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How to Germinate Cannabis Seeds

Just received your cannabis seeds in the mail? Great! Now what?

Now you germinate your seeds. But what does that mean, and how do you do it? Once again, Seedsman has all the information you need. This article will look at the germination process – both what it means and a step-by-step look at how to do it. Bookmark this one for future reference.

What is Seed Germination?

Put simply, germination is the first step when growing marijuana plants. It’s the first step in the cannabis plant life cycle before planting or potting your seeds, where the seed goes from seed to seedling. The shell will crack, and (all being well), you’ll see a white root emerge.

This sprout is known as a taproot, and it’s the first sign of life to burst forth from your seed. There are several different ways to germinate cannabis seeds, most of which are pretty straightforward. We’ll look at these methods in a bit more depth, and you can decide which method is best for you – and your seeds.

Getting the germination stage right is crucial to getting your cannabis cultivation off the ground. There’s a high chance of failure, and how you store your seeds, as well as how you handle them before attempting germination, is vital. If you get it wrong, your seed is useless, and you’ll have to try again with a new seed – but don’t worry! This guide will give you all you need to know to get you germinating seeds like a veteran.

Before you get started, there is a small caveat – even the most seasoned cultivators will often find themselves with a dud seed or a few dud seeds now and again. Taking great care of your seeds and using the proper techniques will serve you well, but sometimes a seed just won’t sprout. Bear in mind a seed is a living organism, and sometimes you’ll get a seed with bad genetics. If this happens to you, toss it aside and start again.

Inspect Your Seeds

Cannabis seeds are just the same as any other seeds in that they’re not all created equal. Upon opening the package, you may notice seeds of different sizes and colours. This is normal, and the shape and size of the seed aren’t indicative of its quality.

There’s a consensus among the experts that the colour of the seed may be a quality marker. Darker seeds may have greater viability, and pale green or whiter-looking seeds are more likely to fail. That doesn’t mean tossing out the pale ones, however. Germinate them all and see how you fare. Even a seed with slight damage to the outer shell can sometimes germinate and grow to produce good plants.

It likely suggests a good seed if a seed has a tough shell and can take a squeeze without sustaining any damage. An immature seed will typically be of a paler colour and more prone to shell damage if pressure is applied.

What’s the Score?

Some cultivators believe in scoring the seed’s outer shell with a sharp object before germination. This process is also known as scarification and is a good way to assist in the germination process. The idea is that weakening the seed’s outer shell makes it easier for moisture to permeate the hard shell. This should speed up the process somewhat and make it easier for the taproot to burst through.

Feel free to try this method, but take great care. Also, note that if you’re a hobbyist, scarification is fine, but if you’re a licensed cultivator with dozens of plants, you might find scarification to be an unnecessary, time-consuming endeavour.

As scarification involves a sharp implement (such as a pen knife or a thin file), there’s a reasonable chance you could nick yourself in the process. Your seed is at risk of damage because if you score too deep into the shell, you can damage the embryo inside the seed. Sure, you can toss the seed aside and start over with a new one, but can you say the same about your finger?

You can nip seeds with nail clippers to scarify them, but remember not to squeeze too hard – the aim is to put a score in the shell and not pierce it.

Another way to scarify seeds is to soak them in hot, but not boiling, water. Let the water cool to room temperature, and leave the seeds in that same water for around 12 hours.

A Word About Water

Home growers take note – many seasoned cultivators recommend using distilled water rather than tap water when germinating seeds. The advantage of distilled water is that it’s free of contaminants and seems to help seeds germinate quicker.

How To Germinate Cannabis Seeds

Once you’ve inspected your marijuana seeds and scarified them if you choose to, it’s time to begin the fun part – germinating your seeds. This is the first step in the life of your cannabis plant when the initial shoot of the plant appears, long before putting the plant under grow lights or into a growing medium. Seeing your first taproots is an exciting experience and is often documented like the imminent arrival of a child with a series of photographs from bump to birth.

Let’s talk about germination methods:

The Wet Paper Towel Method

This is a favourite of hobbyist cultivators worldwide, mainly due to its sheer simplicity. To germinate cannabis seeds using the paper towel method, you’ll need the following:

Cannabis seeds (of course)

  • Two plates
  • Four paper towels
  • Tweezers
  • Distilled water

Begin by laying the paper towels out flat. Dampen them with distilled water, enough to moisten without saturating them – you want them to be moist but not wet. Lay two of your dampened paper towels on top of one of the plates, and using tweezers, place your seeds on top of the paper towels a few centimetres apart from each other. Then, take the other two paper towels and lay them on top of the seeds. Finally, cover the lot with the last plate to seal in the moisture and create a nice, dark environment for your seeds.

germinate cannabis seeds

Store your plates in an environment where the temperature is between 20°C and 30°C (68 to 86 degrees Fahrenheit) and check on them twice a day. You can buy a heating mat online to help create a stable temperature. Top Tip – if you find the paper towels are drying out, add a little more distilled water to keep them moist.

