When it comes to how to germinate marijuana seeds, every gardener knows that you must plant a seed to grow a garden. B
But you say "Mitch, what about clones? They're not seeds."
This is true, but at some point in a young clone's life there was a seed planted to produce its mother. So, it all starts with the seed.
Learn how to germinate marijuana seeds in this comprehensive tutorial from Grow Weed Easy. It covers everything you need to know, and quite possibly things you don't, to insure those expensive, hard to come by, marijuana seeds, are put to good use. So, without further ado:
How to Germinate Marijuana Seeds Introduction
Cannabis seed germination is the process of getting your seeds to sprout.
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. They are the first leaves that your seedling cannabis plant has grown all on its own.
How do I know if I have good cannabis seeds?
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 long as you start with good genetics, Seemingly "weak" seeds can germinate and produce amazingly hardy plants with great buds.
NOTE: Most of the medical strains of marijuana we grow today have been bred over many years to produce plants that are easy to grow and which produce potent, medicinal buds. That's good genetics.
However, these strains have not been selected for the toughness of the seeds they produce since that isn't important to us as growers.
If the seed germinates, it's a good seed!
What Do Marijuana Seeds Need to Germinate?
When germinating cannabis seeds, think springtime conditions.
In the wild, nature would germinate marijuana seeds in the spring so they can be ready to take full advantage of longer summer days.
If you follow the guidelines outlined below, you will see 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). If a seed's root breaks through the shell and the moisture 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.
- Peace and Tranquility - Seeds need to be left alone while you're waiting for the taproot to show up. 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!
- Heat - 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. Some people will also place a heating pad (the kind you get from a garden store for seedlings) underneath seeds to help aid germination. I have also set them behind a TV or on top of fridge, as both generate heat.
- Humidity -- Young marijuana seedlings do better with higher relative humidity in the air. They grow faster and healthier when they can absorb moisture from the air through their leaves while their roots are still developing. If your seedlings are uncovered or the air is dry, try using a spray mister to keep the little ones moist.
- Plant Root Down - After your seed has sprouted and ready to plant, with your finger, push a hole in grow medium 1/2" to 1" deep, point the white root downwards into the growing medium to prevent the seedling from having to reorient itself. cover loosely with grow medium.
How to Germinate Marijuana Seeds 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...
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.
- 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 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.
Pros of Rapid Rooters Mats
- Easily break cubes off the mat (already sectioned off with precut 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
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.
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 your seeds and pour some water into the tray - the Rapid Rooters will do everything else for you.
Pros of the Rapid Rooter Tray
- Perfect for cloning or starting seeds with a vented humidity dome (standard 10-inch by 20-inch dome - 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
Cannabis Seed 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 of Rapid Rooters on a heating pad.
There are benefits to the professionally made germination stations as they work very well and are pretty cheap to buy.
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
Always use a mask, goggles and gloves when working with rockwool.
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.
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 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 or soil.
Pros of Jiffy Pellets
- Good Germination Rates for Soil and Coco Coir
- Good for Cloning
- 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.
How to Germinate Marijuana Seeds Method 2: Plant marijuana seeds directly in growing medium
Sometimes nature's way is the easiest way. In nature, marijuana seedlings sprout from the soil 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 medium - Plant in a similar way to soil.
How to Germinate Marijuana Seeds Method 3: 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, they 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.
How to Germinate Marijuana Seeds Method 4: Paper plate method
This is old school and a very tried and true method.
To germinate seeds, wet a paper towel and then fold your seeds in it, then leave the paper towel in a warm place.
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 plates.
Also, if you move the paper towel to the upper edge of the plate, leaving part of it near the center, you can put a bit of water in the center of the plate. This allows moisture to wick up the paper towel leaving the seeds out of direct contact with the puddle.
If you germinate marijuana seeds in a paper towel, be very careful when moving them to your grow medium. There is the risk of hurting the tap root (the little white root that grows out of your seeds) when moving the sprouted seeds. Make sure you are careful when you're checking to see if the seeds sprouted.
Check on germinating seeds once every 12 hours or so, making sure not to disturb them or their root. Plant any seeds which have sprouted right away.
That's it, we've just sprouted. It's really not hard to grow marijuana. Just plant a seed, water it and watch it grow.