The complete guide to germinating cannabis seeds
Before you can be met with bountiful hauls of dank buds, there are several stages of cannabis growing that take precedence. Unless you can successfully germinate cannabis seeds, you won’t have a plant to harvest. Give your seeds the best possible start in life by reading our definitive guide to germination.
THE ART OF GERMINATING CANNABIS SEEDS
Often overlooked, it is all too easy to assume that the vegetative and flowering stages of cannabis growth are the most critical parts of the plant’s life cycle. However, with the chance of failure high unless you know what you’re doing, poor planning when it comes to germination can make or break your next grow. Giving your cannabis seeds the best possible start on their journey to bulging buds is a surefire way to encourage a healthy and robust plant.
Small, fragile, and in desperate need of a helping hand, there are several ways you can germinate your cannabis seeds. All methods have varying degrees of success, with both advantages and disadvantages. It is important to note that even with advanced growing expertise and top-of-the-line equipment, you may still end up with a few failed seeds. This is a natural part of dealing with a living organism. At Royal Queen seeds, we only sell feminized cannabis seeds, so there is no need to worry about removing male plants.
WHAT TO LOOK OUT FOR IN CANNABIS SEEDS
Regardless of where you get your seeds from, it is best to give them a slight (and delicate) inspection before planting. Most of the time, all seeds will germinate; however, poor-quality seeds will produce a weaker plant. Unfortunately, that is something you will not find out until well into the vegetative and flowering stages.
To avoid disappointment, seeds that have a darker colouration stand a better chance of germinating, while pale green or white seeds are likely to fail. Even if dark seeds look slightly damaged, they should be planted anyway. There is a good chance they will still germinate, even if the outer shell is somewhat crushed.
GERMINATION TEMPERATURE PLAYS A CRUCIAL ROLE
Before we jump straight into the germination methods, there are a couple of germination golden rules. For the best results, we recommend staying within these guidelines, no matter how you choose to germinate. That being said, of all the factors to consider, temperature is one of the most critical. Seeds will always seek out even the smallest amount of moisture, but they use temperature as a sign that they need to do so.
• The ideal temperature is between 22° and 25°C (71–77°F)
• Your growing environment should be damp/moist, but never wet
• Relative humidity range should be between 70% and 90%
• Seeds favour fluorescent lighting (Cool White code 33)
• Minimise the amount of seed handling you do
• In hydroponic/rockwool plugs, the ideal PH value is 5.8–6.2
WHAT IS AN EXPECTED GERMINATION TIME?
Three fundamental principles will trigger that first small taproot to appear: warmth, moisture, and darkness. With the promise of moisture, a single root will take shape before slowly developing into the cannabis plant we know and love. In the right conditions, seeds will begin to develop within 12–36 hours of moisture being introduced to them.
Timescales can vary, as it all depends on how ideal your germination environment is (see the golden rules above). Even the worst grower could make a seed germinate, but it may take a few weeks and, of course, increases the risk of a weaker plant.
CHOOSING YOUR GERMINATION METHOD
GLASS OF WATER APPROACH
Arguably one of the least effective methods, but it is still viable. Incredibly simple to facilitate, beginner growers may opt to germinate their seeds in a glass of water. Half-fill a glass or bowl with water that is approximately 22°C (71°F).
After 3–5 days, the seeds will start to open, and you should see tiny white tips appear. Once these roots reach 2–3mm in length, use extreme care to transfer them from the water to pre-prepared soil pots.
The soil pots will need small holes (roughly 10–15mm deep) for the newly germinated seeds to be placed into. Once the seeds are secure, you will want to place a fluorescent light 13–15cm (5–6 inches) away to encourage growth. Finally, don’t risk overwatering your seeds at this early stage. Use a plant mister to make sure they stay damp but not soaking wet.
WET KITCHEN TOWEL METHOD
Probably one of the most common methods of germination. The kitchen towel method comes in several iterations. Some growers use cotton wool pads or absorbent pieces of paper. For this guide, we will be using kitchen towel as it is readily available and holds moisture relatively well.