Resist the temptation to check on them regularly, as you don’t want to keep disturbing the ambience between the plates. Using the paper towel method, you should see taproots emerge within the first three days, although some strains and older seeds may need a little more time. When you have taproots measuring 2-3mm, remove your sprouting seeds and plant them in the soil.

It’s that easy.

The Glass of Water Method

A less common and perhaps less effective method is the glass of water method of germinating seeds. Here, you’ll need:

  • Seeds (of course)
  • A cup/glass/bowl – small container of water

First, ensure the water is at room temperature. Don’t heat it, don’t boil it, don’t pull a bottle of Evian straight from the fridge and have at it. Then, simply pop your seeds in and check back the next day. After somewhere between 3 to 5 days, you should find that your seeds have opened and those magical white tips have appeared. Once they’re around 2-3mm long, remove the seeds very carefully, and plant them in soil pots.

germinate cannabis seeds

This is the simplest germination method, but the internet is awash with contradicting views and sob stories about using the glass of water method to germinate cannabis seeds. Some people found that seeds effectively drowned and were useless due to spending so long in the water, but others reported the process worked fine.

Soil Plugs

A slightly more hi-tech method of germinating your seeds involves using soil plugs. These contain ingredients such as key nutrients which should benefit seedlings to thrive. By investing in soil plugs, the idea is that you’re strengthening the plant from its earliest stage of life and providing head-start protection. Soil plugs can assist nutrient uptake and protect against pathogens which could attack the root zone.

For this method, you’ll need the following:

  • Seeds (of course)
  • Soil Plugs
  • A propagation tray
  • A spray bottle
  • A clear plastic lid (Tupperware style)

Begin by placing a single seed into each plug, then place each plug into the propagation tray. Grab your spray bottle and set it to mist to avoid overwatering, then mist each plug with just enough water to moisten them.

germinate cannabis seeds

Then, pop your lid on the propagation tray to retain the humidity inside the tray. It would be best if you aimed to keep the temperature somewhere between 22°C and 25°C and relative humidity between 70% and 90%. Once roots begin to appear, soil plugs have the benefit of allowing easy transplant into soil, rock wool, coir or hydroponics systems.

The Soil Method

The advantage of planting seeds directly into potting soil is a notable one – you want to minimise handling as much as possible at this stage, and the soil method allows you to skip that altogether. For that reason, planting straight into soil is probably the safest method of germinating cannabis seeds.

You’ll need:

  • Seeds (of course)
  • Small pots
  • Premium quality soil
  • Water
  • A spray bottle

Soak the soil you’re going to be using in water, and fill each pot with soil. Make a small hole about 15mm deep in the centre of the soil, then carefully place one seed in the hole in the soil in every pot. You’ll then lightly cover each seed with soil, but take great care not to compress the soil over the seed. Doing this will make it much harder for the root to break through the soil and can slow growth significantly. A light dusting over the seed should do the trick.

germinate cannabis seeds

After this, lightly spray the top soil with water to keep it moist. Then, place the pots in an environment in that temperature sweet spot between 22C and 25C. It should take between four and ten days for the seedling to sprout in this method, but as it’s already in soil, the plant’s roots will also have started to spread underneath. The result is a plant that’s underway and has enough resilience that you can transfer it – and the soil – to a larger pot for the next stage of young plant growth.

Different Methods, Same Conditions

Once your seeds have germinated, pot them and transfer them to a windowsill to give young seedlings some light. You won’t have to worry too much about nutrients at this stage, but once you see the first set of leaves emerge (known as cotyledons), slowly introduce nutrients at around a quarter of the recommended dose, increasing in quarter increments per set of leaves.

Remember that no batch of seeds comes with a guarantee that 100% of them will germinate. Any of the above methods will successfully germinate most of your seeds, but no matter which way you choose, there are key conditions that remain consistent with each.

In nature, seeds germinate in springtime, so we want to replicate those conditions – warmth, humidity, and moisture are vital. Keep handling of your seeds to a minimum, and remember that checking a couple of times a day is recommended. Germinating cannabis plant seeds can be an exciting time, but resist the temptation to check in every 90 minutes.

Finally, buying your seeds from a top quality and trusted seed bank like Seedsman ensures high-quality genetics, which increases the likelihood of successful germination.

Got any top tip tips or hacks for germinating your cannabis seeds? Share them in the comments below.

Cultivation information, and media is given for those of our clients who live in countries where cannabis cultivation is decriminalised or legal, or to those that operate within a licensed model. We encourage all readers to be aware of their local laws and to ensure they do not break them.

Duncan Mathers