size of your grow will determine your light requirements and there are many choices. I tend to recommend LED lighting because they’re energy efficient and produce less heat than other types of grow lights, which will help keep overall temperatures down in your grow. Check out a few LED recommendations for your cannabis grow here. Keep in mind the size of the light if you’re using a grow tent to assure it will fit.
Fluence is a great LED brand, but far from your only option.
The vegetative phase is also where you begin monitoring the sex of your plants and then remove and destroy the males as soon as you identify them. If you have access to female clones, this step isn’t necessary, but it will be if you grow cannabis from seeds. You can check out our guide to sexing your plants here. Again, this is a step you need to take when growing from regular seeds. If you use feminized seeds you can be nearly 100% certain that all of your plants are female (1 in 1000 feminized seeds may turn out male).
Since the vegetative stage of growth is where your plant will bulk up and develop its framework, you’ll want to make sure you use some quality nutrients to ensure your cannabis grows strong and healthy. Click here for our recommendations.
A nutrient bundle is a great way to save money
Last but not least, an important consideration during the vegetative stage is pest control. It’s important that you monitor for pests and diseases during the duration of your grow to deal with any problems before they reach crisis level and threaten your crop. Fortunately, close monitoring and cleanliness will help you avoid most of these problems, but should you encounter pests or disease, there are a number of great, organic products that can take care of nearly any problem. And don’t worry, we recommend only products suitable for treating consumable plants. Check them out here.
5. Flowering & Nutrients
The flowering stage is when your cannabis plants will develop their buds. Again, if you choose to grow from “regular” seeds, you’ll change up the light cycle from the 18-6 you used in veg to a 12-12 cycle (12 hours on and 12 hours off up until harvest); autoflowering varieties won’t require this change as again, they flower when they are mature enough.
During this stage you are going to want to continue monitoring for pests and also add a “bloom formula” nutrients to help make big healthy buds. See our recommendations for your cannabis grow here.
6. Cannabis Harvest
A week or so before harvest you’re going to want to “flush” your media. This simply means that you stop feeding your plant nutrients and give only water. This allows your cannabis to use up all the available nutrients remaining in the soil so they won’t end up in your buds. Also, you can expect a degree of leaf yellowing during this final week as your plant converts its available resources into energy for continued bud development.
You can see our full article on when to harvest your buds here, but generally, you can determine when your buds are ready for harvest by examining the trichomes. You can use microscope to get a close up look at the trichomes. Clear trichomes generally mean it’s too early to harvest and your buds won’t be as potent. Milky white-amber trichomes means you are ready to harvest and can expect decent buds. If you wait longer, until the trichomes are completely amber in color, you’ll get a stronger psychoactive effect as CBD levels decline.
Harvesting generally requires scissors or gardening shears to remove your colas (bud sites) from your cannabis plants. Be gentle as to not disturb the potent trichomes.
7. Drying and Curing
Before we go into drying and curing, we should quickly revisit trimming. Trimming can be done before drying (wet trimming) or after drying (dry trimming). Either method is fine and will depend on your preference. The goal when trimming isn’t only to make your buds pretty by removing any fan leaves (which it definitely does) but also to collect the “sugar leaves” that surround your buds. Don’t get rid of these sugar leaves. They’re great for extracts, hash making, and in a pinch you can even smoke them, though smoking them will be a bit harsh.
With proper temperature and humidity control, you’ll be able to dry your cannabis in the same space you grew it. Most growers I’ve spoken with dry for a minimum of one week and often up to 10-14 days. There are a number of drying racks available that will allow you to spread out your buds for even drying. If you choose to dry trim, you’ll do this after drying but before curing.
Curing is a specialized drying process that comes after the initial drying and trimming. The goal is to cure the buds much like you would with homegrown herbs. You want a dark space with low humidity. You can cure in a glass jar, plastic tub, or a specially designed c-vault. You’re going to want to “burp” your container daily to remove any moisture remaining in your buds, and this is accomplished by simply opening the container and closing it again. The curing process can last anywhere from a few days to a couple weeks. Check out a few helpful products here.
A hanging mesh drying rack is only one option for your drying needs.
The CVault is designed to provide complete darkness and airtight bud curing.
So are you ready to grow cannabis from seeds? Hopefully we provided some good tips for media, lighting, and grow tents to get you started. We’d love to hear from you regarding your grow so please leave a comment in the survey below or click one of the “Join Now” buttons at the top and bottom of this article to get into our private, vetted, professional forum. And don’t forget to check out Growers Network University! See you there and happy growing!
A few questions about mail order cannabis seeds
Where can I buy cannabis seeds safely?
There are a number of good seed vendors out there. Our recommendations are established companies with great customer reviews so you know you’re purchasing quality cannabis seeds.
Is it safe to order cannabis seeds through the mail?
People always wonder about the legal risk of purchasing cannabis seeds through the mail. Legitimate seed vendors (including those we recommend) ship discreetly to most locations. Seeds can be stopped by customs, but this doesn’t happen often. You also want to make sure that wherever you decide to purchase your seeds will also ship to your country. This information should be transparent and available on the vendor’s website.
