Learn how to germinate marijuana seeds on your FIRST try! Reach 100% seed germination rates by using our step-by-step tutorial. Just when we thought we'd seen all the weird gardening hacks … Cannabis sativa sp. is commonly known as marijuana and has been grown throughout the world for thousands of years. Cannabis seeds germinate in 3 to 7 days, though some varieties may take 10 to 15 days. While germination is a natural…
How to Germinate Cannabis Seeds
An in-depth guide on how to germinate cannabis seeds. Discover different techniques on how to germinate marijuana seeds to ensure a successful cannabis crop.
Everything has a beginning.
Cannabis seeds, like all seeds, must undergo the germination process before it can grow into a weed-yielding beauty.
Countless cannabis germination guides litter the internet. However, none go as in-depth as our seed germination tutorial. Read along to learn how to germinate marijuana seeds like a pro.
You’ll discover everything you need to know about the art of germinating marijuana seeds. From the necessary equipment to different germination methods and everything in between, we’ve got you covered.
The Chemistry Behind Cannabis Seed Germination
Cannabis seeds require the right conditions to sprout.
Without the proper temperature, moisture level, or oxygen saturation, weed seeds will not germinate. Although you can readily germinate seeds outdoors, nothing beats controlled germination indoors.
Let’s take a look at the three primary elements that influence the germination rates of marijuana seeds.
Water is the key player in the process of germinating marijuana seeds.
The outer-layer of the cannabis seed acts as a protective casing that provides a two-fold defense — prevent damage to the inner embryo and prevent minimal moisture from premature germination.
However, if the marijuana seed is saturated with water, it will eventually absorb the moisture and kick-off the germination process.
Once the embryo activates through water saturation, it requires oxygen to jump-start the respiration process. Oxygen fuels respiration, which unlocks food stored within the embryo.
After the respiration process, the embryo consumes the food stores, which in turn produces energy. Energy is the necessary product that propels the germination stage onwards.
Even if cannabis seeds have access to water, oxygen, and energy, it’s all for nothing unless it has access to warmth.
As long as cannabis seeds experience 72-78°F during the initial germination process — they’ll burst forth from the ground and spread their primordial leaves under the sun or artificial light.
The three most important elements for successful weed seed germination
Why It’s Important to Germinate Weed Seeds Indoors
At its core, the germination process lays the foundation of cannabis plants.
Overall, marijuana plants will underperform without proper germination techniques compared to those that experienced ideal conditions during the germination process. Therefore, it’s always best to harness an indoor environment when germinating marijuana seeds.
What to Look For Before Germinating Marijuana Seeds
Before you begin the germination process, there are a few things you must look for.
Let’s take a brief look at each.
Damaged Marijuana Seeds
Ordering feminized or autoflowering cannabis seeds online is the best way to acquire top-shelf genetics.
The seeds, however, may experience a few bumps on the road during the shipping process. With this in mind, you must look over each seed to ensure there isn’t any damage.
As long as each weed seed is undamaged, the germination process will be smooth.
The Cannabis Seed’s Age
Next, it’s a good idea to write down the date on each seed pack once received.
By doing so, you’ll have a clear understanding of a seeds’ age. Like all things, cannabis seeds lose their luster as the years go by. Cannabis seeds may remain viable for decades. However, germination rates decrease over time.
Therefore, you should only germinate seeds that are properly stored for a maximum of 6-months.
The Cannabis Seeds Color
Lastly, you must check the cannabis seed’s color.
Cannabis seeds come in different sizes and exhibit various markings across the outer seed coat. However, the seed’s color is an excellent indicator that represents seed maturity.
In other words, light green to pale white seeds are immature and are likely unviable. Therefore, always make sure that your cannabis seeds are light to dark brown color before germination.
Take a close look at the seeds that you receive for damage or discoloration
Should You Use a Seedling Heat Mat?
Many new cannabis cultivators ask if they should incorporate a seedling heat mat into the equation.
Although seedling heat mats are excellent tools to ensure fast germination, they are not always necessary. Seedling heat mats work by producing a gentle warmth that won’t rapidly dry cannabis seeds during the germination process.
However, they may be overkill if you utilize them during hot days, such as those during the summer months. Alternatively, they are essential during colder months during the winter. Therefore, you can choose to harness a seedling heat mat based on the time of year that you choose to germinate marijuana seeds.
