Why won't my cannabis seeds germinate? Why are my seedlings weak? Find out the answers to these questions, and their solutions, in our troubleshooting guide. Cannabis seed germination is the first step of cultivation, and if we make a mistake in this first phase, any subsequent effort will be in vain. There are several germ… Hey so I planted about 10 seeds 5 days ago, all were rooted aleast 1/4 or an ich to a 1/2 an inch.. So when I planted these seeds, I planted them all about…
Cannabis Germination Troubleshooting
Here we offer numerous tips on avoiding issues during the germination and seedling phases of your cannabis grow. If your seeds aren’t sprouting, or your seedlings are struggling to grow, you’re likely to find the reason for your problem, and its solution, in this guide!
Before you can start tending to your crop of weed plants, you have to get those sprouts out of the ground first! Germinating cannabis seeds can be quite a fiddly process, as can looking after the newly hatched weed seedlings. Find out the common issues cannabis growers face during the germination and seedling stages, and their solutions.
Common cannabis germination issues
Throughout the whole cultivation process, but especially in the earliest stages, careful and exact practice will make success much more likely. Seeds and seedlings are vulnerable and can die or become stunted easily, or even fail to germinate at all.
Below, we’ll break down each potential issue you could experience during these early stages of your grow, and what you can do to remedy the situation.
Cannabis seeds not germinating (day 0)
If your seeds aren’t germinating at all, it could be for one of the following reasons.
Maybe you found some seeds in a bag of weed and thought you might try growing them, or perhaps you bought them super cheap somewhere. It could even be that you got seeds from a great breeder, but they’re just duds. In any case, poor-quality seeds have a much lower chance of germinating or producing viable plants.
Get some good seeds! This needn’t be too hard. Genuinely good-quality breeders perform rigorous germination rate and quality tests, meaning the vast majority of them should be healthy and capable of sprouting. Of course, there will always be exceptions, but buying from a good breeder or seed bank will greatly increase the chances of successful germination.
Click here to browse countless varieties of regular, feminized, and autoflowering cannabis seeds from the best banks in the world.
Handling seeds with bare hands
Hands can carry all sorts of pathogens, such as bacteria and fungal spores, that can contaminate seeds and seedlings. At this young stage, they are very susceptible to infection, so avoiding direct touch is best!
Be hygienic! If you want to be properly sterile, wear latex gloves or use sterilised tweezers to handle your cannabis seeds. If you don’t want to do this, then at least thoroughly wash your hands prior to handling your weed seeds or seedlings.
Depending on where you live, tap water could be full of compounds that will inhibit your seeds from germinating. Chemicals such as chlorine can be very harmful to seeds and young cannabis plants. Later in a plant’s life, tap water is a much safer bet—although it’s worth figuring out its mineral content so you can feed properly.
Use purified or bottled water. It might seem indulgent, but they’re only young, and this is a crucial stage in their little lives, so give them what they need, and they’ll reward you later on!
Seeds not buried deep enough
If seeds aren’t buried deep enough, they won’t have enough moisture, and can dry out. Moisture is what triggers the sprout to break through the seed shell, so this is really crucial.
Generally, it’s recommended to germinate seeds around a knuckle (0.5–1cm) deep in the soil. This is the optimum depth for them. On top of this, germinating in propagation chambers will maintain a high and correct humidity range (around 70% RH or more), increasing the moisture content and likelihood of germination.
Propagator Pro 2
In nature, cannabis seeds sprout in spring, as the temperatures warm up. So if they think it’s too cold, they won’t germinate. Moreover, certain pathogens thrive in cool temperatures, so even if they do germinate, they may not fare as well.
Keep them warm! If growing indoors, this shouldn’t be too hard. A propagation chamber situated in a comfortably warm room should do the job. Even if you intend to grow outside, you can still germinate indoors to give your marijuana seeds the best start and keep them safe from sudden cold snaps. If you want to carry out the whole process outdoors, you’ll have to hang on until you’re certain of mild nights and warmer days, otherwise you seriously risk unfortunate results.
