How Long to Germinate Weed Seeds?
In order to produce marijuana buds, the cannabis plant needs to go through 4 growth stages like the germination stage, the seedling stage, the vegetative stage, and the flowering stage. For the purpose of simplifying the process of cannabis cultivation to our readers thinking about becoming marijuana growers, in this article we’re focusing on the germination stage and how long it takes to germinate weed seeds.
Germination, or sprouting, is the first stage of cannabis cultivation during which the cannabis seeds are placed in water in order to develop sprouts. Some marijuana seeds may germinate while others won’t, and the sprouting success rate mostly depends on the quality of the seeds.
In order to increase the germination rate of cannabis seeds and increase the chances of successful germination, check out our guide below.
The 411 on Germinating Marijuana Seeds
Before you start cannabis cultivation and germinating seeds, you will definitely benefit from reading the following tips:
- Purchase high-quality seeds from a verified seed bank.
- Purchase growing lights required for the following stages like LED, CFL, or HID grow lights.
- Use a heating pad underneath the seeds to help aid germination and maintain proper temperatures.
- Pre-soak seeds in 1% hydrogen peroxide or compost tea for 12 hours in order to improve germination or kill pests.
- Keep the marijuana seeds under a temperature of about 72 degrees Fahrenheit (22 °C).
- Keep the seeds away from your windows and direct sunlight.
- Purchase jiffy pellets or starter plugs for germinating weed seeds.
How Long Do You Need to Germinate Cannabis Seeds
The time needed for seeds to sprout is not always the same, but if you’ve provided your cannabis seeds with the right conditions, germination should usually start between 12 to 36 hours after you’ve soaked the seeds. Warmth, moisture, and darkness will accelerate cannabis seed germination, and the whole process can be over within 5 to 10 days (during which the seeds will be completely out of their shell). The more ideal your germination environment is, the faster your cannabis seeds will start to germinate.
Choosing a Germination Method
There are a few ways that you can germinate your seeds and the most common ones include:
- The paper towel method;
- The glass of water method;
- Planting directly into the soil.
The Paper Towel Method
This germination method is one of the easiest ways to germinate seeds and it only requires paper towels soaked in tap water. The two pieces of paper towels are soaked in water, and the cannabis seeds are placed between the sheets. Additional water should be added so that the seeds are moist, and excess water should be drained away. Furthermore, the temperature in the area where they’re kept should be between 70-90°F (21-32°C).
Once the seed splits and a sprout appears, you’ll know that the seed has started germinating. The sprout is called the taproot, and it’s a sign of successful germination. After the seed starts to split, make sure you’re very careful with the taproot when planting it, and don’t touch the seed as it begins to split.
The Glass of Water Method
This is the most common germination method for beginner growers since all it takes is placing the seeds in a glass of water. The seeds should be placed in a half-filled glass of water at a temperature of about 71°F (22°C), and the seeds will start sprouting between 3-5 days and develop taproots. After the roots reach 2–3 mm they should be transferred to soil pots, and over time the germinated seeds will develop into cannabis plants.
Keep in mind that not all seeds will germinate. Some seeds will sink to the bottom and some will float. The ones that float are probably not viable, and they need to be thrown away. Use tweezers when transplanting the taproot into a growing medium, and start preparing the proper lighting system for your marijuana plant.
Planting Directly Into the Soil
This germinating technique isn’t recommended for beginner cannabis growers since they need to be informed about the proper nutrients, appropriate pH soil, and humidity levels that the growing medium should have.
What you’ll need in order to plant directly into the growing medium are pots filled with premium-quality soil that’s been soaked in water. This method of germinating cannabis seeds prevents moving the seeds when they’re at their most fragile state, and that’s exactly the reason why most experienced growers prefer it.
What to Avoid When Germinating Cannabis Seeds
If you are planning to grow your cannabis plants from seeds and germinate them, you’ll need to avoid some common mistakes that cannabis growers make.
Letting the Germination Medium Dry Out
While germinating, always make sure that the paper towels stay moist. This is especially important if you have a heat source placed above the germinating seeds. It’s better to opt for rock wool cubes germination as opposed to hydro since it helps retain moisture.
Overwatering your cannabis seed may result in bud rot and ruin the potential for the cannabis seed to grow into a cannabis plant. Make sure you provide your plants with enough water, but not excess water.
Avoid Leaving Seeds to Germinate Longer Than They Should
If you end up germinating using the paper towel method, make sure you leave the seeds to germinate, and transplant them before the cotyledons appear. The best time to transplant is once the taproot is between 1-2 cm in length.
Do Not Germinate Directly in Soil
If you’re a less experienced grower, don’t start by germinating in soil. You could always try germinating using the paper towel method, jiffy pellets, or peat plugs, which will make it easier to maintain proper temperature and humidity.
