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How do I germinate marijuana seeds?

by Nebula Haze

Marijuana seeds that have just sproutedMarijuana germination is the process of getting your seeds to sprout. The little white shoots emerging from the seeds during germination are your marijuana plant's first roots.

Cannabis seeds can be expensive, don't waste your seeds with bad germination methods!

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Introduction: What Do Marijuana Seeds Need to Germinate?

Marijuana seeds need the following to get the best germination rates:

  • Moisture - keep things moist yet not soaking (you can soak hard seeds for up to 24-32 hours, though do not leave seeds soaking in water for longer than that)

  • Undisturbed - A safe place to sprout where they won't be disturbed - either you plant the seeds directly in the growing medium, or germinate them somewhere else and move them

  • Warmth - Get the best germination rates by keeping germinating marijuana seeds in a warm place, not too hot! Think springtime.

  • Gentle - If you must move sprouted seeds, treat them gently, and avoid touching their roots if possible

  • Plant immediately - If you're not germinating seeds directly in the growing medium, check on seeds regularly so you can plant them right away once they're sprouted white roots

  • Plant seeds with the root down! When planted germinated seeds, make sure the white root is pointed downwards. Seeds planted upside (with roots facing up) down take extra time to reorient themselves and emerge from the growing medium

  • Plant a 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 should be enough

Think springtime conditions when germinating marijuana seeds

For marijuana seed germination, think springtime conditions. In the wild, marijuana seeds germinate in the spring.

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 "tells" the seed to start borrowing 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.

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 germinationg method you use.

Keep things warm!

Seeds germinate best in warmer temperatures and young marijuana seedlings enjoy 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.

You use an incandescent bulb (or two) placed over the marijuana seed germination area to help keep things warm. 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, but I will list some easy techniques that have worked for me.

How do I know if seeds are good?

Assume all dark seeds are viable, even if seeds can be crushed

Healthy marijuana seeds are dark and hard, they cannot be crushed with your fingers Stripes and other dark coloring is normal.Generally 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 marijuana 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 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 "weak" seeds germinate and produce amazing, hardy plants, and great buds.

I do not believe the health of the plant is directly tied to the apparant "health" of the seed. If the seed germinates, it's a good seed!

Remember! 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. These strains have not been selected for hardy seeds.

As long as a seed germinates, it's a good seed!

Germination Method 1: Paper Plate 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.

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 plates.

Paper Towel Method - Germinate Marijuana Seeds Demonstration
The image above is a section of the Marijuana Stealth Grower's Cheat Sheet.

Check on germinating seeds once every 12 hours or so (make sure not to disturb them or their roots) and plant any seeds which have sprouted right away.

Jump down to section on how to plant your germinated seeds

Germination Method 2: Soak Marijuana Seeds in Water Overnight

Place seeds in a glass (or in this case shot glass) of plain warm waterAnother 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.

Soaked marijuana seeds sprout new white taproots

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.

How to Plant Your Germinated Marijuana Seeds

After you see that your 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 twissors. 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.

Root down! Plant seeds so that the white root faces downward, about a knuckle deep.

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 died. I'm sorry. Even with the best practices and the best seeds, you will occasionally lose a seed.

Within that 10-day period, you will notice that some seeds germinate right away and others take a little bit longer. The amount of time does not really have anything to do with how healthy your plant will be in the long run. It usually has more to do with the placement of the seed and where its root sprouted.

Avoid letting light tough the roots! Light can be dangerous to young marijuana roots. In fact your seedlings can't even use light until they develop their first set of leaves, called the cotyledons. Until then they are powering themselves based just on the nutrients that were contained in the seed.

Before they get their first leaves, you only want to use your lights as a heating source to maintain a warm environment. The actual light will not help young seedlings grow faster until they've developed their first set of leaves.

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's some pictures to give you and idea of the timeline to expect

Sprouted seeds planted in Hydrofarm pellets and placed on soil

Seeds are starting to sprout

If you want, you can put bottles on top to help retain extra humidity (like a cheap humidity dome).

Ultra cheap humidty dome :)

It's a steady 85 degrees F in there, no idea about the humidity in the bottles.

Seedlings under my T5 Grow Light
Marijuana seedlings under T5 Grow Light

Day 7 from seed - View the full album by im4potato right here:

Day 7 - Marijuana seedlings - Auto Northern Lights strain


Jump down to section on How to Take Care of Marijuana Seedlings - First Few Weeks

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.

Rapid Rooters are available on AmazonWhen growers start their cannabis seedlings in a germination station, the seeds are usually germinated 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, Hydrofarm pellets, and Rockwool cubes (more info in the next section about the different starter 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.

Jump down to section on How to Take Care of Marijuana Seedlings - First Few Weeks

Germination Method 4: 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 causes 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

Stater Cubes

  • Rapid Rooters are available on AmazonRapid Rooters (Recommended) - Easy to work with - you just stick your cannabis seed in the Rapid Rooter, 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. These starter cubes are suitable for hydroponics, coco coir and soil. I highly recommend using Rapid Rooters over other starter plugs as they are less prone to problems, and can be transferred to any growing medium, or even used in complete hydroponic situations.
  • Rockwool Cubes - Advanced! It's often hydroponic growers who use rockwool cubes since these can be safely placed in hydroponic setups, hold a lot of moisture, and are resistant to mold. However, rockwool can be difficult to germinate marijuana seeds in, so I recommend most beginner growers sprout seeds using another method like Rapid Rooters (mentioned above) which can also be used in hydropnic applications but are less prone to germination problems. If you do choose to germinate you cannabis seeds directly in the rockwool cube...
    • Wet the rockwool cubes with warm water on top - don't soak them
    • Tuck seed gently, pointy side down, in moist rockwool cube (there should be a slit or hole where the seed can be placed)
    • Press/pinch the rockwool slightly around the seed to make sure the seed is gently yet firmly held in place.
    • Keep rockwool moist yet not soaking (it is recommended you do not add more water unless the rockwool begins to dry out - rockwool can hold a lot of water and it's prone to "drowning" seeds).
    • Keep things warm! A warm light or seedling heating pad works great.
    • Seedling should emerge in 2-10 days, though occasionally may take longer.
    • Rockwool is notorious for being difficult for marijuana germination. Some growers seem to have no problems, while other growers suffer through very poor germination rates. However, many hydroponic growers will choose to transfer young sprouted seedlings to a rockwool cube, and these directions are there to help those growers. Again, I highly recommend using Rapid Rooters instead for your hydroponic application, as they are much more user-friendly and tend to get better germination rates.
  • Jiffy Pellets - Use in a similar way to rockwool cubes, though these tend to get 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.
  • Hydrofarm Pellets - Use like rockwool or Jiffy Pellets, when soaked, these pellets expand quite a bit!

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.

With young marijuana seedlings, less is more.

Give them just plain water or give them 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 flourescent grow lights or compact florescent bulbs (CFLs).

However, you can put young seedlings under intense lights, just keep them several feet away at first, and slowly move closer as your seedlings gets older.

CFLs can make great grow lights for small, stealthy growsCFL bulbs (twisty/spiral bulbs as pictured to the right) are a great light source 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 flourescent lights about 6 inches away from your plants. 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 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 be start being treated as if they're in the vegetative stage.



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