How to Germinate Marijuana Seeds

Rambo December 31, 2011 47
How to Germinate Marijuana Seeds

Germinating marijuana seeds and caring for marijuana seedlings is one of the easiest steps in growing marijuana. That said, if you do not know what you are doing, it is also an easy step to get wrong. High quality marijuana seeds are not cheap, and ordering them can be risky. So you want your germination rates as high as possible. Here are some of the surefire ways marijuana growers limit environmental stresses and help marijuana seeds grow into healthy, vigorous and hopefully female marijuana plants.

Selecting Marijuana Seeds

Entire books have been written on choosing the type of marijuana strain to grow, but here are some general guidelines for determining the viability of a marijuana seed.

It is not always easy to tell if a marijuana seed will germinate simply by looking at it, but it is not hard to weed out the weak ones. Healthy, viable marijuana seeds should be slightly oblong and shaped like a teardrop with a point at one end. Size varies ,but marijuana seeds are usually about 1/8th of an inch wide and 3/16th of an inch long. Their color is usually brown, often with darker stripes like a brindle dog.  Marijuana seeds that are tiny, soft (immature), greenish, yellow, white, or chipped are not likely to germinate. In the end, there is really only one way to find out: try it and see.

Marijuana Seed Germination

Germinating marijuana seeds requires only the correct amount of water, heat, and air. Nothing more is needed; nor is it even beneficial.

Water – Marijuana seeds require moisture to trigger the hormonal changes that make the germination process possible. Planting your seeds in high quality soil or pH balanced Rockwool and watering regularly to maintain constant moisture will be sufficient for most marijuana seeds to germinate. As water passes through the seed’s shell, dormant hormones stored within the seed are activated. As the water continues to penetrate the shell, the seed will begin to grow and produce a taproot. Constant available moisture is required to continue the seed’s growth into a healthy plant.

Ideally, you should use bottled drinking water for germination. Tap water from a municipal water supply usually works fine, but contains chlorine. Well water can contain high levels of dissolved solids that can hamper early root growth. The chlorine in municipal water is not a major problem, and will dissipate if left exposed to the air.

Here is some further information to answer any questions about water quality and growing marijuana.

Heat – Marijuana seeds can germinate in many temperature conditions, but grow best between 75 and 80 degrees Fahrenheit (23-26 C). Cooler temperatures slow seed germination and promote fungal growth such as fusarium and pythium which can rot the seed and root. Temperatures above 90 degrees can also inhibit germination.

Oxygen – Marijuana seeds require air–specifically oxygen–to germinate. After germination the roots will require air, and the leaves will require CO2. Marijuana is native to primarily arid climates, not jungles and swamps. So if the growing medium is too moist or the seed is soaked for too long, the seed will not receive enough oxygen and will drown. Covering the growing medium with plastic wrap or a seedling dome will trap moisture and limit air exchange; so do not use them. Humidity above 50% promotes the growth of fungus that can damage and kill a marijuana plant while germinating or sprouting.

To promote the highest rates of germination and optimal health you want a warm, moist but not soggy growing medium, and warm circulating air that is under 50% humidity.

Steps 1 – 4 are Entirely Optional

You can use all of these steps, some of them, or none of them at all. Older seeds or seeds that have been allowed to dry out a bit too much are likely to benefit from steps 1 to 4. Marijuana seeds stored correctly that are less than three years old should germinate just fine without these extra steps.  Using these extra steps on newer seeds generally does not create problems and can increase your germination rates, though some advise against them as they increase the potential for human error.  If you skip earlier steps and your seeds do not germinate, you can always go back to earlier steps and try again.

Step 1: Scuffing Marijuana Seeds

By lightly scuffing marijuana seeds with sand, sandpaper, or an emery board you can create tiny scratches in the hull of the seed making it easier for water to penetrate the hull and reach the embryo inside.

Step 2: Soaking Marijuana Seeds

Soaking marijuana seeds in a glass of water can speed up the germination process. Simply place your marijuana seeds in a glass of room temperature bottled drinking water. If the seeds float you can dunk them under a few times with your finger. The seeds should be soaked for 2 to 24 hours, but certainly no longer.

Step 3: Paper Towel Germination

Place a paper towel on a flat but mobile surface like a dinner plate and then place your marijuana seeds on the paper towel. Cover the seeds with a second paper towel and pour bottled water over the top, until the entire paper towel is soaked with water. Tilt the plate to an angle of about 45 degrees so that any extra water will run down and drip off the plate. Place the plate on a heating mat if possible and set the thermostat to 75 F (24 C). Insert the thermostat probe under the paper towels.