Before You Purchase
Questions you should ask before purchasing Cannabis seeds online
- Do you recognize the name of the cannabis seed company name? Branding goes a long way and a recognized, established brand is something to consider when purchasing Cannabis seeds online.
- What are customers saying in their reviews? Did they receive their seeds? Were they high quality?
Researching these questions will increase your chances of being happy with your Cannabis seed purchase.
- Do you know anybody who has used them as their Cannabis seed supplier?
Word of mouth recommendations are very powerful in the cannabis community. Someone else’s first hand experience can be helpful if you aren’t sure about which brand of Cannabis seeds to purchase.
- What’s their return or refund policy?
A good seed shop should at least have generally positive reviews and a well-defined refund or exchange policy.
Beware of cannabis Seed Scams
If you’re contacted via social media to purchase seeds, chances are you’ve been targeted for a scam. We recommend using established cannabis seed vendors such as those linked above.
Stages of Growing Cannabis
Cannabis, weed, marijuana, kush, ganja – whatever you want to call it, it’s now legal to own and grow in the state of Virginia. So what does this mean for those interested in growing it?
Growing Cannabis for the first time can be quite overwhelming. A quick Google search will lead you to hundreds of results with more information than you can ever sift through. There’s so much to learn – lighting, pH, soils, training methods, curing, and so much more. Where does one start?
It’s really easy to fall down the rabbit hole of information online. The sheer amount of information can almost hinder you when you’re first getting started. I think it’s easiest to just get started and learn as you go.
Starting with gaining a general understanding of the stages of growing Cannabis is a great place to begin before you try growing for the first time. It will help you have a decent idea of what to expect along the way.
How long does Cannabis take to grow?
How long Cannabis takes to grow can vary based on the variety of the plant and conditions it is grown in. On average, from seed to harvest, it takes anywhere from 10-32 weeks (about 3-8 months). It’s a quicker process if you start with a clone (rooted cutting) or an autoflower seed. The biggest variability in how long a marijuana plant takes to grow will happen in the vegetative stage—after the seedling phase and before flowering.
Stages of Growing Cannabis
Every plant begins with a seed. Cannabis seeds should be germinated just like any other seed. They can take anywhere between 3-10 days to germinate, although it can happen in as few as 24 hours or as long as 2 weeks. To germinate, you can place the seeds in a damp paper towel, which you should then place in a dark place, such as inside a drawer. Check on them after a few days to see if the primary root, called the radicle, has emerged. This will look like a little white “tail” coming out of the seed. Once germinated, move them to damp soil.
Alternatively, you can place the seeds directly in damp soil to germinate and grow, without having the trouble of moving them. For this method, I would recommend a seed starting mix. These are usually lighter and fluffier than traditional potting soil, which gives your fragile germinating seeds a start on the right foot. We carry Coast of Maine Sprout Island Blend Organic Seed Starter Mix. It has additional perlite that aerates the soil and helps prevent damping off. It also has mycorrhizae, worm castings, lobster meal, hen manure, and kelp to get your plants off to a healthy start.
2. Seedling Stage
Once your seed has germinated, it’s now time to move the germinated seed from its paper towel to a growing medium. If you started them in a seed starting mix, you will want to move them from the seed tray to a larger pot with a high-quality potting mix, such as the Coast of Maine Stonington Blend Grower’s Mix. This is a super soil, that works especially well for growing Cannabis. It contains mycorrhizae, kelp, alfalfa meal, fish bone meal, worm castings, perlite, manure, peat, coir, and lobster compost that feed your plant throughout the growing cycle, with no need to use additional nutrients.
Plants are considered seedlings for about 2-3 weeks after germination. During this time, the plant should be moved to a spot with direct sun, if growing outdoors. If growing indoors, set your grow lights to run for 16 hours a day.
3. Vegetative Stage
After the seedling stage, Cannabis plants move to a vegetative stage. This is the time when the plant focuses on leaf production. It will not produce flowers at all during this stage, as the plant needs to grow plenty of leaves to take up enough photons (sunlight) to create the necessary energy to produce large flowers. The vegetative stage can last anywhere from 3 to 16 weeks, depending on the variety.
During this stage, indoor plants need 16-18 hours of light per day, and outdoor plants need at least 6 hours of direct sunlight (“full sun”), plus several hours of indirect sunlight. They will also need plenty of Nitrogen during this point, as Nitrogen is the nutrient that promotes healthy leaf growth.
The flowering stage is the last stage of the Cannabis plant life cycle. This is the time when your plant will stop putting as much energy into leaf growth and will instead focus that energy on creating the flowers (buds), which are used for medicinal and recreational purposes.
