How To Germinate Cannabis Seeds

The moment the seed knows it is time to open up is when it gets moist. Using clean water for those very first moments of its life is crucial, as the seedling is extremely fragile and sensitive.

How To Germinate Cannabis Seeds

There are several ways you can germinate cannabis seeds. Some of these methods, however, are a bit risky, so we recommend going an alternative route. In this guide, we’ll discuss our favourite way to germinate seeds, before exploring some of the less-reliable methods. We’ll also review the process of transplanting freshly germinated seeds.

Our Recommendation: Germinating Cannabis Seeds Directly In The Medium

Germinating Cannabis Seeds Directly In The Medium

For some reason, cannabis cultivators tend to make seed germination unnecessarily complicated, and also somewhat risky. Maybe you’ve already heard about germinating seeds with moist paper towels or by tossing them in a glass of water—we will cover these methods below; however, we believe the easiest and best way to go about getting your seeds to sprout is to germinate them directly in the growing medium.

Simply put the seed about 0,5cm deep into the soil and cover the seed lightly. Keep an eye on the environment and keep it warm and humid - 20°C is the ideal temperature. Keep soil moist, but don't saturate it - waterlogged soil can do more harm than good. You can place a lamp above the seed to provide the adequate temperature for germination. Your precious cannabis seed will happily sprout within a few days!

Take note that your seeds do not need any nutrients, at least for the first two weeks of growth. New growers often make the mistake thinking they are helping by adding nutrients in this early phase of growth. DON'T! The seed contains everything it needs to grow for a couple of weeks. Adding additional feed runs the risk of burning the seedling out before it has had the chance to even begin growing. Feeding your seedling with plain water ensures that it will grow strong roots. If you really want, you can use a root stimulator although it isn’t absolutely required.

We’ve found that germinating directly in the medium isn’t just the easiest and most reliable way; it’s also the safest method for your seeds. Other techniques require transferring your recently sprouted seeds to a pot, so there’s a risk that the sensitive taproots can get damaged in transition. Other methods run the risk of seed rot. What’s more, we haven’t really found any advantages to using these methods over germinating seeds directly in the medium.

Use Germination Kits To Give Your Seeds A Head Start

To make it even easier to germinate your seeds, we recommend using a germination kit like the Zamnesia Smart Start or the Plagron Seedbox. These kits come with everything you need to give your seeds the best start possible.

The Smart Start by Zamnesia comes with 20 tiny pots already filled with compost. Even better, the Smart Start includes a special Stimulator Mix that will benefit germination by activating the microbiological life in your soil. All you need to do is moisten the Smart Start pots with water where you have dissolved the Stimulator Mix, then place a seed into each pot and cover with soil. Place the tray in a location at room temperature, and make sure the soil stays moist (don’t overwater). Your seeds will germinate in a few days. It’s recommended to use the Smart Start kit alongside a propagator to create the ideal environment for seedlings to develop.

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The Plagron Seedbox Germination Kit consists of a tray of 12 germination pellets and a snug-fitting transparent lid. It’s like a miniature greenhouse, so it’s the perfect environment for your seeds to sprout! The Plagron Seedbox also includes a bottle of Plagron Seedbooster, so you can give your cannabis plants-to-be a great head start. Moisten the tray of germination pellets with water and the Seedbooster; wait about five minutes for the water to absorb. Put your seeds in the holes, and fit the lid on the tray. Place the tray in a room at 20–24°C, and your seeds will sprout in 1–5 days.

Plagron Seedbox

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Other, Less Reliable Methods

Aside from germinating your cannabis seeds right in your growing medium, there are other, less reliable methods.

Paper Towel Method

Germinating Cannabis Seeds With Paper Towel Method

Our first on the list of not-so-reliable germination methods is the popular “paper towel method”. This involves placing your seeds between sheets of moist paper towel. You then cover the towel and seeds with two plates (or another suitable container like a lunchbox) to prevent undue light exposure, and store it in a warm and dark place. Check on the towels occasionally; if they’ve become dry, give them a little spritz with water. Your seeds should germinate in a few days.

Why we don’t recommend this method: It requires you to excessively handle your germinated seeds as you move them from the towels to their first growing container. For the sensitive taproots, this is anything but optimal. Issues can easily arise (like the roots sticking to the paper), which can easily damage your seeds. Furthermore, the paper can also get too wet, causing your seeds to suffocate or rot.

Glass Of Water

Germinating Cannabis Seeds In A Glass Of Water

Another popular germination method is to plop your seeds in a glass of water. This one seems easy, as you just drop your beans in and wait for taproots to appear.

Like the paper towel method, the main issue with the glass of water approach is that it’s just unnecessary. Between the excessive exposure to water and the handling involved in transplanting, you once again put your seeds at risk of suffocating or becoming damaged. That said, some growers use this method to get a quicker visual on whether their seeds are viable. If you are sure of the quality of your seeds, and have sourced them from a reputable seedbank, you shouldn’t need to go this route.


Germinating Cannabis Seeds in Rockwool

Germinating in rockwool is, in principle, a good way to get your seeds started, although it is more involved than other methods. You place your seeds in a rockwool cube, then put the moistened cubes in a tray or propagator while you wait for your seeds to sprout.

We do like that, unlike other methods, the rockwool protects the young seedlings so you can transplant them safely to larger pots. On the other hand, rockwool requires being soaked in water with a low pH before seeds can be added. Furthermore, rockwool cubes can dry out very fast, which is why we suggest this method for experienced cultivators only.

Peat Moss (Peat Pellets)

Germinating Cannabis Seeds in Peat Moss (Peat Pellets)

Germinating in peat moss pellets (Jiffy Pots) is actually a pretty decent way to get your seeds started. These pellets have the shape of a large pill; moisten them, and the pellets will grow into a larger shape held together by dissoluble netting. Poke a hole into the peat on top and place your seeds into them.

After our preferred method of directly germinating in your medium, peat pellets would be our next-best choice for germination.

What we do not like about peat pellets: The netting around the pellets isn’t always guaranteed to dissolve when you transfer them to a bigger pot. If this happens, the net can trap the roots of your plants so they can’t expand. Because of that, it is recommended that you remove the netting before transplanting, but doing so could possibly damage the sensitive roots of your seedling.

Coffee Filter

Germinating Cannabis Seeds Between Coffee Filters

Germinating with coffee filters is essentially the same as the paper towel method. You place your seeds between two or more sheets of coffee filters, moisten the sheets, then place them in a bag or container that you seal up.

Like the paper towel method, we don’t really recommend this needlessly complicated way of germinating your seeds. The risk of rot or damaging your seeds with tweezers when transplanting just isn’t worth it.

Transplanting Germinated Cannabis Seeds

Transplanting Germinated Cannabis Seeds

If you start your seeds with our recommended germination method (directly in the medium), you will eventually need to transplant your seedlings.

This promotes healthy plant growth, makes watering and feeding easier, and will benefit your yield. If a seedling is too leggy and fragile to transplant as is, you can cover more of it up with soil to stabilise and strengthen it in its new pot.

You can find out more about transplanting your seedlings by checking out our blog When And How To Transplant Cannabis Plants For Bigger Yields.

Now that you know how to germinate, you can move on to the full seedling phase and beyond!