How to Germinate Cannabis Seeds

How to Germinate Cannabis Seeds

10 mins read

Germinating cannabis seeds can be done in several ways. Often, these seeds come with an expensive price tag – so it’s worth finding a method that personally works and then sticking with it. For that reason, we wanted to put together a list explaining how to germinate cannabis seeds, with the help of guest author Aaron Nacci from Aztechlife.

How to Germinate Cannabis Seeds, How to Germinate Cannabis Seeds, ISMOKE

First, let’s cover some basics before we delve into our feature How to Germinate Cannabis Seeds.

In all methods, the basic requirements of the seed will be the same. The first stage is the imbibition stage which means to “drink water.”

How to Germinate Cannabis Seeds, How to Germinate Cannabis Seeds, ISMOKEThis is where the seed absorbs water to start growth. Going into a bit more detail, the hydration activates stored foods and enzymes which trigger the seed’s metabolic process.

This is the stage that you’ll notice the seed will crack open. Once this happens, the seedling will be looking to photosynthesise.

Once the seed is cracked and a healthy white taproot begins to emerge it will soon need Moisture, Warmth, Oxygen, Nutrients/Micro Nutrients and Light.

Great! Now that’s covered, let’s talk about some of the different ways you can germinate cannabis seeds:

Jiffy Pellets and Root Riots

How to Germinate Cannabis Seeds, How to Germinate Cannabis Seeds, ISMOKEThese two forms are great for both seeds and for rooting cuttings. Root riots are spongy and made from organic materials – usually, this means they are already damp when arrive.

Jiffy Pellets come as dry compact discs and need to be rehydrated before use. Once you’ve soaked your Jiffy pellet (or Root riot if dry) you will need to squeeze out any excess water.

Pop your seed into the ready-made hole and place somewhere warm ideally between 18 and 28 °C. (64-82 °F) A clean, sterile electric propagator can help at this stage.

How to Germinate Cannabis Seeds, How to Germinate Cannabis Seeds, ISMOKE
Image: Grow Weed Easy – How to Germinate Cannabis Seeds

You will need to make sure the seed is kept moist at all times and should take care not to let the cube/pellet dry out completely. If it’s too wet though, the growing seed will struggle for oxygen and may even rot.

Tip: A fine garden mist sprayer is an easy way to keep the moisture levels stable by spraying as needed.

Paper Towel Method

How to Germinate Cannabis Seeds, How to Germinate Cannabis Seeds, ISMOKE
How to Germinate Cannabis Seeds: Paper Towel Method

The paper towel method is a pretty simple and common technique for growers to use. Toilet paper or paper kitchen roll is moistened water at room temperature.

The excess water is squeezed out and the seeds are then placed between two sheets. The seeds need to be placed somewhere dark and warm somewhere between 18-28° C (64-82 °F).

Two small plates can be used for this – one placed upside down over the other one. Actually, any container will do, provided you can make it light proof.

The paper shouldn’t be allowed to completely dry out, but it shouldn’t be too wet either. Once you have a healthy white tap root emerging, the seeds will need to be transferred into soil or other chosen growth medium.

How to Germinate Cannabis Seeds, How to Germinate Cannabis Seeds, ISMOKE

Tip: Airing cupboards are especially good for this purpose, but a warm windowsill will do the job.

Soaking in Water

How to Germinate Cannabis Seeds, How to Germinate Cannabis Seeds, ISMOKE

Seeds can be soaked directly into a glass of water at room temperature. Bottled water or rain water is ideal, but in most cases, tap water should be fine.

Pre-soaking the seed is highly recommended for older seeds that have been stored for several years. Some growers will place their seeds in water for 24 hours then transfer seeds straight into their compost. This makes sure the seed has had a good initial soak and has likely been activated.

The other method is to keep your seeds in the water until the seed cracks. Good seeds will sink and eventually a white tap root will emerge – using a glass will make it easy to see this stage.

When your seeds are at this stage they will need to be taken out and transferred soon because they will be starved of oxygen whilst under water.

Read 10 Facts about Cannabis Seeds

Straight into Compost

How to Germinate Cannabis Seeds, How to Germinate Cannabis Seeds, ISMOKE
Image: Spliffseeds

This method is also pretty straightforward and could be done after the 24-hour pre-soak previously just mentioned.  There are however a few things to follow to ensure a better success rate.

Avoid old compost, especially if been stored a long time and is damp. The compost could contain pests such as fungus and gnat larvae that will happily munch through your emerging tap root.

Where possible it’s recommended to use a specific seed compost. These often have additions such as sand, vermiculite and perlite to improve drainage and aeration. They also only have a low-level nutrient content, which is ideal for the early stages of seed development.

However many growers do have success with general multi-purpose compost available from supermarkets and DIY stores. You can always add your own perlite or vermiculite (also available from garden centres and online) to the soil yourself and just mix up the amount you need.

Tip: If you are getting your compost from a specialist grow shop, you will really want to make sure it is suitable for seeds or called a “light mix”. Other grow shop specialist soil blends are likely to be for more mature plants and will be too nutrient rich for seeds.

Temperatures will need to be maintained at around 18-28° C (64-82 °F).  A propagator is good for this, but similar results can be achieved by putting a small clear plastic food bag over a pot secured with an elastic band. The bag should be removed as your first seeds begin to appear above the surface.

Rockwool Slabs or Cubes

How to Germinate Cannabis Seeds, How to Germinate Cannabis Seeds, ISMOKE

Using Rockwool is a method often used by hydroponic growers. It is the most advanced of the five methods listed here but uses equipment all hydro growers have to hand.

Hydroponics is the process of growing without any soil at all, which we’ll cover in another article. Using this method, All the plants nutrient and micro-nutrients are provided within the water in the hydroponic reservoir added and maintained by the grower.

Rockwool has a slightly high alkaline content, and will, therefore, need soaking in water adjusted to a PH level between 5.5-6.5. You may also use a weak nutrient solution too such as Formulex in with the soaking liquid.

Place your seeds in these cubes and place them in a warm environment to germinate. It is important at this stage not to let the cube dry out completely or to be too waterlogged.


While the start of germination requires no light at all, after your seeds have cracked they should be placed where they will get a reasonable supply of natural light.

In indoor environments, your seeds and early seedlings only need a low wattage and a cooler heat output light to start.

Tip: Fluorescent tubing is often used for this, but even a desk lamp with an energy saving bulb in would do the job.

We hope you’ve enjoyed our How To Germinate Cannabis Seeds feature on ISMOKE Magazine.

How to Germinate Cannabis Seeds, How to Germinate Cannabis Seeds, ISMOKENote: Germinating cannabis seeds may be illegal in your country – consult the laws before undertaking if you are in doubt, as explained in this wikihow article.

If you have anything to add to our guide on how to germinate cannabis seeds you can email [email protected] – the idea is to keep updating these guides with new knowledge and information from the cannabis community.

Leave a Reply