As soon as the marijuana seed’s shell has opened and the tap root has begun to show, the seed needs to be planted immediately. This may mean that not all of your seeds get planted at the same time. Do not let the root grow to be several millimeters long before planting, or you drastically increase the likelihood of damaging the root and killing the plant.

Note: In nature, seeds germinate under soil where it is dark; so you do not need lights for germinating. Light can be used to heat a small area if you do not have a heat mat. Take care to  monitor the germination process closely, however, as the light will dry out the paper towels more quickly and damage the root once the seeds open. Also remember heating mats can overheat, and either boil your poor little seeds or cause the paper towels to dry out more quickly. So be sure you use a thermostat for your heating mat.

Step 4: Planting Your Marijuana Seeds

Soil – Fill your small pots with a light and airy potting soil. Gently press the soil down to compact it slightly. Drench the soil with clean water, making sure that all of the soil is uniformly damp but not soggy or waterlogged. Make sure to test the pH of your water and balance it to 6.3 if needed. Create a hole in the soil about half an inch deep with the end of your finger. Gently pick up the marijuana seed with a pair of tweezers and place it taproot (pointed end) down at the bottom of the hole. Gently fill the hole with loose soil to cover the marijuana seed. If you are not sure about what kinds of soil use, here are some helpful directions on the best soil for germinating marijuana seeds.

Note – If you use pots that are too large you will be taking up unnecessary space which will make it more difficult to fit your pots on a heating pad. You will also be bringing a lot more moisture into the room, which means you are wasting money on nutrients each time you water. Also, remember that as this extra water evaporates it will drive up the ambient humidity of the room, increasing the potential for humidity-related problems such as bugs, mildew and mold.

Rockwool – Because Rockwool cubes start with a high pH, you need to adjust the pH down by soaking the Rockwool in lukewarm water with a pH of 5.5.  Let the Rockwool soak for about half an hour and then remove it from the water, letting the extra water drain off.  Next flush the Rockwool with fresh pH 5.5 water, not the water they already soaked in.  After the Rockwool is flushed, create a small hole about half an inch deep with a pencil or screwdriver. Gently pick up the marijuana seed with tweezers and place the seed –tap root (pointed end) down–in the hole. Cover the seed with some loose Rockwool that has also been pH-balanced.

Note – Be sure not to pack the Rockwool around the seed, as it will need to move past or through it. Do not squeeze extra water from the Rockwool, as this can compress it and change the intended air-to-moisture ratio that Rockwool is designed to optimize. Also, remember when growing marijuana in Rockwool it is important to monitor not only the pH of the water you are supplying to the seeds/plants, but also the pH of the runoff water. To keep the Rockwool cubes from sitting in a pool of runoff water, try setting them on a thin layer of perlite.

Step 5: Watering In and Situating Stuff

If you properly drenched the soil or Rockwool before planting, watering in is pretty easy. Just take a few spoonfuls of pH-adjusted water and re-soak the area containing the marijuana seed. This may not be necessary, but will ensure moisture to that area. It is of utmost importance to keep the soil or Rockwool as evenly moist as possible, as dry areas will wick moisture away from the seed. If you allow your growing medium to dry out, it will likely be fatal for your seedlings. Be careful to water very gently. Otherwise, the flow of water can easily uproot a seed before the roots have taken hold. Misting bottles don’t penetrate deeply enough into the soil, so continue to water wit the spoon until the seedling is well-established.

Place the pots or Rockwool cubes in seedling trays, and place the tray on a heat mat with the thermostat set to 75 degrees F (24 C), and the sensor probe either in the soil or the Rockwool. The marijuana seedlings are going to need light as soon as they emerge.  So you might as well turn the lights on from the start. This will give you a few days to observe the effects of the lights on temperature and humidity in the room, and make any needed adjustments. There is no need to throw huge amounts of light at tiny marijuana seedlings. I recommend T5 florescent grow lights with both Blue and Red color spectrum bulbs. T5’s are easy to set up and take down, and much less expensive to buy and operate than the HID grow lights that you will use to grow more mature marijuana plants. They also produce less heat. Make sure the ambient temperature of the room stays in the mid to high 70’s both day and night. Maintain the grow rooms humidity between between 20% and 40% if possible, and certainly no higher then 55%.