Place one sheet of damp kitchen towel on a flat surface. Space your seeds a few centimetres apart before placing the second piece of kitchen towel over the top. You need to ensure both pieces are damp, not wet. Once again, when the white root tips reach 2–3mm, move the seeds (carefully) to soil pots. Use the same guidance found above for planting techniques.
PLANTING DIRECTLY INTO SOIL
Planting directly into your growing medium prevents having to move seeds when they are at their most fragile. That first root tip is covered with microscopic filaments that are easily damaged. Given that both a cup full of water and moist paper towels are more prone to temperature fluctuations from their environment, planting in soil is a much safer option.
Start by filling pots with a premium-quality soil that has been soaked in water. Many growers also choose to lace the water with a root stimulator. Make a hole roughly 10–15mm deep. This will be your seed’s new home. Remove the seeds from their packet and place them into the pre-dug holes. Loosely cover the seeds, but be careful not to compress the soil above the seed too much. The root will struggle to penetrate solid soil, slowing plant growth. Lightly spray the top of where you placed the seed so that your growing medium stays moist.
If you don’t like the idea of pre-soaking your soil, you can use a spray to moisten the holes before you plant each seed. With enough moisture surrounding your seeds, you can still encourage a root to develop.
Your growing pots will need to be placed in a damp climate that is within the temperature range listed under our golden rules. After 4–10 days, you should see a young seedling sprout, while the roots will have begun to develop underneath the soil. The entire plant and its soil can now be transferred to a larger pot, where normal growing routines should start.
USING STONE WOOL BLOCKS
Maintaining the ideal temperature (between 22–25°C/71–77°F) and moisture for germination is tricky. Leaving seeds out in the open environment or on a windowsill is far from ideal; a DIY climate-controlled cupboard would do a much better service. A warming mat is perfect for maintaining a constant temperature, but it doesn’t tackle the issue of moisture.
You will need to invest in a few pieces of unique equipment, but by using stone wool blocks, you can create a perfect utopia for germinating cannabis seeds. Soak the stone wool blocks in the same way you would a soil medium. The wool will retain the moisture and prevent the need to water during the early stages of germination. After the wool blocks are soaked, stick them in a plastic tray that also has a lid. Large cake tubs are ideal.
The dome of the plastic container will create your seeds’ own mini tropical climate. If you then place all the components in a temperature-controlled cupboard, you will have created a self-perpetuating supply of moisture—no need to touch the seeds again until they are ready to be transferred to your final growing medium as a young seedling. Using the stone wool block method, your seeds should germinate in one to two days.
Two or three weeks after germination, your young seedlings should be ready for their new home. At this point you have two options; transplanting them into soil pots, or taking on the challenge of hydroponics. You’ll know when the seedlings are ready to be moved because the root system should start to poke out of the bottom of the wool blocks. As long as the roots haven’t begun to engulf the bottom half of the wool block, they will seek out water and nutrients in their new surroundings and continue to grow downwards.
ROYAL QUEEN SEEDS FEMINIZED STARTER KIT
There is, of course, a far simpler way to germinate seeds. Ideal for beginners, the feminized starter kit by Royal Queen Seeds has everything you need to kick-start your next cannabis project.
The Royal Queen Seeds Feminized Starter Kit contains:
- 3x RQS Critical feminized seeds
- 20x Easy-Start seedling pots
- 1x Propagator Pro
- 1x pack of Bacto
- 1x perlite
- 1x fluorescent lights
- 1x instruction manual
- 4x AA batteries
- 1x Royal Queen Seeds catalogue
*You will also need a measuring cup and a stirrer (not included in the kit).
1. Gently remove the foil from the back of the seed packet and place them carefully into a dry container.
2. You will need a shallow container that is large enough to accommodate the seed tray. Fill the container with one litre of lukewarm water (22–25°C/71–77°F). Pour in the packet of Bacto enzyme, allowing it to dissolve before setting the seed tray into the container to soak. The seed tray only needs to be immersed for 5–10 seconds. Do not discard the Bacto mixture after the seed tray has been soaked.
3. After removing the seed tray from your shallow container, poke a 10–15mm deep hole into the soil of each pot, and delicately transfer your seeds from their dry container into each hole. Remember, one seed per pot.
