How to Germinate Cannabis Seeds: A Step-by-Step Guide

Congratulations! You’ve taken the first step in your cannabis-growing journey by getting some weed seeds. But now what?

You’ll need to germinate them right to give your beloved plants the best start possible, and even a small misstep can affect your plant’s lifecycle.

In this article, we’ll share several common ways to germinate your seeds and other tips like feeding the right nutrients and watering techniques for your little baby seedlings.

How to Germinate Cannabis Seeds: Key Takeaways

Make sure you’re using viable cannabis seeds. Most dark seeds will germinate under good conditions, while pale green or white seeds will not.
Cannabis seeds need moisture, warmth (22–25°C or 71–77°F), and reduced handling for a better germination rate.
The best weed seed germination methods include paper towels, direct planting, water soaking, and germination kits.
Seeds typically start sprouting within 12–36 hours with the right conditions, depending on the germination method and the seed quality. Some can take a week.
Once sprouted, transplant the seed about a knuckle deep in the growing medium, with the white taproot facing downward and the top just below the surface.

Germinating cannabis seeds is more than simply sticking them in the soil and waiting for them to grow.

By the end of this blog post, you’ll have all you need to germinate your cannabis seeds and start them right!

Introduction to Cannabis Seed Germination

Cannabis seed sprouting a radicle.

Germination is the process of getting a seed to sprout a taproot, which eventually grows into the plant’s main root in the soil.

Before planting, carefully inspect your seeds. Healthy marijuana seeds are typically dark and firm to the touch, often with stripes or other markings.

To increase your chances of success, look for darker-coloured seeds that are more likely to germinate into healthy plants, eventually producing potent, flavourful buds!

Most weed seeds will sprout, but lower-quality seeds can lead to weaker plants. Unfortunately, you may not notice this until the plant is well into its vegetative stage, so be sure to get only top-quality seeds from a reputable source. (Like us at AussieHempSeeds!)

Overview of the Cannabis Seed Germination Process

Here are the main things that happen during the germination process.

Water absorption: When seeds come into contact with moisture, they absorb water.
Metabolic activation: As the seed takes in water, it activates enzymes and other important parts inside the seed. These enzymes begin breaking down stored nutrients.
Imbibition: As the seed absorbs more water, it swells and eventually causes its outer shell to break open.
Radicle emergence: After the outer shell breaks, the first tiny root, known as the radicle, emerges. This will grow into the main root of the plant.
Emergence of stem and leaves: The hypocotyl (the part of the stem below the first leaves), the cotyledon (the first leaves), and the epicotyl (the part of the stem above the first leaves) also emerge from the broken seed coat.

Now, here are all the best techniques for germinating cannabis seeds to give your precious plants the best start possible!

Best Methods for Germinating Cannabis Seeds

Based on years of helping people grow healthy marijuana plants at Aussie Hemp Seeds, we can confidently recommend four methods:

Paper towels, which is the most popular among our growing community.
Direct in soil
Water soaking
Germination kits

Below, you’ll find a step-by-step guide for each method, along with their pros and cons, to help you choose the best one.

METHOD 1: Paper Towel

Alt: Cannabis seeds sprouting radicle on a paper towel.

The most popular germination method is the paper towel method. Many growers use cotton wool pads or absorbent paper, but we prefer kitchen towels as they are easy to find and are excellent at retaining moisture.

Step 1: Place a damp kitchen towel on a flat surface.

Step 2: Space your seeds a few centimetres apart on the towel, then cover them with a second damp kitchen towel. Make sure both towels are moist but not soaking wet.

Step 3: Check the seeds every 12 hours, but avoid overhandling them or their roots.

Step 4: When the white root tips are 1-2 cm long, carefully transfer the seeds to soil pots with the taproot facing downward. You can plant sprouted seeds immediately or wait a day or two for any remaining seeds to catch up.