Step 6: Caring For Marijuana Seedlings

Within two-five days the seedlings should emerge from the growing medium and, shedding their shells, reveal their ovular embryo leaves (cotyledons). Occasionally, the cotyledons are not strong enough to shed the shell, and may need some very gentle assistance. Try to avoid this if possible, as it requires a jeweler’s precision and can easily go wrong. If you are using T5 Fluorescent Grow Lights, they should be between six and eight inches from the tops of the marijuana seedlings. Set the timer for 18 hours on and six hours off.

For Soil – Once the seedlings have emerged, I recommend waiting a week before adding a 20% strength nutrient to the water.

For Rockwool – You can begin feeding with diluted (20% maximum strength) nutrients as soon as you like. Remember the marijuana seedlings are very fragile at this point. Even a slight miscalculation in nutrient strength can easily kill the seedlings. If you like, you may wait up to a week to begin feeding.

What Not To Do

  • Do not use humidity domes or anything else to cover the pots
  • Do not use heating mats without a thermostat (80 degrees max)
  • Do not use jiffy or peat pellets because the create pH problems
  • Do not use soil that is high in N-P-K, “Hot” or otherwise unsuitable for seedlings
  • Do not fertilize your seedlings in soil for the first week, or use more than 20% strength for seedlings in Rockwool
  • Do not water-log your seeds or seedlings, or allow them to dry out
  • Do not germinate seeds where they will get too cold
  • Do not deprive seedlings of adequate light
  • Do not use water with incorrect pH or other problems
  • Do not foliar feed or spray anything, including water and pesticides, on seedlings
  • Do not handle seeds with bare hands if possible. The oil from your hands can prevent water from soaking in.

Well, this should keep you busy for a week or so. In the meantime, I will be preparing some basic directions to help get you and your marijuana plants through the vegetative period.

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  1. markieaaryn June 5, 2012 at 9:18 am -

    I was having the issues you discussed above. Basically i think what has happened was i provided to much water. I guess i would like to know if they fail to germinate can i fix this. It was advanced seeds low girl and the la musa strain fem of course. Nothing since the 18th of may. help me out

    • Rambo June 5, 2012 at 7:10 pm -

      Sometimes you can get a seed to germinate that has previously failed, but it all depends on why it didn’t sprout. If over watering was your problem… probably not much you can do. You could always try drying the seeds off a bit and then scuffing them. Here is an article to help you out with that

  2. dan March 6, 2013 at 6:49 pm -

    can i germinate seeds in a paper towel an place in cup an put it out side half of the day or window sil? please help i dont have a light

    • Rambo March 25, 2013 at 8:30 pm -

      For germinating seeds even a regular florescent bulb will do. It is not until after the seen is sprouted that you will needs to worry about the quality of the grow light

  3. ntomoma July 2, 2013 at 9:46 am -

    what would happen when i plant the cannibis seed with flower seed together

    • Rambo July 9, 2013 at 1:08 pm -

      What do you expect will happen?

  4. maddy September 27, 2013 at 11:17 pm -

    hey rambo

    i’m a fairly experienced outdoor marijuana grower from india. i used to just stick my seeds in the dirt and watch em grow. purely organic. now, i’ve moved to a different location for a year and i’m dabbling at growing indoors. the catch is, in this city, humidity fluctuates between 75% and 95% depending on the season. my seeds just don’t seem to be germinating, when i take them out of the coco 2 days later, the inside is still white but its just a mushy goo instead of a cotyledon. any advice?

    • Rambo October 2, 2013 at 8:07 pm -

      It sounds like you seeds are to wet and rotting. This could also be some kind of fungus that has contaminated the growing medium. Humidity of 75-90% is going to be a huge problem even if they do sprout. ideally you want to be under 50% or you are going to have lots of pest and fungus problems.

  5. andyi October 8, 2013 at 11:42 pm -

    If the ph of my water was a little high the first time i watered my seedlings will they still germinate?

    • Rambo October 21, 2013 at 12:41 pm -

      a little high is not very specific. But yes they probably will

  6. Grower October 11, 2013 at 10:22 pm -

    How early can you determin a male from female?

    • Rambo October 21, 2013 at 12:55 pm -

      read the article I wrote on this.

  7. Beginna2161 October 27, 2013 at 5:59 am -

    My seed just sprouted this morning . During the day it dropped the shell. It’s in a little pot and the head if the stem moves up and little bit layer will go down again. Is this normal or am I doing something wrong?

