How to Germinate Cannabis Seeds

How to Germinate Cannabis Seeds: Best Way to Germinate Seeds for an Indoor Grow

Today I am going to cover how to germinate cannabis seeds successfully for your next indoor grow. I have grown cannabis for decades and still use the same simple germination methods that I used years ago. I will teach you exactly how to do it, what to look out for, how to pick the right seeds and much more.

How to Germinate Cannabis Seeds
Cannabis seeds germinating

What Exactly Is Germination?

Before we delve into the details, it’s crucial to understand what seed germination is. In the simplest terms, germination is the process in which a new plant begins to grow from a seed. When you think about how seeds germinate, imagine a seed like a tiny package carrying the genetic blueprint of a plant. It remains inactive until the right environmental conditions trigger its growth, resulting in a sprouting seedling.

It is important to note that there is potential for genetic differences in seeds. Meaning that each seed will grow a slightly different and unique plant. That is one of the reasons why a lot of growers prefer to start from clones instead. Clones are all pieces of the same mother plant and therefore have identical genes.

Types of Cannabis Seeds

Cannabis seeds come in a variety of forms, each with its own unique set of characteristics. Let’s briefly explore these types before we move on to the germination process.

Each of the seed types below can also be divided into type-1, 2, 3 and 4 which are commonly found in seed banks.

  • Type 1 — Regular high-THC cannabis
  • Type 2 — 1:1 THC to CBD ratio
  • Type 3 — High-CBD with low THC
  • Type 4 — Cannabis that is high is CBG or other cannabinoids

Autoflowering Seeds

These seeds automatically switch from the vegetative phase to the flowering phase without relying on a change in the light cycle, making them an excellent choice for beginner growers.

Under normal conditions, you (as the grower) would need to switch the light cycle to a longer dark period in order to trigger your plants to go into flowering. You also want to switch to bloom nutrients at this point.

Photoperiod Seeds

Unlike autoflowering seeds, photoperiod seeds need specific light exposure to transition from the vegetative stage to the flowering stage.12 hours of darkness to induce flowering stage of the life cycle. They require more care, but they also offer higher yields.

Feminized Seeds

Feminized cannabis seeds are bred to eliminate male chromosomes, ensuring nearly 100% female plants. They save growers the hassle of identifying and removing male plants, which can pollinate and ruin your entire crop. You normally have around 1% chance of male plants from feminized seeds so keep an eye out and know what to look for when “sexing” plants at week 2 of the 12-12 light “flip.

Regular Cannabis Seeds

As nature intended, these regular seeds produce both male and female plants. This type of seed can be beneficial for breeders, but novice growers may prefer feminized or autoflowering seeds for simplicity.

How to Germinate Cannabis Seeds using the Paper Towel Method

The paper towel method is a popular and easy germination method for getting seeds to germinate in a moist paper towel. Here’s a step-by-step guide on how to germinate weed seeds using this method:

  1. Preparation — Take four paper towels and thoroughly wet them with distilled water. The pH of the water should be close to neutral. Aim for a best pH level for seed germination between 5.5 and 6.5. Use Amplify microbes in the initial soaking water to best results.
  2. Placement — Place two of the wet paper towels on a plate. Put your cannabis seeds on them, spaced about an inch apart. Cover the seeds with the remaining two paper towels.or put into a tied plastic vegetable bag instead of plates. World’s tiniest cheapest greenhouses
  3. Moisture and Warmth — Cover the plate with another to create a dome that maintains moisture and warmth. The temperature should ideally be between 70-85°F (21-29°C). For detailed information, refer to the cannabis seed germination temperature chart.
  4. Monitoring and Planting — Monitor your seeds daily for signs of germination. Once the taproot appears, it’s time to plant your sprouted seed.

When it comes to which way do you plant a germinated seed, the taproot (the tiny white protrusion) should be facing down. You can now move on to planting germinated seeds into the soil or any growing medium you prefer.

Germinate Cannabis Seeds with paper towel method
Germinating Cannabis Seeds using the Paper Towel Method

Start Your Marijuana Seeds Indoors

Indoor growing allows you to control the growing environment from A-Z, ensuring optimal conditions for your plants from day one. Start by preparing a space where you can maintain light, temperature, humidity and airflow.

*Germinating seeds for hydroponics is an advanced technique where plants are grown without soil, often in water-based nutrient solutions. This method can offer higher yields and faster growth, making it the a great way to grow. Just ensure that you start with the best nutrient mixes like those available at Organitek.