Stages of Flowering – Source: Katie Plummer
Cannabis is triggered to flower when the hours of light it receives are reduced. If you’re growing outdoors, you’re at the whim of the seasons and will have to wait until the sun starts to go down in fall for it to flower and then harvest. If you’re growing indoors, you get to play mother nature and can force your plant to flower at any point. When you’re ready for plants to start the flowering stage, change your lights to a 12/12 cycle ( 12 hours with the light on and 12 hours with it off ). You will see signs of flowering in 1-3 weeks . On average plants will be ready to harvest after 8-11 weeks of flowering.
Your plant will be ready to be harvested once flowers are compact and the pistils turn orange/brown. These pistils look like “hairs” coming out of the flowers.
To dry your Cannabis, hang sections of the plant upside down in a dark, cool space, such as a closet. You want to aim for 55-65% humidity and 60-70°F in the spot that you’re drying your plants in. Prolonged periods of light, friction from handling, and humidity/dampness can degrade resin glands, so you will want to avoid all of these.
During the drying process, plants lose roughly 75% of water weight, which increases the cannabinoid to weight ratio. It also helps equalize moisture content, preserve cannabinoids, and shed chlorophyll.
Cannabis is ready to trim once the stem snaps when bent, typically after 3-7 days of drying.
After your plant has dried, it’s time to trim! Trimming makes your fingers very sticky, so wear gloves if this is something you want to avoid. Simply trim off the larger leaves and stems. You can leave smaller sugar leaves if you’d like, as these still contain a good amount of cannabinoids and terpenes that provide the medicinal properties of Cannabis. It’s all personal preference of exactly how much you trim off. And you can save all the trimmings to make edibles, tinctures, salves, and more.
Curing is an essential part and the last stage in growing Cannabis. It helps the buds achieve full aroma. Curing is as simple as placing your freshly trimmed buds in a glass jar with a lid, like a mason jar. You’ll then want to place the jar in a cool, dark place, such as inside a drawer or in a cabinet.
During the first week of curing, you will want to “burp” your jars. This means you should open the containers once or twice a day for a couple minutes to allows moisture to escape and replenish the oxygen inside the container. After the first week, you only need to burp containers once every few days.
You should allow buds to cure for at least 2 weeks, but some people choose to cure for as long as 6 months. This helps stop the loss of moisture and to preserve flavors and aromas.
How do I germinate marijuana seeds?
Cannabis germination is the process of getting your seeds to sprout, and you know sprouting has occurred when a little white tendril pops out of the seed.
The little white tendril that emerges from a cannabis seed during germination is your plant’s first root, known as a “taproot.” All other roots made by your cannabis plant in its lifetime will sprout from the taproot.
The taproot – and maybe a few tiny early offshoots of the taproot – will get longer and longer, pushing the seed up, and after the shell breaks through the surface of your growing medium, the first leaves (these first round leaves are known as “cotyledons”) will emerge from inside the cannabis seed.
The cotyledons were already created as part of the plant embryo in the seed itself, so the cannabis seedling doesn’t have to grow them. In fact, the emerging first leaves are what break apart the shell after it’s cracked open by the taproot, as pictured here.
The next set of leaves after the cotyledons are your plants first “true” leaves and will have jagged edges (serrations). At least, they are the first leaves that your seedling cannabis plant has grown all on its own, unlike the cotyledons which were already formed in the seed.
Cannabis seeds can be expensive, don’t waste your seeds with bad germination methods!
(Wait, where can I get cannabis seeds?)
What Do Marijuana Seeds Need to Germinate?
Marijuana seeds need the following to get the best germination rates:
- Moisture – Keep things moist but not soaking (you can soak hard seeds for up to 24-32 hours, but do not leave seeds soaking in water for longer than that).
- Peace – Seeds need to be left alone while you’re waiting for the taproot to show up.
- Warmth – Keep things warm to get the best germination rates, but not too hot! Think springtime. Seeds can definitely germinate in cooler temps, but germination tends to take longer when it’s cool.
- Gentle – Be careful when checking seeds, and treat them gently when you have to move them. Avoid touching their white root if possible; the taproot is very fragile and easily snaps off!
- Plant Root Down – When planting germinated seeds, point the white root downwards into the growing medium to prevent the seedling from having to reorient itself.
- Plant Knuckle Deep – When planting germinated seeds, they don’t have to be placed too far under in the growing medium, about a half inch to an inch (1.3 cm – 2.5 cm) down from the surface of the medium should be enough.
When germinating cannabis seeds, think springtime conditions. In the wild, your cannabis seeds would germinate in the spring so they can be ready to take full advantage of long summer days!
Never let your young sprouted seeds dry up!
The main signal that tells a marijuana seed to start sprouting is the presence of moisture and heat. The combination of warm and wet (aka spring conditions) “tells” the seed to start burrowing their main root (called a taproot) through their shell.
If a seed’s root breaks through the shell and the water around has dried up, your seedling will die. Plain and simple.
Seedlings are fragile at first. Once sprouted, the roots need to stay constantly moist to stay happy and healthy. It’s important to make sure the seeds have access to water the entire time during germination, no matter which cannabis germination method you end up using.
Keep things warm!