Soil packed too tight
Tightly packing the soil over your seeds, or just burying them too deep, can be a real issue. First, a freshly “popped” seed is (unsurprisingly) not the strongest being on the planet. In fact, it’s incredible how strong new shoots actually are. But bury them too deep, and they will not have the strength to push above the earth. Moreover, they could suffer from oxygen deprivation if the soil is too compacted or they’re buried too deep, and this will stunt development entirely.
As mentioned, bury them only a knuckle deep in the soil, and lightly brush a covering back over them and pack it down with only the lightest touch. There’s no need for the soil covering to be compact.
Like we said, seeds need moisture to trigger germination. If you haven’t supplied enough water, they won’t sprout.
You don’t need to soak the soil by any means, but you want it pretty damp. If growing in a propagation chamber, you may consider misting the inside with water to promote moisture and high humidity.
The most common mistakes when germinating cannabis seeds
Germinating the seed is the first step in any cannabis grow. It is the process during which the seed begins to develop, and the radicle emerges. There are several methods of germination and there are a number of common mistakes made in each of them, which can be easily avoided.
Here we explain what not to do during germination in each case, and we tell you that the method recommended by Dinafem Seeds is germination in Jiffy, as it is the simplest and has the lowest error rate.
Mistakes when germinating cannabis seeds in Jiffy
Jiffies are dehydrated peat discs, pressed into a biodegradable mesh which, when moistened, become tiny sacks of earth. Water is usually applied so that the wet discs swell and become mini containers of substrate where you can plant the cannabis seed so that it germinates inside the peat. What could go wrong with this method so that we don’t get to see the seedling emerging from the Jiffy?
- Adding too much water to the Jiffy: the disc must be moistened so that it swells, but it should not be drowned. The goal is to keep the soil in the Jiffy moist during the germination process, but never drowned. Some growers water the Jiffy too much, and more often than necessary, and end up drowning the seed because excessive moisture prevents the ventilation of the seed, stopping its germination.
- Covering the Jiffy so that it is too hermetically sealed: the Jiffy has to be protected, but some people shut it away in a germination greenhouse or Tupperware container with holes, increasing the moisture excessively, which leads to the growth of fungi.
- Burying the seed too deep: The seed should be about one centimetre from the surface. Although it is true that the depth of a Jiffy is not more than 10 centimetres, pushing the seed to the bottom of the Jiffy will make it difficult for the radicle to find its way out into the light. Just insert the seed with your finger, near the surface, and cover the tiny hole made when you insert it.
- Not providing it with the right light intensity: in the first germination stage, when the radicle begins to rise up, it is better to provide too much light rather than not enough, because light does not bother cannabis. Of course, in the case of the Jiffy, we must keep in mind that the light, whether from the sun or a spotlight, is linked to the possibility of drying out. So, even if it is good that the Jiffy has plenty of light, we have to make sure that this is not drying the soil too much.
- Subjecting the Jiffy to changing temperatures: changing the temperature for example from 25 degrees (indoors) to 5 degrees (on a terrace) will make germination impossible.
- Putting several seeds in the same Jiffy: these peat pellets are not big enough for several seeds. We should use one for each seed we want to germinate.
- Keeping the seed in the Jiffy for too long. As soon as the seedling has a pair of cotyledons, it must be transferred to the substrate. The Jiffy is small and can only be used for so long before space must be given to the roots to grow in the pot or in the soil.
Mistakes when germinating cannabis seeds in damp cotton wool or paper
The method of germination in damp cotton wool or paper consists of moistening these materials and wrapping the seeds in them. In this case, it is advisable to put these wet fabrics in a germination greenhouse or Tupperware container with holes for ventilation, so that the temperature remains the same throughout the process. So where could we go wrong in this case?
- Letting the radicle grow too much: if the root becomes too long, it will probably end up getting caught up in the cotton wool or paper and will then break when detached from them before being transferred to the substrate. To avoid this, we need to do two things. First, don’t let the root get too long. As can be seen in the photos, the radicle grows very fast, so we have to put it in the soil when we see that it has grown in a certain direction (we can see that it either grows in a straight line or it adopts a more curved shape). Second, do not use pure cotton wool or kitchen paper, but rather cotton fabrics such as rags or pieces of old T-shirts.
