Germination relates to the process of a new plant growing from a seed. It is the first step you must take when adding to your cannabis garden and 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 decide to buy cannabis seeds from a source outside the United States.
When buying seeds, make sure they are matured 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 if you wish to enjoy 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, as they only need three things: air, water, and heat. In fact, the famed ‘paper towel’ method is incredibly easy as long as you follow the steps outlined below. Here is a quick overview of 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. Marijuana seeds begin to sprout when they receive the twin signals of water and heat. Once these conditions are met, 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. You have to ensure the roots are kept moist once the seed sprouts so 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 a couple of 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.
Germinated seeds don’t have to be planted too deep in the soil, or whatever growing medium you choose. 0.5” – 1” below the surface is plenty, and you should 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 as long as they are 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 good 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 the paper towel and soak it in distilled water. While the sheet must be soaked, make sure there is no water dripping off.
- Place two of the paper sheets on one of the plates and lay the seeds down at least 1” away from one another. Cover with the other two sheets.
- Cover the seeds with the second plate to ensure the moisture is locked in. You have created a low-cost dome! Make sure you check the seeds often to see if they have sprouted.
- Please ensure that the seeds are kept 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 out of it. 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 sprout 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 because 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’ type of method.
The main downside with this germination method is that such plugs are generally available in packs of 50. Therefore, if you only plan on planting a few cannabis seeds, you will waste most of the plugs because they dry out in a week or so.
You can also use rockwool cubes as they are cheap and easy to find. However, they are a terrible burden on the environment, bad for your health, have a high pH (which means you must rinse them first), and offer a low cloning and germination success rate.
4 – Overnight Soaking
This is the easiest method as 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 because 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 of the container.
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 sprouted by the 32-hour mark, put them in a warm and moist place to complete the germination process. You should probably use the paper towel method at this point.
5 – A Germination Station
You can purchase a readymade version online or attempt a DIY station by placing a plastic dome over a plate which you then add to a heating pad. Professionally made stations are relatively inexpensive and work rather well; you should be able to 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 absolutely no room for 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, so 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 soil within a week. If it hasn’t sprouted within ten days, it will probably die.
Turn on your grow light once the seeds have been planted. 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 they are 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, but 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!