Three Easy Methods To Germinate Cannabis Seeds Indoors
Now that you have a broad understanding of germinating marijuana seeds let’s get some weed seeds poppin‘ with a few different step-by-step tutorials.
You’ll have a better idea of which germination technique to choose once you’re done reading this section.
1. How to Germinate Marijuana Seeds in Soil in Five Easy Steps
If you want to germinate weed seeds au natural — there’s no better option than using soil.
Here’s a list of what you’ll need to germinate cannabis seeds in soil:
- Feminized or autoflowering cannabis seeds
- Eco-friendly “starting” container
- Heat mat (optional)
As you can see, the list above isn’t extensive in the least. In other words, germinating marijuana seeds in soil is incredibly affordable.
First, fill an eco-friendly starting container with soil.
The golden rule? Don’t pack down the soil. Remember, the soil you choose must exhibit a loamy consistency. Hardpack soil does not allow proper water drainage and oxygen circulation, which, as you learned previously, are critical components for the seed germination process.
Furthermore, if you choose to use a heat mat, place the eco-friendly containers on top to warm the medium adequately.
Label each container.
The last thing you want to do is forget what seed you placed into each container — especially if you’re germinating multiple cannabis strains at once.
Now, it’s time to sow the cannabis seed.
Create a small hole that’s roughly 0.25-inches (6mm) deep. Gently place the seed inside the hole and cover it. It does not matter which direction you put the seed — believe us when we say that the seed and gravity will sort things out.
It’s important to note that each eco pot should contain a single cannabis seed.
Gently pour a small amount of water into the area where you buried the cannabis seed.
At this point, you must ensure that the cannabis seed never dries out. Once the germination process begins — there’s no turning back. Therefore, allowing cannabis seeds to dry will guarantee inadequate germination or premature death.
Ultimately, you must monitor the soil and continuously apply water until the seed sprouts.
The final step is patience.
The moment the seed is planted, most beginners ask: how long does it take to germinate cannabis seeds, or how can I germinate my seeds fast?
Healthy cannabis seeds typically break the surface within 2-4-days. Older seeds, however, may take upwards of 12-days to sprout.
The germination phase is an incredibly vulnerable moment for cannabis seeds. Therefore, Do not — we repeat — do not dig up the seed to “check on it.”
This is what you can expect after you successfully germinate your cannabis seeds in soil
2. How to Germinate Marijuana Seeds Using Paper Towels In Five Easy Steps
One of the most popular germination techniques is the paper towel method.
Here’s a list of what you’ll need for this low-budget method:
- Feminized or autoflowering seeds
- Dinner plate
- Paper towels
- Spray bottle
- Heat mat (optional)
Now that you’ve gathered the necessary supplies let’s get crackin‘.
Place two to three sheets of paper towels on top of a clean dinner plate. If you decide to use a heat mat to increase the temperature, place it under the dinner plate.
Label the dinner plate with the name of the cannabis strain of choice.
Place up to 10-seeds per plate.
You must make sure that a minimum of 1-inch adequately separates the seeds.
Spray water on the seeds until the paper towels are completely saturated. Once done, place a new layer of 2-3 paper towel sheets on top of the seeds. Use the spray bottle to soak the new paper towel addition.
Remember: the paper towels must always remain saturated with water. If allowed to dry, the cannabis seeds will fail to germinate.
The germination process should occur within 24-48-hours. After 48-hours, gently peel back the upper paper towel section. If the seeds germinate, you will see cracked-open seeds with an emerging radicle.
At this point, it’s time to move the germinated seed to its new home with a pair of tweezers. This final step requires extreme care because the radicle is fragile, and if broken, the embryo within will die.
Be careful when you use the paper towel method and make sure to label each plate
3. How to Germinate Marijuana Seeds Using Rooting Cubes in Five Easy Steps
Germinating weed seeds with rooting cubes is the ideal method for beginners and professionals alike.
Overall, rooting cubes provide the ease of the paper towel method and the soil technique’s efficiency. Let’s take a look at everything you need to when germinating marijuana seeds with rooting cubes.
- Feminized or autoflowering seeds
- Rooting cubes
- pH 6.0 water
- Rooting tray
- pH meter and pH up or down
- Heat mat (optional)
First and foremost, place the rooting cubes in the rooting tray. If you decide to use a heat mat, place the tray on top.
