How to germinate cannabis seeds

How to germinate cannabis seeds

Germination from seed is the very beginning of life for your cannabis plant. Each viable seed contains all the information needed to grow a plant just waiting for the right conditions to be able to express itself. Seeds wait to germinate until three specific needs are met. Water, correct temperature (warmth) and a good location, usually in a growing medium.

During the early stages of growth, everything the seedling needs is provided by the seed itself. Ample nutrition is supplied to last the seed until it has grown enough to start producing its own food by photosynthesis.


First, the seed absorbs water through its husk by imbibition which means to imbibe or drink. The water hydrates existing enzymes and food supplies causing the seed to swell and expand. As metabolism gets stronger hydrated enzymes become active increasing energy production for the growth process.

At the same time, water increases turgor pressure encouraging cell expansion. The first indication of life will be the cracking of the seed coat and the emergence of a small white shoot called a radicle. This quickly lengthens and becomes the tap root. The new tap root pushes down into the grow medium anchoring the plant in place and begins to absorb water and nutrients.

Simultaneously the new stalk reaches towards the light and leaves begin to form. The first leaves to appear are oblate, thick and rubbery and are not really leaves. They are called 'cotyledons' and are pre-formed inside the seed. When hydrated they swell considerably and are used to split the seed husk apart and protect the first true serrated leaves as the crown is forced up and outwards through the medium.

Soon a radical transformation happens called photomorphogenesis. This light-dependent process makes the plant become green and begin photosynthesis.


Growing cannabis, just like other plants, is an organic process without a strict set of rules. It is not a linear system to learn, but an art to be mastered. Over time you will develop your own personal alchemy based on your successes and consistently reap super yields.

There is no single specific way to germinate cannabis seeds. Different growers will usually choose to use one germination method that suits them best.


How to germinate cannabis seeds

This most closely resembles what happens in nature. Some growers will plant directly into an easily managed small starter pot or a seedling tray full of the medium in which the plant will spend its whole life. This could be soil, perlite, coconut coir or your choice of combination.

As the plant becomes a strapping cannabis seedling in need of more shoulder space and root room it will be potted on into a bigger container. Other growers will plant the seed directly into the largest container straight away so as to avoid any risk of transplant shock.

Both methods have their advantages and disadvantages. Potting on from a smaller pot runs the risk of root damage, transplant shock and more uncommonly root infections. The upside being the plants are easier to manage in the early stages of life when they get substantial attention with topping and low-stress training.

Germinating in the larger container runs the risk of overwatering and soil saturation in the bottom of the pot causing moulds and algae. The benefit being up to an extra week of undisturbed growth.

To plant your seed:

In the centre of the pot push your finger into the moistened medium up to 1cm and gently place the seed. Fill over the seed and water into place. It is a good idea to tamp the medium when filling your pots, simply tap the bottom of the pot a few times on your work surface.


How to germinate cannabis seeds  in a paper towel

This method is preferred by those who want guarantees about the viability of their seeds. There is no question when seeds have germinated. This gives complete control over the amount of active space in any grow setup.

What you will need:

  • Two plates
  • Unbleached paper towel
  • A plastic bag or cling film
  • Clean water
  • A warm dark place

-Place three layers of paper towel on a plate and moisten well by soaking the paper towel then draining. Things should be wet, but not swimming.

-Place your seeds onto the moistened paper towel spaced well. Remember you will need room for your fingers to grab them when sprouted and good distancing stops roots from tangling if you mistime things.

-Place another three layers of moistened paper towel flat over your well-placed seeds. Do so in a way that lets you identify the edges of the top layer so it can be removed with as little disturbance as possible when needed.

-Now place in the plastic bag or cover in cling wrap to ensure humidity and to stop the towel from drying out. You can use the second plate as a lid but there is a risk of dehydration as this is not an air tight seal.

-Place in a warm dark place or on a heating mat. Sprouting time depends on species. Some rapid indicas will be ready to pot after 24 hours. Some other species may take five days. Try not to disturb your seeds too much. Generally, you can see an outline of the root-shoot through the paper towel. Pot your seeds as they sprout.

-Once sprouted make a 1-1.5cm deep hole in your selected growing medium and put the sprout root point down, cover over, gently water in and place under your vegetation lights. If the tap root has wound around the seed rather than being straight still put it in the medium point down. The seed will do a clever unravelling which helps remove the seed husk as it makes its way to the light.

-There is no need to freak out if you have mistimed things and the seeds have completely sprouted. Perhaps the tap root has even grown into the paper towel. All is not lost, only sometimes. Just be very gentle when handling them. Make the hole in your medium as deep as the tap root. They will certainly survive as long as the tap root has not been damaged or broken.

Don't be disheartened if some seeds don't make it. That's just the way it is sometimes and it isn't necessarily your fault. If it keeps happening, review your process or contact your seed supplier.


Other growers opt for grow plugs or jiffy pots to save space during the germination period. Grow plugs have the advantage in that they are ready to go, already moistened straight out of the bag and are made with the cannabis grower in mind. They also come in handy pre-prepared trays. However, they must be used promptly or they will dry out.

Jiffy pots or similar are easily stored dehydrated peat pots and need to be soaked before using. This does have the advantage of being able to customise the nutrient and enzyme environment of the germination medium. Simply add your personal witches brew to the water before reconstituting. Plain water is okay of course.

Both products come with handy pre-made holes which are of a depth just right for baby ganja plants. They have a flat bottom, stand up easy and are a super simple way to germinate your cannabis. They have the distinct advantage of being able to be potted on with little root damage and interruption to growth.

Once the first roots are visible gently pot on to an intermediate pot or the final large pot.

- Simply drop your seed into the prebored hole and cover it with soil.

- Place on a heat mat and humidify.

Grow plugs and jiffies are also just as good for cloning. Just put your root gelled clone into the pre-prepped hole squeeze and humidify.


Some people like to pre-soak their cannabis seeds before they continue with one of the methods above. This can be done by simply putting them in a drinking glass of lukewarm, clean water for 12-24 hours.

Pre-soaking seeds will soften the shell and gives the plant an early mini-boost. Especially with older seeds, this is an advantage. Older seeds get a drier and harder skin. By pre-soaking them first in clean water it increases the chance to a good germination rate.


Rockwool can be regarded and used in the same way as plugs or jiffy pots. The issue with rockwool cubes is more a moral one than anything to do with their cannabis growing ability. They are inexpensive, easy to use and function very well and are used extensively in the pure hydroponics industry.

However, they don't really have the best environmental cred with regard to their manufacture or dispensability. It would be difficult to consider them organic that is certainly the trend in contemporary cannabis demand.