- Exposing the seeds to changing temperatures: if we keep exposing them to different temperatures, seeds will not germinate. We must ensure that the place where we put them is warm, between 25 and 28 degrees Celsius, and that this temperature is kept stable until we transplant them to the substrate.
- Leaving the root in contact with the air for too long: left in contact with the air the root will oxidise, which will in turn kill the plant. When the root begins to grow, it is best to transfer it to the substrate immediately. Or, failing that, keep it well covered with the wet fabric.
Mistakes when germinating cannabis seeds in substrate (in a pot or in the ground)
Planting the seed directly into the pot or the ground where we plan to grow is another option for germinating the seed. Let’s have a look at what is usually done wrong in this case, leading to the cannabis seeds failing to germinate.
- Burying the seed too deep: the seed should be one centimetre below the surface and not any deeper. As a general rule for seed germination and cultivation, it is recommended to plant the seed at a depth equal to twice the size of its diameter. It is enough to cover the cannabis seeds, which are small in diameter, with just a little soil.
- Over-fertilising the substrate: the soil where the seed will germinate should be porous and light in nutrients. The substrate used for a flowering plant is not the best choice to germinate a seed, because a marijuana ‘baby’ cannot assimilate the same amount of food as an adult marijuana plant. So, let’s be sparing with the diet in the soil where we have placed the seed to be ‘born’.
- Using a soil with an unknown composition: the soil from the park near our house, or from the vegetable garden of the house in the village are not the best options for germination. It is important to know the composition of the substrate where we are going to plant the seed. And when we take soil from somewhere else, it may contain many minerals, or many nutrients, or a lot of fertiliser, and if we have not bought it in a bag where its ingredients are listed, we will not know its composition. So, it is important to use a substrate whose composition we know, especially for this first step in growing.
- Watering too much: a substrate that is too wet, especially in the case of autoflowering seeds, can be lethal for germination, and for the seedling’s first few weeks of life.
- Putting several seeds in the same pot: unless it is a very large pot, let’s give each seed its individual space so that the roots have enough room to develop. If we put several seeds in a 14-litre pot, for instance, some seeds may end up hindering the development of the others.
- Planting the seed directly in the ground where the climate is not appropriate: if the weather is too cold, too hot, too dry, or too wet it will be difficult for the seed to germinate. Since we do not control the environmental conditions in an outdoor substrate, changing weather conditions can easily hinder the germination of the cannabis seed.
Mistakes when germinating cannabis seeds in water
This method consists of putting the seed in a container with warm water and waiting for it to germinate in the days following immersion.
- Leaving the seed in the water for too long: as soon as it has germinated, and we see that the radicle has emerged, the seed must be transferred to the substrate. Water can be used to germinate it, but never to grow it. So, as soon as we have achieved the goal of placing it in the liquid, we have to take it out of there and provide it with the substrate it needs to survive.
- Overdoing the dosage of hydrogen peroxide in the water: if you want to include hydrogen peroxide to prevent fungi or bacteria during germination, you have to pay attention to the concentration. Overdoing the amount can prevent germination.
Common mistakes of any germination method
- Breaking the radicle while trying to separate the shell from the bulb. Being very invasive in the germination process can be lethal to the seed. Once it has germinated, the seedling will generally eject the seed shell itself, so we should leave the seed to do its job. We recommend intervening only if it is really necessary, and we see that the plant is growing upwards and that the shell is still attached to some of its parts.
- Handling the seeds, radicles or seedlings with dirty hands. We don’t know what type of dirt we might be carrying on our hands without realising it, so we should always wash our hands before carrying out any of the germination processes. This hygiene also applies to each of the tools that are in contact with the seed during the germination period.
- Using dirty water. It is important to use clean tap water at all times.
If you have made other mistakes not described in this post, please share these in the comments section. The growing experiences of some are usually useful to others.