    • Rambo October 29, 2013 at 6:55 pm -

      Your question could use some serious editing. I could barely understand your questions, but yes, this is normal,

  8. colin Paterson November 6, 2013 at 1:22 pm -

    Fae Cokeboy. U R A PURE GENTLEMAN RAMBO I took all your advice and I’m a 1st time Grower and I got a 96g from Critical rapido fem seeds Is This a normal from that plant PLEASE Let me know Boddy

  9. medical seeds November 13, 2013 at 7:48 am -

    i just germinated 8 seeds (after 2 days) out of the 10 i got from amsterdam marijuana seeds, 2 are still ungermed, should i wait or should i pot them also although they are nog germed already.

    • Rambo November 19, 2013 at 5:46 pm -

      give it a day or two more.

  10. dorees November 13, 2013 at 4:08 pm -

    My seeds germinated and I have been waiting almost a week now and still nothing has sprouted, I thought I would would have seen some cotyledons but no luck. what do you think is up?

    • Rambo November 19, 2013 at 5:49 pm -

      could be a few things. Planted to deep, not enough water, to much water or possibly something in the soil that ate them or killed them. Could also be to cool.

  11. Tom November 24, 2013 at 7:43 am -

    I have some mature White Widow seeds.
    My seeds are not germinating. They are in their tenth day sitting in rock wool cubes in a cube tray and have not sprouted. I have kept them at about 75 degrees and covered with an inverted tray. I cut open two of the cubes today and the casings have not opened. The seeds still are hard but the cubes a sufficiently wet.

    I have been changing the water in the tray every 48 hours. The water is mixed with B1 according to the
    directions on the bottle. I know some seeds take longer than ten days to germinate. Any suggestions?

  12. LadyGrow November 29, 2013 at 9:46 am -

    This website has been very helpful, everything I’ve tried that you have said, has worked Excellent!! THanks Rambo!!

  13. LadyGrow November 29, 2013 at 9:53 am -

    I have always germinated in a shot glass with a few inches of water, but I think it was always to cold where I kept them, they sprouted in 2 days this time 🙂 thanks to the info about the temp, also I had a question about the soil I just planted them in, we use FF,HF and RO, I read all the info on the bags and went with the RO seeing it had the lite stats, hopefully the pop up out that soil and don’t die? These 3 seeds are the only ones I have of this strain so I’m really hoping the soil isn’t too hot and they make it. Gonna go and look around the site for info on male/female/early detection info!

  14. dan December 9, 2013 at 1:33 pm -

    Hi I have germ some seeds in root it sponge cubes insidea heated proganator in the dark 8 out of ten germed how long do I keep them in the dark and in the proganator for the first to leaves are comin but are yellow coloured I dont no if thats to do with how moist they are

  15. dan December 9, 2013 at 1:40 pm -

    Hi I have germ some seeds in root it sponge cubes insidea heated proganator in the dark 8 out of ten germed how long do I keep them in the dark and in the proganator for the first to leaves are comin but are yellow coloured I dont no if thats to do with how moist they are in

  16. ken hutson December 21, 2013 at 12:55 pm -

    U can get rid of all these steps if u crack the seed Hull open and take the root out and drop it into a fish tank with the fish. U will have a healthy plant in two days. Try it. Fastest germination I have ever accomplished. U will have a six inch plant in three says with second set of leaves. Root lengths will b 4 to 6 inches with major root growth from sides of roots. Fish tanks gave everything I needed.water Ph level and fertilizer. All together it gives a perfect setting. Remember to remove the Hull.

  17. Laki December 27, 2013 at 11:48 pm -

    hi, Rambo, thx a lot for the article
    one question, why u not reccomend to use humidity domes in the first time when seeds not connected with soil or rookwool and cant get water from it’s with small root?

  18. chronicsmoker January 12, 2014 at 5:49 pm -

    Hey Rambo I’m a first time grower in the UK, I have no lights and have no experience growing. I’m looking on growing a few plants indoors & was just wanderin if you could advise me on how to successfully do this. Please help!

  19. saul878 January 27, 2014 at 5:03 am -

    hey Rambo i was looking for some advice. i have had a similar problem to dorees, in that my seeds are yet yo sprout. i have them in rockwool. yet i did not check the ph. Is this a fatal blunder or can it be saved or is it not crucial? thanks for any advice.

