9 typical mistakes when germinating cannabis seeds

Posted on 25. June 2021

Germination of cannabis seeds is a relatively easy and simple process. However, there are a number of factors that are important to know in order to achieve a high germination rate. In addition, it is important that germination goes as quickly as possible, especially if you want to avoid fungal infection or a low germination rate.

If you’re wondering how cannabis seeds actually germinate, you’ve come to the right place. In this blog post, we’ll explain step by step what mistakes you need to avoid in order to successfully germinate your seeds. These are quite straightforward things that are easy to implement, but of course you need to know about them.

Psst. In a hurry to get started with your sprouting? Then hop down to the bottom of the page where we’ve gathered 9 quick tips for successful germination so you can get started sowing your seeds straight away.

If you want to know everything, here are the 9 typical cannabis seed germination mistakes to avoid.



One of the most important parameters when it comes to successful germination is an optimal amount of moisture. Placing the seed in a moist environment starts a chain of reactions that sets the germination process in motion in just a few hours or days.

If you germinate in a germinating tray, e.g. jiffy/coco/drying/green tray or kitchen roll, it is important that this germinating tray never dries out completely. The seed needs to absorb water. If the seed is cut off from moisture during the process, it will likely stop the germination process and never progress.

It is therefore essential that you keep the grout moist throughout the process. If the media is near a heat source, it is especially important to keep a close eye, as this will obviously accelerate drying out. In these cases, the groomed area can become surprisingly dry, which should never happen.

Germination tip: The best way to germinate, if you ask us, is to pre-sprout in a glass of water. And fortunately, it’s quite a simple method. You put the seed in a glass of water (ideally demineralised/RO water) and place it in a dark place at room temperature or slightly warmer. This way there is no risk of the seed drying out.

Since the seed is completely surrounded by water, it penetrates the seed coat efficiently and evenly, and the germination process is accelerated. As soon as the radicle emerges, plant the seed in your preferred soil. Super simple and super effective.



If you have chosen to pregerminate in paper towels or a glass of water, be careful not to let the seed germinate too long. This is a typical error, which often occurs during pre-sprouting.

It is quite easy to see if the seed has germinated too long. If the radicle grows longer than 2 cm, or if it is completely grey and you start to see the small white cotyledons, these are clear indicators that it has sprouted too long.

This makes the subsequent transplant of the seed to a greenhouse difficult, as it is extremely easy to damage the delicate seedling during the operation itself.

The picture below is an example of seeds that have germinated too long.

Germinating cannabis seeds for long radicles
To avoid this, it is best to plant the seed before the radicle grows more than 1-2 cm long. This will make the process much easier, while ensuring that you don’t damage the seed’s development at an early stage, allowing it to get off to a strong start.


You may think that it seems easiest to germinate/sow your seeds directly in the soil. And it usually does, but it’s not a method we can recommend. Especially not if the soil is not moistened beforehand, but only watered afterwards.

The reason we don’t recommend this method is that you risk burying the seed too deeply, which only gets worse if you water after sowing. Watering can cause the seed to be pushed or buried deeper into the soil.

It is therefore a huge advantage to pre-sprout in a glass of water (read: our preferred method), kitchen roll, jiffy or rockwool brick, which is also used for cuttings/clones. The germination process is faster and there are fewer things that can go wrong. Once the seed has germinated, you can easily sow it in a pot.

Another advantage is that you can germinate a lot of seeds in a small area, which makes it much easier to maintain an environment with the right temperature and humidity.
Sowing cannabis seeds directly in soil


Temperature is a point you must not compromise on when you want a successful germination. For seeds to germinate properly, a relatively high temperature is required. But not too high.

Cannabis seeds germinate in temperatures between 21°C-32°C. Temperatures below 21°C inhibit the germination process, while temperatures higher than 32°C destroy the seed’s chemical process.

Ordinary room temperature or slightly warmer is therefore all that is needed. The ideal temperature for germination is 25-26°C, but room temperature is fine and will still provide good conditions for germination.

Room temperature cannabis seeds germination


Now we’ve talked a lot about moisture being important for successful germination. But there is a big difference between a humid environment and a wet environment.

The grout should be moist, but not definitely wet. If the seed is planted in a wet jiffy or pot without drainage, and it may be at a relatively high temperature, there is a risk of fungal infection, so the seed simply rots in the soil.

The gromite should only be slightly moist and never stand in water. Water must either be able to be absorbed quickly or be able to drain away again.

To maintain high humidity, many people use a greenhouse for sowing. Sometimes with a heating mat underneath. This is risky as humidity quickly rises above 80% and, combined with heat, creates a favourable environment for fungus and rot.