Seeds germinate best in warmer temperatures and young marijuana seedlings do better with higher relative humidity in the air. When seedlings are young, they grow faster and healthier when they can absorb moisture from the air through their leaves while their roots are still developing. Dry air won’t kill your seedlings, but it doesn’t make things better. Again, think springtime conditions!
You can use an incandescent bulb (or two) placed over the marijuana seed germination area to help keep things warm. Incandescent bulbs are the opposite of what a grower typically wants: they can’t be used as grow lights, but they’re great at generating heat. Some people will also place a heating pad (the kind you get from a garden store for seedlings) underneath seeds to help aid germination.
Basically, you want to make sure any seeds or sprouts are kept warm and moist at all times, that their roots are unexposed to light, and that they get planted right away.
There are several different methods to germinate your cannabis seeds, and in this article we’ll go through some easy techniques that have proven to be effective.
How do I know if my seeds are good?
Assume all dark seeds are viable, even if seeds can be crushed
Generally, pale-green or white seeds will not germinate, but most dark seeds will germinate when given good conditions.
I used to believe that marijuana seeds were only “good” if they were extremely hard and very dark. One of the first tests I heard to check new cannabis seeds for viability was to try to crush them between my fingers. If the seeds could be crushed, they weren’t good, or so I was told. This has proven to be absolutely terrible advice!
Some of the best plants I have ever grown have emerged from seeds which were flimsy and could be crushed between my fingers. As long as you provide great marijuana germination conditions (as explained above), I’ve found that a lot of seemingly “weak” seeds germinate and produce amazingly hardy plants and great buds.
I do not believe the health of the plant is directly tied to the apparent “health” of the seed. If the seed germinates, it’s a good seed!
Here’s a picture showing several healthy and viable cannabis seeds
Remember! Most of the medical strains of marijuana we grow today (learn how to get seeds) have been bred over many years to produce plants that are easy to grow and which produce potent, medicinal buds. However, these strains have not been selected for the toughness of the seeds they produce since that isn’t important to us as growers. Just remember…
As long as a seed germinates, it’s a good seed!
Germination Method 1: Starter Cubes & Seedling Plugs (Recommended)
One of the best cannabis germination methods is to use specifically-made starter cubes and seedling plugs. These plugs make cannabis germination easy. You simply place the seed in the cube or plug, add water as directed, and seedlings automatically get the perfect conditions for germination.
Each cube or plug already has a hole specifically for you to place your seed. Just stick your seed into the precut hole and pinch the top closed a bit with your fingers. Don’t worry, you can’t mess this part up As long as the seed makes it in there, you should be good.
This is one of the easiest germination methods and doesn’t leave a lot of room for error. Cannabis seeds and clones can be expensive, and sometimes we have genetics we just can’t afford to lose. When that’s the case, germinate your cannabis with one of the following recommended options to ensure as close to 100% germination rate as possible.
Which Starter Cubes Work Best for Germinating Cannabis?
Rapid Rooters (Highly Recommended For All Setups)
Rapid Rooters are easy to work with – you just stick your cannabis seed in the Rapid Rooter (pointy side down), keep your seed warm and slightly moist, and let the Rapid Rooter do its magic.
Sprouts emerge and roots appear in just a few days.
Rapid Rooter starter cubes are suitable for all growing methods, including hydroponics, coco coir and soil. They work for every setup and come from General Hydroponics, a trusted company (the same one used by NASA) which is known for the quality and consistency of its products.
I highly recommend using Rapid Rooters over any other starter plugs. They are less prone to problems and work great with any growing medium (including hydroponic systems).
Pros of Rapid Rooters
- Easy to Use – You Can’t Really Mess Up
- No Prep or Setup – Open the Package and Go
- Some of the Best Germination Rates of Any Method
Cons of Rapid Rooters
- Can only get 50+ at a time (General Hydroponics currently does not offer fewer plugs per package)
- After opening the package, you only have a week or two before they dry out, so if you’re only germinating one or two seeds, you’ll end up having to throw many of the Rapid Rooters away.
There are a few different options for Rapid Rooters, which can be confusing if you’re not sure what you want. The 3 different options for Rapid Rooters are listed here…
Bag of Rapid Rooters
These are round on bottom instead of being a cube, which means they cannot stand up on their own. These are best suited to a hydroponic setup where the Rapid Rooter will be placed directly in the final destination. In our hydroponic setups, we’ve had near 100% germination rates with Rapid Rooters, better than any other seedling cube we’ve tried.
- Round on bottom (won’t stand up by themselves without support) unless you squish the bottom so it’s flat like this grower did (pic)
- Great for starting with Rapid Rooter directly in final destination (hydro, soil, coco coir, etc)
- Get 50 Rapid Rooters at a time
Rapid Rooters Mat
This type of Rapid Rooters comes in a mat of (usually 98) Rapid Rooters. All the individual Rapid Rooters are sectioned off and have a hole for the seed, but they must be cut or pulled away from the complete mat. Unlike the type of Rapid Rooters that comes in a bag, these ones are made into cubes and are flat on the bottom so they can stand alone. This makes them good for germinating in a shallow pool of water where the cubes need to be able to stand up on their own.