Plant Your Germinated Cannabis Seeds in Rockwool Cubes

Rockwool offer an effective, straightforward way to nurture your seedlings. Once your seed has sprouted, simply insert the germinated seed into the pellet with the root facing downwards. Follow our guide on how to use rockwool here.

How to Use Rockwool in Hydroponics
Keep the sprouts clearly marked and organized in rockwool cubes

Tips Before You Start Germinating Weed Seeds

To maximize the success of your germination process, keep the following tips in mind:

  • Use fresh seeds — The fresher the seeds, the higher the germination rate. If you only have older seeds, you can use kelp to help inspire germination.
  • Control temperature and humidity — Both of these factors greatly impact seed germination. Too cool or too warm temperatures hurt the germination of cannabis seeds.
  • Avoid touching the taproot — The taproot is delicate, and any damage to it can hinder growth. Avoid touching it as much as possible.
  • Hydrate with care — Seeds need water to germinate, but excess water can lead to rotting so keep moisture but don’t over-do it.

What about growing from clones instead of seeds?

Growing from clones instead of seeds is a great way to speed up the growing process, save money and get healthier, more consistent plants. You can learn how to make cannabis clones

Germinating cannabis seeds might seem like a daunting process initially, but with a little patience, the right knowledge, and the best nutrients, you can transform your tiny seeds into bountiful cannabis plants. Happy growing!


By this point, you’re probably brimming with questions. Allow us to clear up some of the most frequently asked queries about germinating cannabis seeds.

Do I Need Growing Lights to Germinate Cannabis Seeds?

How do you germinate a seed without growing lights? Well, cannabis seeds don’t initially need light to germinate. However, as soon as they sprout, they will need a light source. Beginners can start with simple fluorescent lights, but as your plants grow, you may want to invest in high-intensity discharge (HID) lights or LED grow lights.

How Long Does it Take Pot Seeds to Sprout?

Patience is a virtue when you’re waiting for your seeds to sprout. Usually, cannabis seeds take between 24-120 hours (1-5 days) to sprout. But don’t panic if nothing happens right away. Some seeds take a bit longer.

How Much Light Do the Seeds Need After Being Planted, and for How Long?

After planting, your seedlings will need about 16-20 hours of light per day for the first 4-6 weeks. The length of time needed in veg is related to how much space you have available to flower in. Remember, gentle is key here. Start with softer, cooler lights to avoid burning the plants.

How Do I Stop Seedlings From Shooting up Too Long and Thin?

Leggy seedlings are often a sign of insufficient light. Ensure your seedlings have enough light exposure and consider using a fan for gentle air movement, which can help promote sturdier growth.

When Do I Start the Light Cycle?

The light cycle should start as soon as your seed has sprouted. The sprouting seedling needs lots of light to develop into a healthy plant.

Should I Remove the Seed Shell from the Seedling?

Typically, the seed shell falls off naturally. If it doesn’t, you can carefully remove it using a pair of tweezers, but be extremely gentle to avoid damaging the seedling.

What is the Best Temperature to Germinate Cannabis Seeds?

The ideal temperature for cannabis seed germination is between 70-85°F (21-29°C). Keep your seeds in a warm place to encourage sprouting. Consider investing in a heat mat if you live in a cold area or germinate during winter.

When is the Best Time of the Year to Germinate Cannabis Seeds?

For indoor growing, any time of the year is suitable as you control the environment. However, if you plan to transplant outdoors, start germination 8-10 weeks before the last expected frost. Plants will continue to grow outside until the light cycle gets to 12 hrs light and 1 hours darkness.

My Cannabis Seeds Won’t Sprout After a Few Days, Why?

Several factors might hinder your seeds from sprouting. These can include old or poor-quality seeds, improper storage, or unfavorable germination conditions. Always source your seeds from reliable suppliers and follow the best germination practices. Kelp and Amplify can help with your success rate!

How to Store Cannabis Seeds?

Store your cannabis seeds in a cool, dark, and dry place. A refrigerator can work well for this. Use an airtight container to protect them from moisture and fluctuating temperatures.

How Do I Determine Seed Quality?

Good quality cannabis seeds are usually dark brown with a glossy finish. Avoid pale or green seeds as they’re likely immature. High-quality seeds also feel firm to the touch and won’t crush under slight pressure.

Cannabis Grow Series

This article is part of the cannabis grow series where we want to teach you how to grow cannabis step-by-step in a simple and effective way. Explore the full series here!

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