Quick Tip:

Use cheap paper towels. They work best because they are less porous, preventing seeds and roots from sticking. Avoid cloth-like paper towels, as their texture can cause roots to grow into them.

Pros of the Paper Towel Method	Cons of the Paper Towel Method
Common and widely used.	If not done correctly, seeds might become too fragile for successful transplanting.
Simple and beginner-friendly.
No special tools are required.

METHOD 2: Direct in Soil

Planting seeds directly into the growing medium helps avoid disturbing them when they are most delicate. The first root tip is covered with tiny filaments that are easily damaged, and sticking them directly in their growing medium reduces the risk of damage.

Step 1: Fill pots with high-quality soil and water the soil to be moist (not wet).

Step 2: Some growers add a root stimulator to the water. Make a hole about 10–15 mm deep in the soil for the seed.

Step 3: Remove seeds from their packet and place them into the pre-made holes.

Step 4: Gently cover the seeds with soil, but avoid packing them down too tightly. Compacted soil can hinder root growth and slow down plant development.

Step 5: Lightly spray the top of where you placed the seed (or add a few drops of water) so that your growing medium stays moist.

Step 6: Place your pots where the temperature is 17°C at night and 23°C during the day.

Step 7: After 4–10 days, you should see seedlings sprouting.

The baby seedlings, together with the soil in which they were started, can now be transferred to a larger pot.

Pros of Direct in Soil Method	Cons of Direct in Soil Method
Avoids shocking seedlings during transplanting.	Less control over the environment.

METHOD 3: Water Soaking

Soaking cannabis seeds in a glass of water.

Another method for germinating cannabis seeds is to soak them overnight in slightly warm water, ideally in a glass cup for better visuals.

Step 1: Fill a glass or bowl halfway with water at about 22°C (71°F).

Step 2: After 3–5 days, the seeds should start to open, and tiny white tips will appear.

Step 3: Once the roots are 1-2 cm long, carefully transfer the seeds from the water to prepared soil pots.

Step 4: Make small holes in the soil pots, about 10–15 mm deep, to place the germinated seeds into.

Step 5: After placing the seeds, position a fluorescent light 13–15 cm (5–6 inches) above them to promote growth.

Pros of the Water Soaking Method	Cons of the Water Soaking Method
Ideal for seeds with hard shells.	It requires careful handling to avoid damaging delicate roots.
Effective for reviving older seeds.
Easy for beginners.

Method 4: Using Germination Kits

Cannabis seeds sprout from germination kits.

For a greater chance of success, consider using a germination or starter kit. These kits typically include seedling pots, Bacto (a soil enhancer), perlite, fluorescent lights, and an instruction manual that typically will have these steps.

Step 1: Gently open the seed packet and place the seeds into a dry container.

Step 2: Fill a shallow container with one litre of lukewarm water (22–25°C/71–77°F).

Step 3: Add the Bacto enzyme and let it dissolve. Immerse the seed tray into the dry container for 5–10 seconds. Keep the Bacto mixture for future use.

Step 4: Remove the seed tray from the water and make a 10–15 mm deep hole in the soil of each pot. Gently place one seed into each hole—one seed for each pot.

Step 5: Add a 15-mm layer of perlite to the bottom of the tray using a propagator.

Step 6: Put the seed tray into the propagator, adjust the walls, and cover with the lid. However, not all starter kits will come with protective walls and lids for you to cover.

Step 7: Check the water level in the reservoir daily to keep it even. After 1–7 days, seeds should sprout, and you might see leaves.

Once the seedlings reach 3 cm tall, transfer them to their growing medium.

Pros of the Germination Kit Method	Cons of the Germination Kit Method
Easy to use.	Costs money
Includes a soil enhancer.
Provides an organic soil mixture with useful fungi.
Promotes healthy roots.

Choosing the Right Environment

Now you know how to germinate your cannabis seeds, we’ll now look into constructing the perfect environment for the little babies to grow.