- Easily break cubes off the mat (already sectioned off with pre-cut holes)
- Already shaped like cubes with flat bottoms, so they easily stand up by themselves
- Good for seamlessly transplanting your seedlings somewhere else
- Get 98 Rapid Rooters at a time
Rapid Rooters Tray
The Rapid Rooters tray is perfect for seeds or clones. Allow your young plants to sit in the tray with water until their roots are well formed and ready to be transplanted to your final destination. The standard size tray fits most humidity domes. You can refill the tray with Rapid Rooters from the bag or mat.
As you can see in the pictures below, the Rapid Rooter Tray comes packaged up. Once you open the package, you will see 50 Rapid Rooters already set in the tray. The resting place for each Rapid Rooter has a hole on the bottom so water within the tray is wicked up. The top part comes apart from the bottom.
Just add you seeds and pour some water into the tray – the Rapid Rooters will do everything else for you.
- Perfect for cloning or starting seeds with a humidity dome (standard 10-inch by 20-inch dome like this one – 7-inch height recommended for cannabis seeds or clones)
- Easy to transplant to new destination
- Just add water and seeds, that’s it!
- Whole tray can be refilled with any type of Rapid Rooters (from bag or mat)
- Comes with 50 Rapid Rooters, ready to go
Rockwool Cubes (Not Recommended)
It’s often hydroponic cannabis growers who use Rockwool cubes since these can be safely placed in hydroponic setups, hold a lot of moisture, and are resistant to mold. Rockwool is cheap and easy to find. It comes in convenient cubes. But it does have some major drawbacks…
Pros of Rockwool
- Cheap & Easy to Find
- Inert Medium (useful for hydroponic growers)
Cons of Rockwool
- Bad for the environment (unnatural material that does not break down)
- Bad for your health (especially your lungs) – wear gloves and cover your mouth/eyes when handling Rockwool
- Has a pH that is too high for cannabis, so it must be thoroughly rinsed and treated
- Poor cloning and germination rates
- Difficult for new growers
Rockwool cubes are bad for the environment
Rockwool is not a natural material – it’s made by heating rock and chalk to 3,000°F and air is blown through the mixture to create thin fibers of rocky material
It does not break down naturally and therefore after Rockwool is created, it will remain in that form basically forever, filling up landfills without breaking down for thousands of years.
Rockwool cubes can be bad for your health
Rockwool is dusty and needs to be rinsed thoroughly before use. Little pieces of Rockwool and dust can easily get in your eyes, skin and mouth. Small strands or fibers can get lodged in your lungs if you breathe in Rockwool dust, and it’s unknown if these fibers can ever get out again.
Protect yourself! Always use a mask, goggles and gloves when working with Rockwool.
Rockwool cubes have a high pH until they’re treated
New Rockwool cubes have a high pH – too high for healthy cannabis seed germination. Therefore it’s important to thoroughly rinse Rockwool cubes in pHed water, then let them soak in pHed water overnight before use. Since Rockwool holds onto a lot of water, after soaking they should be given a few days to dry out before planting seeds or making clones.
Rockwool cubes do not get great germination rates
Rockwool can be difficult to germinate marijuana seeds in, so I recommend most beginner growers sprout their seeds using another method like Rapid Rooters (mentioned above) which can also be used in hydroponic applications but are less prone to germination problems.
Many growers have placed seeds in Rockwool cubes, only to wait for weeks and never see seedlings appear.
Some growers seem to have no problems, yet many other growers suffer through very poor germination rates. Some seed companies will not honor seed germination guarantees if the grower uses Rockwool because it is notoriously bad for germination.
If you do use Rockwool, it’s recommended you germinate your seeds using another method like the paper towel method, then transplant your seeds to the Rockwool cubes after roots have already appeared.
Even when following all the best practices, we just have not gotten great germination rates with Rockwool cubes, and it’s common for new seedlings not to make it. When we were using Rockwool (before we switched to Rapid Rooters), we usually lost at least 1 seed out of a batch of 6 or 8.
We also had trouble rooting clones in Rockwool. Rockwool cubes just don’t hold enough air to get plenty of oxygen to the roots, and they tend to hold onto a lot of water and get waterlogged easily. Since Rockwool can hold a lot of water, it’s prone to “drowning” seeds
I highly recommend using Rapid Rooters instead for your hydroponic application (or any grow setup), as they are much more user-friendly and tend to get far better germination rates.
Jiffy Pellets (Recommended for Soil or Coco Coir)
Jiffy Pellets are used in a similar way to Rockwool cubes, though these tend to get much better germination results. Jiffy pellets are not suitable for most hydroponic setups where the roots are grown directly in water, but Jiffy Pellets can be directly transferred into soil or coco coir.
Pros of Jiffy Pellets
- Good Germination Rates for Soil and Coco Coir
- Good for Cloning – read a cannabis cloning tutorial using Jiffy pellets
- Come in dried pellets, so they can be kept for a long time
Cons of Jiffy Pellets
- Not suitable for hydroponic setups
- Must be soaked to expand each pellet before use
How to Use: Soak Jiffy pellets in warm water, which makes the pellets expand in size, as pictured below.