4. Using the supplied propagator, sprinkle a 15mm-thick layer of perlite into the bottom of the tray.
5. Place your seed tray into the propagator, adjust the walls, and position the lid. The lid comes with an on/off switch for the already-attached lights.
6. Check the water level in your reservoir once a day. Your aim is to maintain an even level. After 1–7 days, the seeds should have sprouted, with visible leaves appearing. Once the seedling is 3mm tall, transfer it to your final growing medium.
IF IN DOUBT, THINK SPRINGTIME CONDITIONS
No matter which method you choose, always think about what conditions would naturally be like in spring. In their natural environment, cannabis seeds would start to sprout in-line with the seasonal change from winter to spring. Moisture is still high, and temperatures will be naturally rising. Always ask yourself the question, “Does my germination setup replicate spring conditions”. If the answer is yes, there is a good chance germination will be a success.
Time then to whip out our packages of seeds and get to work. But how do you best set to work, to get these tiny, fragile seeds to grow without problems into small plants?
How to Germinate Cannabis Seeds
Germination relates to the process of a new plant growing from a seed. It is the first step when adding to your cannabis garden. You can purchase the requisite seeds from a variety of sources. On the downside, it means that cannabis seeds vary enormously in quality. We recommend looking at reputable online seed banks to get your supply. However, please note that there are legal issues to contend with if you buy seeds. This is especially the case if you decide to buy them from a source outside the United States.
When buying seeds, opt for mature options with a dark brown appearance and a firm feel. Once you have them in your possession, make plenty of space for them to grow and thrive. Learning how to germinate weed seeds correctly is crucial to enjoying years of healthy plants and fruitful harvests. In this guide, we outline the ideal germination conditions and show you five different methods.
Ultimate Guide to Cannabis Seed Germination
In theory, germinating cannabis seeds is a simple affair. They only need three things: Air, water, and heat. The famed ‘paper towel’ method is incredibly easy as long as you follow the steps outlined below. Here is a quick overview of the best germination practices before we show you the various methods.
Be careful not to over-soak your seeds. Hard seeds should be soaked for a maximum of 32 hours, although 24 hours is usually enough. Soaking too long can damage them. Marijuana seeds begin to sprout when they receive the twin signals of water and heat.
Once the right conditions occur, the taproot starts burrowing through the shell of the seed.
If the root breaks through the shell and there is no water, the seedling will die. Keep the roots moist once the seed sprouts, and make sure there is ample moisture at all times.
This is arguably the trickiest aspect of germination. You have to strike a balance between ‘warm’ and ‘hot.’ Spring temperatures are ideal in a ‘normal’ year. While cannabis seeds can germinate in colder weather, the process takes longer. Seedlings also germinate faster when there is plenty of humidity in the air. If you are concerned about low temperatures, invest in incandescent bulbs, and place them over the seed area.
First and foremost, seeds perform at their best when they are left alone! When you check them for the taproot, handle with care! Try to avoid touching the white taproot because it can easily break off.
You don’t have to plant germinated seeds too deep in the soil, or whatever growing medium you choose. 0.5” – 1” below the surface is plenty. Point the white root downwards into the earth to ensure the seedling is ideally oriented.
Are Your Seeds Good or Bad?
Always opt for dark cannabis seeds as they are the most likely to germinate when kept in the right conditions. White or pale-green seeds have little or no chance of growing.
You may have heard the age-old advice on checking for viable seeds. Apparently, if you can crush seeds between your fingers, they are ‘bad.’ First of all, they won’t be good seeds because you have destroyed them! Secondly, experienced growers know that even flimsy seeds can germinate when exposed to the right conditions.
How to Germinate Marijuana Seeds – 5 Methods
1 – The Paper Towel Method
This is the easiest method and requires cannabis seeds, paper towels, and two clean plates. A word of advice: Choose cheap paper towels because they are non-porous. As a result, you can lay seeds and roots on the surface and not worry about them getting stuck. If you use high-quality paper towels, the roots will grow into them!
It is a simple method, but also a risky one. You could damage the taproot while moving the sprouted seeds, or else the paper could dry out and kill the seeds. In any case, here is the process:
- Use up to four sheets of paper towel and soak them in distilled water. While you must soak the sheet, make sure there is no water dripping off.