Next, label each rooting cube or tray with the appropriate name of each cannabis strain.
Use a pH meter and pH solution to achieve a pH of 6.0.
The amount of water you pH depends on the number of rooting cubes. Start with one cup of water if you are germinating less than ten seeds.
Germination cubes require a pH of 6.0 because they are typically made from peat moss, rockwool, or other soilless-based mediums. Therefore, a pH of 6.0 will ensure the best possible results once the seed germinates.
Each rooting cube is equipped with a pre-made hole.
Place one cannabis seed per hole. You may tear off a small piece of the substrate to cover the opening. Once done, saturate the rooting cube with pH 6.0 water.
You must make sure that the rooting cube never dries out. Remember, cannabis seeds must remain moist until they sprout to the surface.
Once again, patience is the final step when you learn how to germinate cannabis seeds with rooting cubes. Overall, cannabis seeds may emerge from the rooting cube within 2-4-days. However, germination may take as long as 7-days.
There are a lot of rooting cubes to choose from, but the germination process remains the same
How to Germinate Old Cannabis Seeds
Now that you understand how to germinate healthy cannabis seeds let’s quickly discover how to germinate old marijuana seeds.
As you become infatuated with the world of cannabis, you’ll soon begin to stack an extensive seed collection. Don’t worry; we’re all seed hoarders at heart because there are so many incredible cannabis genetics out there.
Eventually, however, you’ll notice that you have more than a few old cannabis seeds. Luckily for you — all is not lost.
Here’s our tried and true technique to give your old seeds a boost during the germination process.
Cannabis Seed Scarification
Scarring cannabis seeds is incredibly simple.
All you need is a nail file or a piece of sandpaper. Use the file or sandpaper across the surface of the seed in question. You do not need to use an immense amount of force, but instead, a few good scrapes to scar the seed’s outer shell will do.
The point of seed scarification is to allow water to penetrate the seed coating easily. By doing so, the embryo receives a jump start that initiates the germination process.
Once the seeds are scarred, you may choose one of the three above mentioned techniques to complete the germination process.
A few readily available tools to get your cannabis seed scarification done
The Best Way To Germinate Marijuana Seeds
Now that you’re done reading this guide on seed germination — which method will you choose?
The soil, paper towel, and rooting cube methods are all tried-and-true and provide excellent germination rates. Remember, cannabis seeds are an investment, and you must use the best germination method possible to ensure a healthy cannabis crop.
You have one chance to germinate each seed the right way, and by using this guide, you’ll make each seed count.
The weird method Redditors are using to germinate seeds
At one point or another, every gardener has found themselves late on starting their seeds. Whether you’re a beginner at gardening or just having a year when everything has been a bit overwhelming, not planting the seeds of your favorite vegetable on time can be frustrating. That’s where Reddit comes in. Reddit gardening has taken off recently, in large part due to the discovery that you can germinate seeds in the Instant Pot (you know, that thing in your kitchen you use to make stews and rice).
The Instant Pot method
The Instant Pot method involves placing your seeds in the Instant Pot on the yogurt setting. It can be credited in large part to a scientist in Ottawa who, during the 2020 growing season, found herself unable to find seeds until it was well past time to germinate them. Now, could a regular gardener have figured this method out? Perhaps. But for scientist Lyanne Betit, this was a no-brainer.
Thanks to her knowledge of organic chemistry, biochemistry, and gardening, Betit came up with the idea to jumpstart her seeds’ germination in the Instant Pot. She was already behind on the growing season and needed a way to speed things up. Knowing that seedlings in warmer climates can thrive in 89° to 91° F. (32 to 33 degrees Celsius), Betit knew the yogurt setting on the Instant Pot was the perfect consistent environment to encourage seed sprouting.
The Instant Pot method works best for warm weather crops like tomatoes, peppers, and cucumbers. It can be especially helpful if you’re behind on the season like Betit, or if you just want to speed up the initial germination process. For those who don’t have a lot of surface area to dedicate to germination, the Instant Pot method is perfect.