Once the compressed Jiffy pellets have expanded in warm water, gently squeeze excess water from each pellet and you’re ready to go. Treat them the same as Rapid Rooters.
Germination Method 2: Plant marijuana seeds directly in growing medium
Sometimes nature’s way is the easiest way. In nature, marijuana seedlings would sprout in soil, and they would emerge as their taproots start growing down.
As a grower, you can also plant your seeds directly in your final growing medium. This works in all growing mediums, though some can be tougher than others.
One of the biggest benefits of planting your seed directly in the growing medium is you don’t have to worry about shocking your young seedling during transplant. Because your seed is already in its final resting place, your new seedling will immediately start adjusting to the environment. Every time you transplant a sprouted seed, it can cause stress as the young plant needs to readjust its new surroundings.
- Soil – Plant seeds a knuckle deep (0.5-1 inch OR 1.3 cm – 2.5 cm) in moist yet not soaking soil. Use a light or a heating pad to keep things warm. This is one of the easiest marijuana germination methods for beginners.
- Coco Coir or other soilless growing mediums – Plant in a similar way to soil
Germination Method 3: Germination Station
One option for growers is to use a tool which has been specifically designed to provide optimal germination conditions like this germination station with heat mat.
You can make a DIY germination station at home by putting a plastic dome over a plate on a heating pad.
There are benefits to the professionally made germination stations as they work very well and are pretty cheap to buy.
When growers start their cannabis seedlings in a germination station, the seeds are usually germinated in a starter seedling cube.
One of the advantages of starting seeds in starter cubes is your sprouted seeds can easily be transferred right to their next growing medium or container.
I recommend Rapid Rooters as these starter cubes work great for cannabis seeds and can be used in any growing medium including hydroponics, soil, or coco coir. Other starter cubes include Jiffy Peat Pellets, and Rockwool cubes.
Once your seed has sprouted, just make a little hole in your growing medium, and place the entire pellet inside. Make sure growing medium is also moist yet not soaking, like your pellet or cube. The roots will emerge from the bottom of the cube and burrow directly into your growing medium.
Germination Method 4: Soak Marijuana Seeds in Water Overnight
Another method to germinate marijuana seeds is to soak them overnight in slightly warm water, usually done in a glass drinking cup.
This method is especially effective for seeds which have extra hard shells, or seeds which are older (more than a few years old).
The warm overnight soaking can help “wake up” older seeds.
Most viable seeds will start out floating, and then eventually sink to the bottom of your glass after a few hours of soaking.
If soaked in a clear drinking glass, you will see when the little white tap root first breaks through the shell.
Some seeds take longer than others to sprout. Especially older seeds tend to need longer to pierce through their shell. However, if seeds are left soaking too long, and haven’t yet sprouted, they can drown.
Therefore, do not leave seeds soaking in water for more than 24-32 hours.
After 24 hours, I recommend putting any still-ungerminated seeds in a warm, moist place to finish germinating.
Germination Method 5: Paper Towel Method
One way to germinate seeds is to wet a paper towel and then fold your seeds in it, then leave the paper towel in a warm place.
Use cheap paper towels! For some reason, the really cheap paper towels work best because they’re so non-porous. Seeds and their roots lay on top without getting stuck to anything. This is important! The more expensive “cloth-like” paper towels (like Viva brand) aren’t good for germination because the roots actually grow into them instead of laying on top.
If you germinate your seeds in a paper towel, there is the risk of hurting the tap root (the little white root that grows out of your seeds) when moving the sprouted seeds so make sure you are careful when you’re checking to see if the seeds sprouted.
There is also the possibility of having the towel dry out which will kill your new seeds so I recommend putting your paper towel under an upside down bowl or between two paper (or regular) plates.
Check on germinating seeds once every 12 hours or so (don’t disturb them or their roots). You can plant any seeds which have sprouted right away, or leave them for another day or two, to let the others keep up.
How to Plant Your Germinated Cannabis Seeds
After you see that your cannabis seeds have sprouted, you should plant them right away.
You don’t want to touch the little white taproot with your fingers, so either carefully move the seeds, or use tweezers. If you do touch or break the root, the seedling may still survive, but any damage to the root will definitely stunt and slow down growth right in the beginning.
Plant seeds so that the white root faces downward, about a knuckle deep into your growing medium. The top of the seed should be just below the surface of your growing medium.
It can take anywhere from a couple of hours to a couple of days before you see the young seedling emerge from the soil or growing medium. If your marijuana seedling hasn’t sprouted from the soil within 10 days after being placed root-down, it probably isn’t going to make it Even with the best practices and the best seeds, you will occasionally lose a seed. Many times it has nothing to do with you!
First sign of taproots. These are ready to be planted!
Rapid Rooters are nice, but not necessary. You can use them before you transfer your seedlings to their final container. The Rapid Rooter should be cut open lengthwise if you plan on using them for germinated seeds. I use big scissors.
