Autoflowering cannabis seeds are just like any regular ones and the process of germination is the same, in fact, the only differences are in the way you treat you seedling when it has sprouted. Some growers say that autoflower seeds can be germinated in colder temperatures but I have not tested this hypothesis myself and have not seen side by side tests that show temperature differences and autoflower seed germination rates.
There are basically two methods of germinating autoflower seeds and they are natural seed germination and germination without growing medium. In nature autoflowering cannabis seeds usually drop down in the autumn, then they survive the winter and in the spring when the temperature reaches optimal level and the surrounding area gets moist they start to germinate. Autoflowering seeds don’t like overly wet conditions and if the seeds drop into a puddle or any other water reservoir or even a swamp then they usually start rotting and die. Looking from the other extreme when a cannabis seeds germinate it looks for a wet environment and if the tap root encounters a dry environment it shivers and dies. From the environments that these seeds encounter in nature we can see that they need to be really strong to survive different conditions and that is why autoflower growers in perfect conditions can achieve more than 99% seed germination.
Autoflower marijuana seeds can germinate in a wide range of temperatures. The optimal temperature for the surrounding air is 27 degrees Celsius but a bit of variation won’t harm the germination rate.
The soil temperature should be a bit lower and it should be around the 25 C mark, but again a little variation won’t affect the germination process that much.
If you are in a colder environment you need to get a heating pad that can heat up your growing medium and if you are in a hot environment get some fans or install an air conditioning unit.
More about autoflower temperature you can find in my previous post!
Autoflowering germination process requires a certain amount of water and water is the life-juice of the seedling that encourages it to start the growing process. Cannabis seeds require clear water, they can be germinated in tap water but you should check the PH level of it because it should be in the 5.6 – 6.2 range, but you can also use distilled water.
You should definitely avoid any nutrients at the germination process and first weeks of growth because the little seedling has a certain amount of nutrients inside the seed, and too many nutrients can halt its growth.
Growing medium preparation
Before putting your seed inside a growing medium you should fully wet that medium by flushing and only after it has dried up a bit you can put the seed in it. Almost any growing medium will be suitable for autoflower seed germination and you just need to check if the PH level is not too high or too low.
After the seed is put inside that growing medium, keep it damp but not too wet as the too humid environment can cause bacteria to spread rapidly causing the new seedling to rot away.
Natural autoflower seed germination
Just take your autoflower cannabis seed and put it in a wet growing medium 2 to 3 times as deep as the width of the seed. That little plant will shoot its tap root down into the ground and with those seed leaves will try to find the light.
Because the seed leaves are growing as they search for the light they will sprout into the air and the little seedling will be firmly held into its place by the taproot. If you plant your autoflowering seeds any deeper the seedling will struggle to push itself towards the light but if you plant it right at the surface the root can get in the light that can stun the plant’s growth.
This is the easiest germination method and this is how nature intended the seeds to be germinated, so you can pretty easily germinate seeds this way and they will pop 90 to 99% of the time depending on the seed quality and age.
Some growers prefer to put the seed in water for 24 hours before planting it in the ground but that does not increase the germination rate for young seeds and usually is done for older seeds.
This method is easy and if you don’t put those automatic seeds into the water for soaking then you just need to dig a small hole and put that seed inside.
This method is the least stressful for the little seedling as you don’t move it around and the soil acts as a buffer if there are any temperature or light fluctuations.
One of the disadvantages is that you cannot control every aspect of this germination process and you can’t know which seeds will germinate and which won’t.
This not knowing also creates a need for more pots and ultimately can cost you money because some seeds will not germinate and you can’t tell which will, but you need to plant each of them inside a different container.
Autoflowers are no good for transplanting and if you want to grow your plants into 5-gallon pots then you need to put each seed inside the end pot/rock wool cube and if some of them don’t germinate you have wasted your resources.
Autoflower starting without growing medium
This is a common method between experienced growers as it gives them full control of the germination process but in a sense is a bit more difficult. This germination method has a number of variations but the most common is the method of putting autoflower seeds in a wet paper towel in an almost closed environment.
If you are using this method you need to control your humidity and it should be at the 80 % level. You also need to control the temperature of the surrounding air because there is no buffer (soil/rockwool) that can protect the seed.
You also need to put your seed germination tray in a dark room and twice a day check if the paper towel has not dried yet. I will give an autoflower germination guide (wet paper towel method) at the end of this article.
Growers can see which seeds will germinate and put only those seeds in their containers not wasting any materials.
By germinating autoflower seeds in this manner you also have full control over the germination process and you can give the seed perfect condition for germination.
Seeds will also pop faster than if they were grown right in the growing medium!
Inexperienced growers can damage seeds while handling them to their growing medium or just getting some of the environmental variables wrong.
If they are left in the paper towel too long the growth can be stunned and they can even die.
This method requires a lot more work than just putting seed into the ground. Basically there are more things that can go wrong.
How to germinate old seeds?
Old seeds are those cannabis seeds that have been produced some 3 and more years ago but that doesn’t mean that you can’t germinate them.
