autoflower seed germinated on black surface

Looking to transform tiny autoflower seeds into flourishing cannabis plants? You’re in the right place. In this comprehensive guide, we’re pulling back the lid on the process of germinating autoflower seeds – the essential first step towards a successful grow.

We will look into the ideal conditions, and foolproof methods to increase germination success rates, how to germinate older seeds and finally how to plant them. Ready to sow your seeds? Let’s get started.

What conditions are required for autoflower to germinate?

Understanding the necessary conditions for germinating autoflower seeds is crucial if you want high success rates. Autoflower seeds, like all cannabis seeds, require certain environmental factors to germinate. Here are the key factors that you must have in place to get your auto seeds to pop.


Temperature is key! A range of 20-25°C (68-77°F) creates the ideal warmth required to encourage germination. Any temperatures outside this range will reduce your chances of successful germination.


Secondly, moisture plays a key role. Seeds need consistent, but not excessive, hydration to sprout. Overwatering can lead to rot, while underwatering might prevent germination altogether. The amount of moisture required differs from method to method so we will talk more on this later in the article.


Finally, darkness is essential during the initial germination stage. Light exposure too early can interfere with the process, slowing down or stunting the seed’s development.

By meeting these conditions – correct temperature, adequate moisture, and darkness – you are one step closer to successful germination.

The best ways of germinating autoflowering seeds

There is no one correct way to germinate autoflower seeds, each has its own advantages and disadvantages. Let’s explore the four of best ways to germinate your seeds.

Germinating autoflower seeds using paper towels

The paper towel method is a simple and reliable way to germinate autoflower seeds. Here’s a step-by-step guide:

  1. Start by selecting a few sturdy paper towels and thoroughly moisten them with warm water. Avoid soaking; the towels should be damp, not dripping.
  2. Place your autoflower seeds on one half of the towel, ensuring they are spaced out to prevent them from sticking together.
  3. Fold the other half of the towel over the seeds, creating a damp enclosure.
  4. Gently place this package in a plastic bag or between two plates to maintain humidity and darkness.
  5. Store the setup in a warm place (20-25°C/68-77°F).
  6. Check your seeds daily for moisture and signs of a sprouting taproot. If the towel dries out, sprinkle it with some water. Be careful not to oversaturate it.
  7. Once the taproot appears (usually in 24-72 hours), the seeds are ready to be carefully transferred to their growing medium.

Germinating autoflower seeds in rockwool or peat pellets

Germinating autoflower seeds in rockwool or peat pellets is another effective method, offering the advantage of minimal handling of the seedlings. Here’s how to do it:

  1. Start by soaking your rockwool cubes or peat pellets in distilled water with a pH of about 5.5 for an hour. This ensures the medium is perfectly moist and pH-balanced.
  2. Using sterilized tweezers, gently place one autoflower seed into the hole of each cube or pellet. The seed should be about a quarter-inch deep.
  3. Cover the hole lightly. If using rockwool, you can pinch the material over the seed. If you’re using peat pellets, a small pinch of peat moss over the hole will suffice.
  4. Place the cubes or pellets in a tray with a dome cover to maintain humidity. Keep the tray in a warm, dark area, maintaining an ambient temperature of 20-25°C (68-77°F).
  5. Keep an eye on the moisture levels. If the cubes or pellets feel dry to the touch, mist them lightly with water.
  6. After a few days, you should see a sprout emerging from the pellet or cube. At this stage, you can introduce the seedling to a light source to support its growth.
  7. Once the roots start to emerge from the cube or pellet, it’s time to transplant your seedling into its final growing medium.

This method is particularly favorable due to its simplicity and the ease of transplanting the germinated seeds.

Soaking autoflower seeds in water

Soaking autoflower seeds in water is one of the quickest germination methods, typically showing results within 24-48 hours. Here’s a simple guide to this technique:

  1. Fill a glass or jar with room temperature water (not too cold, not too hot). The water should be chlorine-free, so either use distilled water or allow tap water to sit out for 24 hours to dissipate any chlorine.
  2. Gently drop your autoflower seeds into the water. Initially, they might float, but they should sink to the bottom within a few hours.
  3. Place the glass in a warm, dark place. The ideal temperature is between 20-25°C (68-77°F).
  4. Check your seeds every 12 hours. You’re looking for a small white taproot beginning to emerge.
  5. Once the taproot appears (usually within 24-48 hours), it’s time to carefully move the germinated seed into its growing medium. It’s important not to leave the seeds in water for more than 72 hours, as they may drown.

How do you germinate Autoflower seeds directly in soil?