Gently place the germinated seed inside, root down. Place the seed close to the surface so it doesn’t have far to go.
Sometimes you’ll have a taproot that is curved or bent. You don’t want to try to straighten it out! Open the Rapid Rooter you split, and lay the germinated seed down gently. The seed and root will naturally lay on the flattest side. Slowly close the Rapid Rooter, and you’ll see that the bent parts of the root will end up in the “crack” of the Rapid Rooter from where you cut to split it open from the side.
After closing a Rapid Rooter, it’s hard to tell it’s been opened. The texture of Rapid Rooters causes the seeds to stay in place and not “fall down” further into the hole once you’ve got it closed.
Sometimes the shell can get stuck on the seedling, but it will often fall off on its own. If it seems really stuck, you can help the seedling by gently removing it.
Within the first week of germinating seeds, you will notice that some seeds germinate right away and others take a little bit longer. This can be caused by a lot of things, from the age of the seed (old seeds have worse germination rates and tend to take longer) to simple chance. The amount of time does not necessarily have anything to do with how healthy your plant will be in the long run.
Once your seeds are safely planted, you can turn on your grow light. The heat from the lamp improves germination rates, and the light can help your new cannabis seedlings open their first set of leaves. In fact, the first set of leaves will often stay yellow until they get light.
If you will be transplanting your seedlings again, avoid transplanting until they are well established and have a couple of sets of leaves (nodes). Some growers will plant seedlings in a growing medium in a solo cup or peat pot, so they can just cut away the cup for easy transplanting.
When you move seedlings around a lot, it stresses them out and potentially stunts their growth. Too much stress can even kill them. So try to plan from the beginning so that you move your seedlings around as little as possible. once they get bigger, they are a lot more hardy and can stand a lot more stress and movement.
Here are some pictures to give you an idea of the timeline to expect
Sprouted seeds planted in Hydrofarm pellets and placed on soil
If you want, you can put bottles on top to help retain extra humidity (like a cheap humidity dome).
It’s a steady 85 degrees F in there, no idea about the humidity in the bottles.
Marijuana seedlings under T5 Grow Light
Day 7 from seed
Your Cannabis Seedling’s First Few Weeks
During the first few weeks of a young marijuana plant’s life, you have to be careful.
Marijuana seedlings, especially seeds from some of the most potent strains, tend to be a bit delicate.
Seedlings definitely won’t be able to withstand full-strength grow lights or nutrients. They need to have a moist environment, but also can easily be drowned or overwatered.
If you’re planting in soil, start with a balanced potting soil that doesn’t contain extra nutrients. I recommend Happy Frog potting soil mix for young cannabis seedlings, but any plain potting mix from your local garden store will do. Never use Miracle-Gro soil or any soil that has “time-released” nutrients already mixed in. After your plants have grown a few sets of leaves, you can transfer them to a stronger potting mix that contains higher levels of nutrients like Fox Farms Ocean Forest soil, or you can start supplementing with cannabis soil nutrients. Don’t want to use nutrients? Learn how to mix up your own super soil so it has all the nutrients your cannabis plants will need!
If you’re planting in coco coir, a soilless medium, or hydroponics, only add cannabis nutrients at seedling strength, or 1/4 the regular strength, until your plants have grown a few sets of leaves. Then you can slowly start working your way up to full strength nutrient levels.
With young marijuana seedlings, less is more.
You’re trying to give young plants a very small dose of nutrients at first. However, even with young marijuana seedlings, the pH of your water and growing medium is important. Some growers get lucky and happen to have water with the right pH, but if you’re noticing deficiencies and problems with your seedlings, definitely take the time to understand about marijuana root pH and how it affects the plant’s overall health.
If you plan on eventually putting your marijuana seedlings under high intensity grow lights (such as HPS or MH grow lights), you may want to start them out with less intense fluorescent grow lights or compact fluorescent bulbs (CFLs). Or just keep your high intensity grow lights several feet away at first, and slowly move lights closer as your seedlings gets older
CFL bulbs (twisty/spiral bulbs as pictured to the right) are a great source of light for young marijuana seedlings
- CFLs provide the right types of light for seedlings
- CFLs are extremely cheap to buy
- CFLs are easy on your electric bill
- CFLs can be found almost anywhere, at your local hardware store, supermart, grocery store, or online
Keep CFLs or fluorescent lights about 6 inches away from your seedlings. Place your hand where the leaves are to make sure it doesn’t feel too hot. If it’s hot for your after 10 seconds, it’s too hot for your plants.
Once your seedlings have developed their first two sets of leaves, then you can move these lights as close as 2 inches away as long as the lights aren’t too hot.
Remember: If grow lights feels too hot to your hand after 10 seconds, they’re too hot for your marijuana seedlings
Make sure to keep a close eye on your seedlings to ensure they don’t grow too close to the grow lights and burn themselves. Seedlings can grow fast, and many growers have been surprised to find plants have actually grown into the light overnight.