How it works
Thanks to the Reddit gardening community, we have a good idea of how this method works. You start by placing the seeds between layers of damp paper towels and putting them in a Ziploc bag. The Instant Pot is turned on and set to the yogurt setting, then the Ziploc(s) with the damp paper towels and seeds is placed inside. There are some seeds that need a slightly cooler temperature and won’t do well inside. Betit discovered you can place these seeds in a Ziploc bag on the lid of the Instant Pot instead. It’s a cooler temperature than inside but is still consistent enough for seeds to germinate.
Why is this possible?
Gardeners often germinate seeds indoors so the seedlings are a good size for transplanting when the outdoor growing season begins. Because seeds require a steady temperature within a set range to germinate and thrive, the Instant Pot provides that environment. It’s warm, void of any drafts, and is a controlled environment — similar to a greenhouse, if you will, but on a smaller scale.
Depending on the seed, the consistent environment is able to help seeds germinate from one to seven days. This method, however, isn’t recommended for cool-weather crops like the Brassica family (cabbage, cauliflower, broccoli, etc.) because the environment will be too warm for them to thrive and survive.
You can try it at home, too!
If you have an Instant Pot, try this method at home! If you’re unsure of the temperature your seeds need to germinate and the packet doesn’t say, the University of California Agriculture and Natural Resources has compiled a list of of ideal seed temperatures. To successfully execute Reddit gardening’s Instant Pot method, you’ll need:
- Your desired seeds
- Paper towels (dampened)
- Ziploc bag(s)
- Sharpie (to mark what seeds are in which bag if germinating more than one type)
- A strainer
- Potting containers for germinated seeds
- An Instant Pot (but of course!)
A step-by-step guide
Starting the Instant Pot method may feel a bit weird at first, and you might not get it right the first try. Here’s a step-by-step guide you can follow to help execute it as best you can:
- Make small piles of four to five seeds and dampen one paper towel per pile (so, if you have three piles of seeds, you’ll need three damp paper towels).
- Place the seeds one inch apart on the bottom half of each paper towel, leaving room for roots to sprout.
- Fold the paper towel in half and place it inside the Ziploc bag. You’ll want one bag per set of seeds, making sure to label each bag with the plant type.
- Pour half a cup of water into the Instant Pot. The water will keep the Instant Pot from burning the bags, as well as help create a warm, humid environment for the seeds. Place the strainer inside.
- Set the Instant Pot to the lowest temperature possible on the yogurt setting. This should be 91° F. Set the Instant Pot for the max time available for your version, which will be anywhere from eight to 99 hours.
- Place the Ziploc bags into the strainer (stacking is OK!) and put the lid on the Instant Pot.
- Be sure to check on your seeds two times a day after the first day, as some may germinate faster than others (especially if they’ve been bought recently or have a softer coating). A majority of the seeds will germinate within a week, and you’ll know they’re ready to be transplanted to potting containers when the tiny white root sprouting from the seed is one to two inches long.
- Be mindful of mold. When you check on the seeds, examine the paper towels to make sure there’s nothing fuzzy growing. Because it can be taken care of in its early stages with a mix of water and hydrogen peroxide, you don’t want to let the mold get out of hand and ruin your germination.
- The seeds should be removed once they’ve germinated using a sanitized pair of tweezers. Grab the body of the seed (taking care not to touch the root) and transfer them to a pot with soil. Make a small hole in the top of the soil, place the seed in with the root pointing down, and bury only the white root, leaving the body of the seed above the soil. Give it a tablespoon of water.
Once germinated and planted, seedlings will need around 12 to 16 hours of light a day. If you don’t have access to this amount of light naturally, be sure you have some grow lights on hand! Thanks to Reddit gardening, seeds all around the world may germinate just a little bit faster from here on out.
How to Germinate Cannabis Seeds
This article was co-authored by Lauren Kurtz. Lauren Kurtz is a Naturalist and Horticultural Specialist. Lauren has worked for Aurora, Colorado managing the Water-Wise Garden at Aurora Municipal Center for the Water Conservation Department. She earned a BA in Environmental and Sustainability Studies from Western Michigan University in 2014.
There are 10 references cited in this article, which can be found at the bottom of the page.
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Cannabis sativa sp. is commonly known as marijuana and has been grown throughout the world for thousands of years. Cannabis seeds germinate in 3 to 7 days, though some varieties may take 10 to 15 days. While germination is a natural process, factors such as light, humidity/moisture, and temperature must be controlled for cannabis seeds to sprout.