Keeping seeds warm is the general rule of thumb, as seeds kept in a cool place can take longer to germinate.

The easiest way to achieve this is to use a grow light but place it higher to avoid drying out the soil or overwhelming the seedlings.

Alternatively, use a small reptile heat lamp, an incandescent lightbulb, or a heating pad from a garden store to provide warmth.

Ideally, during the germination phase, the temperature should be between 22° and 25°C (71–77°F), and the relative humidity should be between 70% and 90%.

Monitoring and Caring for Seeds During Germination

Another point to note is that cannabis seeds don’t need a lot of handling while they’re germinating.

Once you’ve set the right conditions for your chosen method, let nature do its thing. When you see that your seeds have sprouted, plant them immediately.

Try not to touch the tiny white root with your fingers. Instead, move the seeds carefully or use a pair of tweezers.

If you accidentally break the root, the seedling might still grow, but it will likely be slower and weaker from the start.

How Long Does It Take to Germinate Cannabis Seeds?

The germination process of a marijuana seed usually takes between 1 and 7 days from start to finish.

This is just an average, and the exact time can vary depending on the quality of the seeds, growing conditions, or method.

For instance, older or larger seeds in cooler temperatures can take over a week to germinate compared to fresh, viable seeds in warmth.

However, under the right temperature and proper conditions, one week is typically the maximum you’ll have to wait for your seeds to germinate.

Water and Nutrient Requirements

The most common issues with germinating cannabis seeds are usually related to watering and the germination method used. Overwatering or underwatering can both cause problems.

When a cannabis seed starts to germinate, a tiny white root will appear. If the seed is soaked for too long, this root can stop growing and begin to rot.

If directly planting or using a paper towel, be sure to keep the seed moist but not soaked so the new root doesn’t have to absorb too much water.

Nutrient Requirements During Germination

It’s better not to use fertilisers or additives during the first week of growth.

At this stage, your plants don’t need extra nutrients and can be harmed by too much fertiliser.

If you’re using high-quality potting soil like Happy Frog potting soil mix, you probably won’t need to add extra nutrients for the first week or two.

When growing in coco coir or hydroponics, begin by using cannabis plant nutrients at about a quarter of the regular amount.

Stick with this until your plants have a few sets of leaves, then you can gradually increase the nutrient strength to the full recommended amount.

Common Mistakes in Watering and Nutrient Application

New growers often forget that less is more for young seedlings, which cannot handle full-strength grow lights or nutrients.

Another mistake is using soil with pre-mixed nutrients, like Miracle Gro. This should only be done once the plants have developed a few sets of leaves.

In addition, don’t keep the grow lights too close to the seedlings in an attempt to provide warmth. Instead, keep the lights further away, about twice the usual distance, for the first few days.

After about two weeks, the seedlings can start being treated like they’re in the vegetative stage.

FAQs

What is the Best Way to Germinate Cannabis Seeds?

It depends on the seed, your expertise, and the available resources. But overall, we recommend the paper towel method as the best way to germinate cannabis seeds. It’s free, and it creates excellent conditions for seeds to germinate quickly.

Can I Germinate Old Seeds?

Yes, you can germinate old seeds, and the water-soaking method is the best germination approach because the technique can help soften the seed’s hard shells. However, before you germinate it, you have to be sure the old seed is viable and has not gone bad.

How Do I Know If My Seeds Are Viable?

A germination test is the best way to measure seed viability. However, good marijuana seeds are usually dark, firm to the touch, and marked. However, even weak-looking seeds can end up growing well.

Final Thoughts

Regardless of the germination method, it all starts with the right seed. If a seedling hasn’t sprouted in 10 days, it most likely won’t.

At Aussie Hemp Seeds, we’ve dedicated ourselves to providing top-quality seeds with a high germination rate. Check out our wide range of feminised and a utoflower cannabis seeds and start your growing journey with style!