Germinating autoflower seeds directly in soil is a natural method that minimizes the risk of damaging the delicate taproot. Here’s how to proceed:

  1. Start with a high-quality potting soil. It should be light and airy to allow the roots to breathe and grow easily.
  2. Moisten the soil with water until it’s damp but not waterlogged. The soil should form a clump if you squeeze it in your hand, but it should not drip water.
  3. Make a small hole in the soil, about 0.5-1 cm deep. Gently place the autoflower seed in the hole, pointy end down.
  4. Cover the seed with soil lightly. Do not press or compact the soil as this may make it difficult for the seed to break through.
  5. Maintain a warm, humid environment for your seeds, ideally 20-25°C (68-77°F), and ensure the soil remains consistently moist.
  6. In about 5-10 days, you should see your seedlings break through the soil surface.
  7. Once your seedlings have established their first pair of true leaves, you can begin a gentle watering schedule.

This method is simple and requires less handling, making it suitable for beginners. Keep in mind that germinating autoflower seeds directly in soil might take a bit longer compared to other methods.

Tips to improve autoflower germination

If you want to increase your chances of successful autoflower seed germination, consider these expert tips:

  1. Quality of Seeds: Always start with high-quality seeds from a reputable source. Healthy, mature seeds have a better germination rate.
  2. Correct Storage: Store your seeds in a cool, dark, and dry place before you’re ready to germinate them. Improper storage can reduce their viability.
  3. Check Moisture Levels: Whether you’re using a paper towel, soaking in water, or germinating in soil, maintaining the right moisture level is crucial. Too much can cause rot, too little can prevent germination.
  4. Ideal Temperature: Keep the environment at a consistent 20-25°C (68-77°F). A heat mat can help maintain the right temperature.
  5. Gentle Handling: When transferring germinated seeds, handle them delicately to avoid damaging the taproot. Tweezers can be helpful.
  6. Early Light: Once the seedlings have sprouted, provide them with 14-18 hours of light per day to encourage robust growth.
  7. Proper Nutrition: Once sprouted, your seedlings will need a gentle, balanced nutrient solution to thrive.

With these tips at your disposal, you’re well-equipped to optimize the germination process for your autoflower seeds.

Scarify older seeds

Older seeds may require an additional step before germination: scarification. Scarification is the process of gently weakening the seed’s outer shell to make it easier for water to penetrate and for the taproot to break out. This method can improve the germination rate of older or tougher seeds. Here’s how to do it:

What tools are needed? You’ll need a small file, sandpaper, or a seed scarifier. If none of these are available, a small nail clipper can work too.

  1. Carefully, without applying too much pressure, rub the seed between the file or sandpaper a few times. You can also use the nail clipper to gently chip a tiny piece of the shell. The goal is to thin the shell, not break it.
  2. If you’re using a seed scarifier, simply place the seed inside and gently close the scarifier until it nicks the seed shell.
  3. After scarification, proceed with your preferred method of germination.

Please note that this method should be done gently and with caution. Excessive force can damage the seed’s internals, making it impossible to germinate. For autoflower seeds, scarification should only be a consideration if the seeds are older or have particularly hard shells.

Plant your autoflower seeds the right way up

planting a germinated autoflower seed direct into soil in a pot

While seeds will naturally orient themselves upwards, planting your autoflower seeds the right way up can give them a helpful start. The seed has a pointed end and a rounded end. The pointed end, where the taproot emerges, should be facing down.

When planting your seeds direct into soil or planting in rockwool or peat pellets, gently place your autoflower seed in the hole you’ve created with the pointed end down. Cover it lightly with soil or the medium, and maintain the correct moisture and temperature conditions.

Remember, the seed is a living organism that knows which way to grow. Even if you accidentally plant a seed the wrong way, it will usually correct its course. However, ensuring the right orientation from the start can save the young plant some energy and potentially speed up the germination process.

Plant your autoflower seeds at the right depth

Planting depth plays a critical role in the successful germination of your autoflower seeds. The general rule of thumb is to plant the seed two times deeper than its width. For most autoflower seeds, this means a depth of approximately 0.5-1 cm (0.2-0.4 inches).

Planting too shallow may expose the seed to light too early or cause it to dry out. On the other hand, planting too deep can make it harder for the seedling to break through the surface and can delay or even prevent germination.

Don’t let the soil dry out

Keeping the soil appropriately moist is a major factor in successful germination and where many novices go wrong. Seeds need constant access to water to activate the germination process and support the young seedling’s growth.

  1. After sowing your seeds, ensure the soil or growing medium is damp, but not waterlogged. Overwatering can cause the seeds to rot or develop fungal issues.
  2. Keep the soil consistently moist throughout the germination phase. If the surface feels dry to the touch, mist it gently with a spray bottle. Remember, the goal is to keep the soil damp, not soaking.
  3. Consider using a humidity dome or a simple plastic bag to cover the pot and maintain high humidity, especially in arid climates or heated indoor environments.
  4. As the seedlings emerge, continue to keep the soil moist, gradually reducing the humidity as they grow and develop their first true leaves.