  20. gary smith April 22, 2014 at 1:16 pm -

    if I scuff,soak seeds for 4hrs. then plant directly in jiffy organic seedling mix, am I good to go ? I have one question. I plant the seed point down, correct ? Also, these are hybrid seeds.

  21. 1sttimegrower April 23, 2014 at 4:44 am -

    I tryed germing one seed and that went perfectly untill the shell/husk came off, the first leaves are yellow but the 2 tiny ones inbetween them are still green. Is this normal?? If not what am i doing wrong?

  22. nick April 23, 2014 at 3:54 pm -

    to 1st time it needs nutrients to grow could be because of not using good soil

  23. 1sttimegrower April 24, 2014 at 5:30 am -

    Thanks il try that

  24. 1sttimegrower April 24, 2014 at 5:36 am -

    Thanks nick And to rambo your right about sometimes getting a previously failed seed to germ, i had one that failed using the paper towel method ans so after letting the seed dry out again i tryed the watercup method and over noght it started to sprout, its progress is slow but its growing so i just have to move on to the next step getting it to grow up.

  25. 1sttimegrower April 26, 2014 at 4:02 am -

    The first leaves are slowly opening now

  26. 1sttimegrower May 3, 2014 at 4:48 am -

    It died

  27. Lars May 6, 2014 at 7:48 am -

    Hello.I have always used the papertowel method,and put the plates on the heated floor with a temp probe inside.I have germinated a lot of seeds and have a germ rate of 95%:))But i have read that this method is not good?Now i have 6 Rocklock fem seeds and 3 clusterbomb fem seeds(2 was missing from the package:((.I have newer tried too put them in a glass of water but should i try this or just do it like a always do,with good and fast results?What ph and ec should the water have?Kind regards from me:))

    • kenny. June 9, 2014 at 7:12 pm -

      Ya Lars..buddy old pal…the cup of water is the best method. 100% germ rate for me. Im on about 50 plants grown that I germinated this way. Happy growing!! 🙂

      • kenny. June 9, 2014 at 7:15 pm -

        Just remember…distilled water. I also add about two tablespoons of vinegar per gallon of water only due to the acidity in black gold worm castings and the bone meal I use for fertiliser. ..also I use l.e.d.s and ive had nothing but max yields for about 4 years now..

  28. May 21, 2014 at 3:41 pm -

    Hello there! This post couldn’t be written any better!
    Reading this post reminds me of my good old room mate! He always kept talking about
    this. I will forward this post to him. Fairly certain he will
    have a good read. Many thanks for sharing!

  29. kevin May 28, 2014 at 6:50 pm -

    How do I get rid of bugs,

  30. kevin May 28, 2014 at 7:02 pm -

    I have small bugs. How do I get rid of then?

  31. saselc1 June 7, 2014 at 8:02 am -

    Thanks for the tips!! I’ve had 5 seeds that I took out the my bud sack that I thought, hey let see if these will sprout. So I put them in a slightly more than damp paper towel in a tiny pot in the back lanai..I live in south Florida so I thought the heat & light would be fine. Today is the third day & they are progressing nicely with little taproots. About to plant them according to your steps above tomorrow. We’ll see how it goes. Thanks again!!

  32. asdfjddlsl June 19, 2014 at 9:02 pm -

    i am skeptical of talking on the internet. so il be brief, thank you. this method works well.

    • feds July 6, 2014 at 2:53 pm -

      you made yourself sound like such a sketch mf

  33. jeff July 19, 2014 at 1:05 pm -

    I just got my seeds a day ago and am about to plant them outdoors. I have read a bunch of info on websites regarding outdoor growing, but I live in Costa Rica while most info is geared towards North American climates. The area I live in is fairly dry but we are about to enter the rainy season. My main question is how many hours of direct sunlight do you think I should allow my seedlings to get. Also if there is any other wisdom that you could share with me regarding growing in a climate where it is real hot every day of the year

  34. elmacho321 August 19, 2014 at 8:48 pm -

    I am an inexperienced grower. I’ve tried about 6 times to get a seed to sprout,they germinated properly but when I put them in soil I waited about a week and they never sprouted,so far I’ve only had one success,I’ve used the same soil every time (a little cow manure and some good soil from a friends ranch) and used bottled drinking water,I water them when the soil feels dry,i leave them outside to grow,am I doing something wrong or were the seeds just not that good?