- Place two of the paper sheets on one of the plates. Lay the seeds down at least 1” away from one another. Cover with the other two layers of paper towel.
- Cover the seeds with the second plate to lock in moisture. You have created a low-cost dome! Make sure you check the seeds often to see if they have sprouted.
- Keep the seeds in a room where the temperature is between 70- and 90-degrees Fahrenheit.
- Now you must wait! Seeds typically sprout within 1-4 days, although older seeds often take up to a week.
- When checking the seeds, make sure the sheets are saturated. If they are drying out, add more water.
You will know that germination has occurred because the seed will split, and a little root appears. Make sure you don’t touch the taproot when it sprouts or during the transplantation process.
2 – Direct Planting
In nature, a marijuana seed will germinate in the soil and emerge with its taproot growing into the earth. Therefore, you can plant cannabis seeds straight into your growing medium of choice. The main benefit here is that you don’t have to worry about ‘shocking’ the seedling while transporting it.
Your seedling should instantly adjust to the new environment and grow. When using this method, dig a hole 0.5” – 1” deep in soil that is moist but not saturated. Keep things warm with a heating pad or lighting.
3 – Starter Cubes and Seedling Plugs
This has been championed as the easiest germination method. It is effectively a foolproof method. All you have to do is place the seed into the cube/plug and add water. Assuming you put the seeds in a room with the right temperature, germination should occur automatically within a few days. There is a pre-made hole for the seeds, so it is a ‘set it and forget it’ method.
The main downside with this germination method is that such plugs are generally available in packs of 50. Waste is inevitable if you only plan on planting a few cannabis seeds. The plugs dry out in a week or so and become unusable.
You can also use Rockwool cubes as they are cheap and easy to find. However, they are a terrible burden on the environment and bad for your health. Rockwool also has a high pH (which means you must rinse the cubes first) and offers a low cloning and germination success rate.
4 – Overnight Soaking
This is as simple as option #3. It involves nothing more than placing the seeds in a glass of lukewarm water overnight. It is a good idea if you’re using old and hard seeds. The soaking process can breathe new life into them. When you place the seeds in water, they float for a few hours before sinking to the bottom.
The soaking process can breathe new life into old seeds.
If you use a transparent container such as glass, you get to see the white taproot break out! You shouldn’t leave seeds soaking in water for more than 32 hours. Otherwise, seeds that haven’t sprouted yet will drown. If the seeds haven’t germinated by the 32-hour mark, put them in a warm and moist place to complete the process. You should probably use the paper towel method at this point.
5 – A Germination Station
You can purchase a readymade version online. Alternatively, attempt a DIY station by placing a plastic dome over a plate that you then add to a heating pad. Professionally made stations are relatively inexpensive and work rather well. You can buy one for under $40, and their plastic tops ensure better humidity control. With top brands, all you have to do is choose your growing media and plugs to start growing.
Transplanting Germinated Cannabis Seeds
There is no room for a delay once your cannabis seeds have begun to sprout. Now is the time to transfer the seed to its growing medium. Most growers prefer to use small pots, to begin with. Make sure you fill enough pots with loose potting soil and use a pencil to poke a hole around 0.25” deep. Remember, you could break the taproot very easily. Transfer it using tweezers and drop the seed into the hole with the root facing down. Finally, cover it with a thin layer of soil.
For the first few days, use a spray bottle to water the seeds, because adding too much water can drown them. It is worth investing in a pH meter to test the soil regularly and make sure it has enough moisture. If all goes well, the seed should sprout from the earth within a week. If it hasn’t sprouted within ten days, it will probably die.
Turn on your grow light once you have planted the seeds. The heat improves germination rates and speeds up the process of the seedlings opening their first set of leaves. These leaves will remain yellow until exposed to a sufficient level of light in any case. When you plant multiple seeds, you will find that they grow at different rates.
Inevitably, some will fail, while others will flourish. You will have seeds that pop fast and proliferate. Don’t be disappointed if you have a few failures because that’s part and parcel of the growing process. Even when you get everything right, you will inevitably lose a few seeds, and it won’t be your fault!
In this marijuana planting guide, we highlight several of the easiest and most efficient methods for successful marijuana seed germination.