Remember, water is life for your seeds, but balance is key. By keeping the soil properly moist, but not overly wet you are creating the optimal environment for your autoflower seeds to germinate and grow.

How long does it take autoflower seeds to germinate?

Typically, autoflower seeds begin to germinate within 24-48 hours and fully sprout in 3-7 days when optimal conditions are provided. However, the germination time can vary depending on the quality of the seed, the method of germination and the environmental conditions.

Here’s a rough timeline for each germination method:

  1. Paper Towel Method: Taproot usually emerges within 24-72 hours.
  2. Directly in Soil: Seedlings generally break through the soil surface in 5-10 days.
  3. Water Soaking: Taproot often appears within 24-48 hours.
  4. Rockwool or Peat Pellets: Seedlings typically sprout in 3-7 days.

Remember, these timelines are estimates. Some seeds might take a little longer, and that’s okay. If a seed hasn’t germinated after 14 days, it’s likely that it won’t and you may need to start with a new seed.

Do Autoflowers need light to sprout?

No, autoflower seeds don’t require light to germinate, however, once they have used up all of the energy inside the seed and broken through the surface of the soil, their leaves take over in providing energy for growth. At this point the plant is in the seedling stage and requires light. Here’s a quick breakdown of the process:

  1. Germination Stage: Autoflower seeds can germinate in complete darkness. In fact, the absence of light can help mimic the natural environment, where seeds are buried in the soil, away from direct light.
  2. Post-Germination: As soon as the seedling breaks the surface of the soil, it needs light. Light acts as a trigger for photosynthesis, the process by which plants convert light into energy for growth.
  3. Seedling Stage: Seedlings require a significant amount of light – 14 to 18 hours per day is often recommended. This light schedule should continue throughout the plant’s lifecycle due to the autoflowering nature of these strains.

What soil is best for germinating Autoflowers?

If you are germinating direct to soil, getting the right soil is crucial. Autoflowers prefer a light, well-aerated soil mix with good drainage. Here are key characteristics to consider:

  1. Lightness and Aeration: The soil should be light and airy to let roots breathe and grow without obstruction. A soil mix with perlite, vermiculite, or coco coir can provide this structure.
  2. Drainage: Good drainage is essential to prevent waterlogging and root rot. Again, ingredients like perlite or vermiculite help improve soil drainage.
  3. pH Level: Cannabis plants prefer slightly acidic soil, with a pH between 6.0 and 7.0. The correct pH ensures the plants can uptake necessary nutrients.
  4. Nutrient Content: Start with a light nutrient mix, as autoflower seedlings are sensitive to over-fertilization. Later, as your plants grow, you can introduce a nutrient schedule to meet their needs.
  5. Organic Matter: A soil rich in organic matter can provide nutrients and beneficial microorganisms that help plants grow. Compost, worm castings, or bat guano can enhance the soil’s organic content.

You can find commercial soil mixes designed for cannabis growth or create your own blend. When it comes to germinating autoflower seeds, less is more. It’s easier to add nutrients later than to remedy a problem caused by over-fertilization in the early stages.

What is the best temperature for autoflower germination?

The ideal temperature for autoflower seed germination is between 20-25°C (68-77°F). This range closely mimics the spring and early summer conditions that naturally encourage cannabis seeds to sprout.

A stable and suitable temperature is essential for the activation of enzymes that kick-start the germination process. Temperatures below this range can slow down germination or stop it altogether, while temperatures above this range can cause damage to the seeds.

Maintaining the right temperature can be achieved using a heat mat or by placing the seeds in a warm location in your home. After germination, maintaining a similar temperature range for the seedlings can help ensure robust growth.

How long is the seedling stage for Autoflowers?

The seedling stage for autoflowering strains typically lasts between 1 to 3 weeks from the moment they sprout. During this stage, the seedlings develop their first proper sets of leaves. After 1-3 weeks the seedling stage ends when the plant begins to develop leaves with serrated edges and the full characteristic number of leaflets. Most cannabis plants produce leaves with 5-7 leaflets.

Autoflowers have a different lifecycle compared to regular photoperiod plants. They transition from the seedling stage to the vegetative stage quickly and then start flowering automatically, usually a few weeks after germination, regardless of the light cycle.


Successfully growing autoflowers begins with correct germination methods. Hopefully you now understand how to provide ideal conditions for autoflower seeds, the best germination methods, and pro tips to boost your success rate. Apply this knowledge to your next autoflower grow and your germination rates should drastically increase. If you’ve found this guide useful, don’t forget to like and share this article! Enjoy growing!

Joe Musgrave

An avid 420 enthusiast, grower, smoker and writer. Joe writes non stop, sharing his extensive knowledge in the field of cannabis with the wider online 420 community through blogs like ours at High Yield Strains.

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