Using jiffys makes it easy to get the liquid out. Give it a firm squeeze by hand until it is only slightly damp. Then it’s perfect and ready for sowing your seeds.



Cannabis seeds have a slightly oval shape. The top of the seed is pointed and the other end, called the crown, is flat (see picture below).

When planting a seed, the pointed end should ideally face upwards, while the flat end – the crown – should face downwards towards the ground.

Cannabis seed germination seed design
If this doesn’t happen, the seedling spends energy “turning back” against gravity. If the seed is planted very close to the soil surface, there is also a risk that the radicle will break through and grow above the soil, almost certainly causing the seedling to die.

What’s more, the seed has to spend precious energy redirecting the germ root in the right direction – energy we’d rather see spent on something productive, like quickly establishing itself and setting the first set of leaves.

Because the seed is so small, it can be difficult to get it to turn properly in the groove. The seed root will search downwards by gravity, so it is often not a problem that the seed is not “theoretically correct” in the soil. However, there is a slight risk that the seed will become confused and the radicle will grow upwards. Therefore, it is a good idea to help the seed on its way already at sowing.

Sowing cannabis seeds



As we already mentioned in point 3, another frequent mistake is that the seed gets too deep into the soil. This may cause the seed never to emerge from the ground.

A good rule of thumb to remember the correct depth is that it should be planted about twice the height of the seed down in the soil (about 0.5-0.7 cm). Furthermore, the seed should be covered with loose green material so that it does not spend unnecessary effort penetrating the surface.



Several cannabis seeds in the same pot
It may be tempting to plant several seeds in the same pot, but this is not a very good idea for several reasons.

Firstly, it will cause plants to compete with each other for root space. Limited root space is not good for cannabis plants, and it results in weaker growth, greater spacing between stem joints and thus thinner plants.

Furthermore, it will mean that the plants shade each other. The plants will prefer to grow upwards (to get more light) rather than bush out to the sides. Growth will therefore be concentrated around a weak main stem with too long a distance between stem joints. This typically has a negative effect on returns in the end.


Some plants love light, others love shade. But what about cannabis seeds when they are to germinate?

In fact, cannabis seeds don’t need much light to germinate. On the contrary, too much light can damage seedlings in the first weeks. If seedlings receive too much light in the initial phase, they may over-stretch or burn off in over-lighting.

Therefore, it may be a good idea to use mild lighting suitable for seed germination – such as fluorescent lighting or a remote corner of the lawn.

Germinating cannabis seeds indoors or outdoors?

You probably know that it’s possible to grow cannabis indoors as well as outdoors, but is the same true for sprouting?

In principle, yes, but because germination is a relatively short process, we recommend that you do it indoors. Germinating your cannabis seeds indoors makes it easier to monitor temperature, light levels and the process itself, so you don’t risk your seeds over-sprouting.

When it’s time to plant your pre-pollinated seeds, you can decide whether to plant them outside or inside.

If you are interested in growing cannabis outdoors, you can read more here.

9 quick tips: how to succeed with your sprouting

Above, we’ve given our top picks for things that could be causing you to fail with your sprouting. We’ve described the different points in as much detail as possible, so you can really get to grips with germination, pre-sprouting and sowing to the gold standard.

However, we also know that not everyone is into nerdiness and long explanations. Others are more into quick, concrete facts. So that’s exactly what we’re giving you here, where you’ll get our top tips for successful sprouting in 9 quick points:

1. Moisture, moisture and more moisture: we recommend pre-sprouting in a glass of water.
2. Avoid too long germination by planting the seed before the radicle grows more than 1-2 cm long.
3. Avoid germinating directly in soil, as you risk burying the seed too deep.
4. The ideal temperature for germination is 25-26°C, but room temperature will also work fine.
5. Avoid a wet green area. It should be slightly damp, but never in water.
6. When planting a seed, the ‘pointed’ end of the seed should ideally face upwards, while the flat end should face downwards towards the ground.
7. The seed should be planted about twice the height of the seed down in the soil (about 0.5-0.7 cm) to ensure that it does not get too deep.
8. Avoid planting several seeds in the same pot, as the plants will compete with each other for root space and shade each other out.
9. Pay attention to light. Place the seed in the dark for the first 24 hours and then use mild lighting suitable for seed germination – such as fluorescent lighting.

See our large selection of cannabis seeds and skunk seeds here.

We hope this post can help you avoid problems with your sprouting. It can be extremely frustrating and feel like a wet rag on your face when your seeds don’t germinate or if they stall. However, by being aware of the above mistakes, there is a good chance that you will get off to a flying start.