Maintain the Appropriate Temperature and Humidity for Germination
The right environment is essential for successful germination. Ideally, the germination medium should have a temperature of about 72 degrees Fahrenheit (22 °C) and 70% relative humidity. Lower values may make the germination less successful, while higher values might result in rot or fungus.
Plant the Seeds Correctly
The seed needs to be planted with the root facing down, so when it opens at the tip it lets out the root. The seed shouldn’t be buried too deep because the seedling may never emerge, or, on the other hand, if it’s too close to the surface, the stem can grow weak. Make sure that the top of the seed is just below the surface of the growing medium, and the root faces down.
Final Thoughts and Transplanting Germinated Cannabis Seeds
After the taproot appears, you can transfer your germinated seed into a growing medium and wait for the three stages that follow in the marijuana growth cycle. You can choose to grow in coco coir, hydroponic, or soil, depending on your preferred planting medium. Young plants are pretty vulnerable, which is why you should be extra careful when transferring them in the potting soil. As you grow more cannabis plants, you’ll learn more about the germination process, which will make you more confident each time you germinate new seeds.
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Jorge’s Cannabis Encyclopedia: Seed Germination
Cannabis seeds need only water, heat, and air to break dormancy and germinate; they do not need extra hormones, fertilizers, or additives. Seeds sprout without light in a range of temperatures. Strong, viable, properly nurtured seeds germinate in 2 to 7 days. At germination, the outside protective shell of the seed splits, and a tiny, white sprout (radicle) pops out. This sprout is the root, or taproot. Cotyledon, or seed, leaves emerge on a stem from within the shell as they push upward in search of light.
Break dormancy: Put newly harvested seeds in the refrigerator for a week or two to simulate winter. Remove and germinate. Seeds will germinate more uniformly because they all come out of dormancy at the same time.
Timeline for Germinating Most Seeds:
At 36 to 96 hours – Water is absorbed, root tip (radicle) pops through outer shell and is visible.
At 10 to 14 days – First roots and root hairs become visible.
At 21 to 30 days – At least half of seeds are rooted by day 21. Seeds not rooted by day 30 will probably grow slowly.
Once seeds are rooted, cell growth accelerates; stem, foliage, and roots develop quickly. Seedlings develop into full vegetative growth within 4 to 6 weeks of germination.
Seeds are Prompted to Germinate By:
Water: Soaking seeds in water allows moisture to penetrate the protective seed shell within minutes. Once inside, moisture continues to wick in to activate the dominant hormones. In a few days, hormones activate and send enough signals to pro- duce an initial root tip. The white radicle (rootlet) emerges to bring a new plant into the world. Once a seed is moist, it must receive a constant flow of moisture to transport nutrients, hormones, and water so that it can carry on life processes. Some seeds need lots of moisture to wash out the dormancy hormones in the seed coat, and if they do not get enough moisture, they do not germinate. Conversely, too much water deprives the seed of oxygen, reducing its quality or destroying it. If fragile germinated seeds are allowed to suffer moisture stress now, seedling growth will be stunted. Soaking most seeds in water for 12 to 24 hours is all they need to initiate germination. All the nourishment for a seed’s initial growth requirement is pulled from the fleshy cotyledons, or seed leaves. Water seedlings with low-EC (electrical conductivity) household tap water during the first week or two of life. Supple- mental nutrients are unnecessary and if applied in excess can disrupt internal seed chemistry. Some gardeners prefer to germinate seeds using distilled or purified water that contains virtually no dissolved solids.
Temperature: Overall, cannabis seeds germinate in temperatures from 70°F–90°F (21°C–32°C) and grow best at 78°F (26°C). Temperatures below 70°F (21°C) and above 90°F (32°C) impair germination. Low temperatures delay germination. High temperatures upset seed chemistry causing poor germination. Seeds germinate best under the native conditions and temperature ranges where they were grown.
Air & Oxygen: Sow seeds twice as deep as the width of the seed. For example, 0.125-inch (3 mm) seeds should be planted 0.25 inches (6 mm) deep. Adequate oxygen is un- available for seeds planted too deeply, and tender seedlings have insufficient stored energy to drive through deep layers of soil or crusty hard soil when sprouting.
Agricultural Astrology — Planting by the Moon
Ancient Babylonians and Egyptians planted and harvested based on moon phases in relation to geographic location. The premise is that plants grow better when planted during the appropriate moon phase.
Moon phases cause ocean tides to rise and fall. They also affect the rise and fall of moisture in soil and fluids inside plants. The moon phase influence is said to be the same indoors, outdoors, and in greenhouse-grown cannabis.
Cannabis gardeners who plant by the moon report faster-sprouting seeds that grow into vigorous plants. However, scientific evidence is lacking in regard to cannabis and other plants’ relationship with agricultural astrology.
Seeds need oxygen from the air to germinate. Growing mediums that are too moist (soggy) will cut off oxygen supplies and the seeds will literally drown. Cannabis seeds germinate best when moisture is between 60 and 70 percent.