Usually, seeds stay valid for 3 to 5 years if stored properly but with every passing year the seed germination percentage drops and it is harder and harder for you to germinate them. In time the seedling inside the seed loses its moisture and starts to shrink getting weaker and weaker up to the point that it is no longer alive and no moisture levels can’t bring it back to life.
The process of germinating old autoflower seeds is similar to regular seed germination, but you need to let them soak in water for a while so that the seed shell can soften and moisture can get inside the seed giving energy to cells to crack that shell and push out the tap root.
In the picture below you can see seeds in water soaking up that moisture. One of these seeds has drowned and two are floating on the top.
Usually, seeds will drown in a couple of hours and if they don’t drown in a day or two then they could be damaged. This drowning indicator is not as viable because the water surface pressure will hold even the healthiest seeds floating so you can gently push them down and if they don’t sink then, the seeds are probably damaged.
Autoflower growers usually let old seeds stay in water for 24 hours before putting them inside a growing medium or putting them in a paper towel, but be careful as leaving them in the water there for longer can harm them!
While germinating seeds you can easily stress them so you need to look out for the environmental stresses that can damage your seed germination rate.
The first thing is the light cycle fluctuations and the light itself. When germinating autoflower seeds they should be in complete darkness and no light should be shining on those newly sprouted tap roots, as it happens in the ground where there is complete darkness. After the seedling has sprouted you should not change the light schedules and let those newly grown plants grow in perfect conditions.
The second stress that those seeds should not encounter is temperature fluctuations as they can also damage the germination rate, in the ideal conditions temperature should stay the same all the way till the autoflower seed has sprouted and won’t dip in the night time or rise in the daytime.
The last stress that can damage the newly sprouted tap root or seedling itself is nutrients. For the first days and weeks of cannabis growth, you need to supply only pure water with no salts and nutrients.
Method for fixing seeds that are not sprouting:
If you tried to germinate your seeds and some of them did not crack open after 5 days or more you have one last hope and it is to gently try to crack open the seed shell hoping not to damage the seedling if it is still alive.
This method is not going to work 100% of the time and in most cases, you won’t get even 50% success rates but you can apply this method as the last resort if that seed doesn’t sprout naturally.
You can do this in a number of ways and the most common are:
Try to crack it open between your teeth, by lightly crushing one end till the seed shell breaks.
Another method is to do this with tweezers trying to get an opening at one end
The last method is just taking a small knife or scalpel and cutting around the seed till the seed shell breaks off, but you should be very careful not to damage the seedling if it is still alive.
Autoflower seed germination guide
First of all select a viable cannabis seeds that you will be germinating. You need dark-colored seeds that are strong and not too old. If you bought your autoflower seeds from a seed company then you probably should not worry about the quality of them as usually seed companies sell only the best quality seeds.
After selecting the best autoflowering seeds you have two options: putting them right in soil or germinating on wet paper towels. In this guide, I will show the second method.
You will need a container, clear water, and paper towels. For this autoflower seed germination guide, I chose to document one of my micro grows with a yogurt container as a pot, but the principles are all the same for any grow and the basic germination methods stay the same!
First of all, you need to germinate your selected autoflower seeds!
- So take your container (in my case a plastic food storage box) and clean it properly so that there is no dust or any other contaminants inside it.
- Take that paper towel and fold it in multiple layers so that it can soak up more moisture. I usually fold 2 or 3 layers and then fold that layered piece in half and put it inside the container.
- Wet the paper towel to the point that it is completely wet but if you take it out of the box the water won’t drop off it. Also, there should not be excess water inside your container, because cannabis seeds like moist but not completely wet environment. You can moisten it by pouring water or by misting with hand sprayer.
- Take the lid off the plastic box and cut two holes inside it so that some moisture can escape that homemade humidity dome. Autoflower seeds germinate best at around 80 % humidity and 100 % is too high as it also increases the risk of fungus or mold growth.
- Gently take your selected cannabis seeds and put them inside the wet paper towel and fold it on them. After the folding gently push that towel on the seeds so they come in full contact with it.
- Put the lid on the container and put it in a dark environment where the ideal temperature should be around 27 degrees Celsius.
- Let those seeds germinate for two to three days depending on the strain and quality of the seed. You need to check your humidity dome twice a day as it can quickly dry out and kill those seeds.
- After a day or two you will see the seed shell opening and a small tap root coming out of it. Don’t let that root get too big as it can grow inside the paper towel and then moving it will hurt the seedling and can even kill it.
Planting a germinated seed!
- Prepare your growing medium by saturating it with water and letting it drain off!
- Create a hole in the dirt two to three times deep as the width of the seeds. The growing medium should be moist but not completely wet at this point. I choose to put this seed in organic soil.
- Carefully take that seed by its seed shell and put it inside the growing medium. Be careful not to damage the tap root. It is best to not touch it at all just take your autoflower seed by the shell.
- Gently push the growing medium around the seed and let it fully germinate monitoring the temperature and humidity levels.