And please, don’t hesitate to ask us any questions you have about cannabis seed germination.
Jásminka Hi, I’m Jásminka, from Dinafem Seeds, and I spend the whole day surrounded by Dinafem Girls. I’m an eager journalist, who lives with the phone glued to my hand, always trying to keep up with the frantic pace of the cannabis world. When something grabs my attention: I ask, listen, write and tell you all I find out on this blog.
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What if my seeds are burried too deep?
Hey so I planted about 10 seeds 5 days ago, all were rooted aleast 1/4 or an ich to a 1/2 an inch.. So when I planted these seeds, I planted them all about 1 inch to 1 and a half inch down in the soil. 5 of the seeds are under a 24 hour light in my closet and the other 5 are in sunlight in a window that should get about 12 hours of sunlight. None of them have sprouted out of the ground yet, and I actually dug up 2 and I could not find the seed. wtf. What I am afraid of is that they all have sprouted the leaves but then died because the leaves were sprouted underground. I am not sure if this a possibility, or if plants are smart enough to keep growing till they break ground. So are my plants going to die or will they just not have enough energy to fully sprout. Please give any info possible thanks!
The leaf won’t grow and die under there an inch ismt all that deep..i put mine like pencil eraser deep. ..You should make sure the seeds are developed fully before planting..white seeds tend to not grow..immature. .Tiger striped and brown with black spots are what to look for. plant seeds and usually two to seven days and they’re all up. what did you plant em in?
Some people like to put the seeds in a wet paper towel in the dark and once they pop open they get planted
The rule of thumb for planting seeds is: four times the width of the seed. So plant MJ seeds about 1/4″ deep, with no light cuz they don’t need it yet and you run the risk of drying out the soil and killing the little sprout before it even pops up.
the best thing to do if you have nice seeds , put them in wet paper towel keep it humid , after 1 week the first leaves will come out and thats the time you put it in soil
None of them have sprouted out of the ground yet, and I actually dug up 2 and I could not find the seed. !
OH MAN. Very common rookie mistake. You are not the first to say that, heck, I’ve done it myself. Trust me, those seeds did not disappear. And by digging around, you dry out the soil at the top, and if you shifted the seed to the top, it will never grow because of no moisture, hence you think it’s a bunk seed, or just vanished. Give up to 7 days. And seeds that get planted an inch too deep WILL make their way out. They literally reach out of the soil looking for light. I speak from experience.
What Dannyboy said is true. And most importantly, BE PATIENT. It’s not uncommon to have a seed suddenly show itself over a week later.
i’ve had a seed pop a month later lol. its shell was too thick and it too a long time to get moistened. if you want the to pop earlier soak the in water for 12-24hrs
Yes I germinated them, I soaked them in water and then put em in paper towels till the root was sprouted about maybe a 1/4 of an inch out, some were a little more, some were a little less. All I know is I buried them way more than a pencil eraser. Like i buried them an inch deep maybe more. a little more than a pencil eraser (considering i used a pencil to make the hole for the seed, hahah. None have sprouted (there are 10) its been 5 full days now.
Luckily when I inspected them I only shifted through 2 of the seeds soil, so I would not mess them all up. I am keeping the soil wet, pretty much when the top layer begins to harden I spray water.
So funny thing is about 20 minutes ago when I checked the little suckers NONE were sprouted AT ALL. and now I go back to add water and wtf. hahah 2 little mofo seeds are NOW popped out of the ground. very happy! I hope the rest come soon!
man just be patient !! all seeds have their time to sprout out. i usually throw away if its already past 10 days. but i always mist the top of the soilless to keep moist all the time, till you see sprout.
Will a 250 watt mercury bulb kill it. or no? Because I know mercury bulbs give off a lot more lumens. Its a Mercury or a mercury HID bulb.
Never heard of mercury bulbs.. MH & HPS are the best but you should buy both MH for veg & HPS for flowering
which aint cheap i would go with T-5 lights which are high output lights and work very well i paid 200.00 for my set.
Mercury vapor is mostly green light. Which is mostly reflected by green plants.