If new seedlings are showing signs of stress, try moving the lights further away and see if that helps.
Once marijuana seedlings are about fourteen days old, they’re ready to start being treated as if they’re in the vegetative stage.
This Timeline Will Help Show You What to Expect
Two round cotyledon leaves, then two “real” (serrated) single-finger cannabis leaves
Next, the single-finger leaves expand, and the next set is usually 3-finger leaves
Next, the cannabis plant will start making 5-finger leaves
Finally, most cannabis plants stop at 7-finger leaves
If you look closely at the above plant, you can see that some of the newer leaves on this plant actually have 9 fingers. It is normal for there to be some variation between leaves – some plants will grow leaves with 11 or even 13 fingers. But the above guide will give you a general idea of what to expect.
Once your cannabis seedling is about fourteen days old, it’s ready to start being treated as if in the vegetative stage.
Make sure you learn about plant training techniques to make the most of your time in the vegetative stage!
Wait! My seed is growing upside down with the roots up; what do I do?
As long as the roots of a cannabis seedling are able to grow down, they will. Roots never grow upward on their own. Seedlings can sense the difference between up and down. Roots always try to grow down. Roots never grow upwards.
So how come sometimes it looks like a cannabis plant is growing with its roots pointing up?
When the seed end is still bent down, all you see is a U-shaped stem/root
Cannabis seeds can look a bit different when germinating. When in doubt, always wait a few days to see if leaves appear before you try to interfere.
Sometimes the stem of a brand new cannabis seedling can look like the roots growing out the top. But if you wait and watch, you’ll see that it’s all part of the plan. Hope these pics help someone!
Sometimes you’ll see what appears to be roots emerging from your cannabis seed, but this is actually the stem. The stem pushes the seed and leaves up, and the main taproot is currently burrowing down to support the seedling
As the seedling emerges you’ll be able to see the leaves (sometimes it will still have the seed stuck on the first leaves, like in the picture above).
The cotyledons (first, round leaves) unfurl, and then the regular cannabis leaves between to grow. Here’s another view of that same seedling from above. Even though it may have looked a bit weird at first, this seedling is completely normal and will grow just fine from now on.
What Size Pot Should I Use?
When growing cannabis plants in a container, you have to choose the size of your pot.
A general guide is to have about 2 gallons per 12″ of height. This isn’t perfect since plants often grow differently, but this is a good rule of thumb.
When in doubt, get a bigger final container size as opposed to a smaller one. Plants that get rootbound from being in a too-small container will grow more slowly and be prone to problems. It’s not good to transfer plants during the flowering/budding stage, so you want to have your cannabis plants in their final container at least 2 weeks before the beginning of flowering/budding. How do I get my cannabis plants to start flowering?
Final Container for Desired Plant Size – General guide
12″ ~ 2-3 gallon container
24″ ~ 3-5 gallon container
36″ ~ 5-7 gallon container
48″ ~ 6-10 gallon container
60″ ~ 8-10+ gallon container
But what size pot should you use for your seedlings?
For fastest growth rates, it’s better to plant young seedlings or clones in a very small container, like a disposable plastic solo cup.
For new seedlings and clones, use a small container if possible
The reason you want to start with a small container is that your plant’s young roots thrive on oxygen. Cannabis plant roots “breathe” oxygen, just like we breathe air, and it’s important that young cannabis roots get plenty of oxygen so the plant can grow as fast as possible.
However, young plant roots do not drink much water yet. When you water seedlings or clones in a very big container, they will use up all the oxygen quickly, and the large size of the container will prevent the growing medium from drying out.
A big plant will drink up all the water quickly, but with seedlings, you’re basically waiting for the growing medium to dry out by itself. While you’re waiting for the container to dry out, your cannabis roots are sitting in a wet environment and not getting much oxygen, slowing down their growth rates.
Poke holes in the bottom of your cup so water can drain out easily!
By planting young seeds in a small container with holes in the bottom, the growing medium will dry out much more quickly, allowing you to water more often. The young cannabis will get plenty of oxygen and water.
Alternative to Solo Cup: Start plants in seedling cube
If you don’t want to have to transplant your young plants, you can start them in a seedling plug or cube and wait until you start seeing roots come out the bottom. At that point, they will be ready to be transferred to a larger container.
What happens if I plant seeds or clones in a big container?
Your cannabis seedlings and clones will definitely survive in a bigger container; they just won’t grow as fast for the first few days or weeks because they aren’t getting as much oxygen.
With a bigger container, you will need to wait longer between waterings, and during that time your plant roots will be getting reduced oxygen.
If you’ve planted your young plant in a large container, try to give only a little bit of water at a time (enough to wet the area around the seedling roots) until the plant is growing vigorously. Once the plant has grown a few sets of leaves, you should start watering cannabis normally so that water drains out the bottom.
One of the advantages of starting young plants in a big container is you won’t have to transfer them to bigger containers as they get older.
If you would like to take advantage of faster vegetative growth from transplanting, view the Complete Cannabis Transplant Guide (with pics!)