Germinating weed seed has leaves

How to germinate cannabis seeds

So, you’ve decided to grow your own cannabis plants. You purchased a pack of seeds, assembled cultivation materials, cleared a space in your garden, and are ready to grow your first cannabis crop . With everything in hand, it’s time to begin the very first step of cannabis cultivation : germinating seeds.

What is germination?

Germination is the first stage of the cannabis growth cycle : the process that brings a cannabis seed out of its hibernation period and starts the cannabis growth process. After all, seeds in a bag don’t spontaneously start developing roots. Also known as “popping” seeds, seed germination begins when a seed receives environmental cues letting it know the setting is perfect to start growth.

Germination is the process that brings a cannabis seed out of its hibernation period and starts the cannabis growth process. Photo by: Gina Coleman/Weedmaps

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When a seed enters an environment with enough moisture, it will increase in size and slowly break out of its shell. A seedling or germ forms from which roots will emerge, helping the baby plant absorb nutrients from the soil. Seeds naturally develop roots facing down and stems stretching upward, allowing the young cannabis plant to simultaneously feed off light and earth.

It’s essential to acquire high-quality cannabis seeds for germination, as these will go on to become high-quality cannabis plants. Seeds that are fresh-feeling or too green indicate that they haven’t reached full maturity, while pale-green, white, or very dark cannabis seeds may have trouble sprouting. However, it’s tricky to know the outcome of a popped seed, so trying may be worthwhile. If you’re not ready to pop your seeds yet, store them in a dark, cool place until it’s time for germination.

Preparing to germinate cannabis seeds

Germination itself is a crucial aspect of cannabis cultivation. The seed germination process is the foundation of every marijuana plant, and steps can be taken to boost successful popping. For example, some cultivators improve germination attempts by soaking seeds in 1% hydrogen peroxide or a compost tea for 12 hours beforehand to kill any dangerous pests.

The environment in which seeds germinate also plays a role in the outcome. While there are several different germination methods, each requires proper moisture, minimal handling, and warm springtime temperatures between 68-72 degrees Fahrenheit.

How to germinate cannabis seeds

The best germination method depends on the cultivator’s choice. Here are some of the most common ways to pop your cannabis seeds.

How to germinate seeds in soil

Soil is an easy, more natural method with which to germinate your cannabis seeds. The soil protects the fragile roots from any interference, and soil is, after all, where a cannabis plant would grow in the wild.

Soil is an easy, more natural method with which to germinate your cannabis seeds because the soil protects the fragile roots from any interference. Photo by: Gina Coleman/Weedmaps

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First, make sure you use the correct type of soil, either gently fertilized potting soil or a seed starter with a pH level of approximately six (6). The soil contains the right acidity and enough nutrients to strengthen your young cannabis plants for the first two weeks. Be careful not to add more nutrients, or you risk overfeeding and killing your seeds.

Place the soil in a small pot and use your finger or a pencil to push a small hole in the dirt, a bit more than half an inch deep. Insert the seed into the hole and bury it with soil. From this point on, don’t touch your seed. The young plant is fragile and knows how to position itself in the soil bed.

Gently water the soil with a spray bottle and situate your pots under a fluorescent lamp. Keep seeds away from the windowsill, as the temperature is too volatile for germination. In general, you’ll want to keep the temperature in the range of 70 to 80 degrees Fahrenheit.

Monitor your soil every day and keep it moist. Within four to seven days, you should see tiny stems sprouting from the soil.

When the seedling stems reach two to four inches in height, it’s time to transplant your cannabis into larger pots with more room for roots to spread down and out. After you’ve done this, you’ve successfully germinated your cannabis seeds into proper, young plants.

How to germinate seeds in water

You can also germinate your seeds by placing them in water. It’s slightly faster than the soil method, but you need to adjust your environmental factors accordingly. Remember, successfully germinating seeds requires a perfect balance of ideal growing conditions. When germinating in water, seeds need only 24-48 hours to pop their stems, though cultivators can keep them soaking for up to a week as needed. Water germination is faster because the seed gets all the moisture it needs immediately, and the shell softens and cracks more easily after soaking.

To employ water germination, fill a glass with tap water and let it sit until it reaches room temperature or around 65 degrees Fahrenheit. Add two to three plant seeds per cup and allow them to sit, watching for any changes. Change the water to fresh tap water every two days, making sure it stays at room temperature.

The seeds should start sprouting in about two days, though older seeds can take up to a week to sprout. You can remove them from the water and place them in the soil at any point once they’ve sprouted. Once the roots are about five millimeters long, they need to be planted.

The downside of water germination is that once they’ve popped, you’ll need to maneuver them into their growing medium manually. This is a delicate process, as germinating seeds are extra fragile, and any harm risks the development of your plants. Make sure to place the seed roots down in the soil when you transfer to a pot.

How to germinate seeds using paper towels

The paper towel method is also a common way cultivators pop their seeds. Some even use this method with cotton pads instead of paper towels, but the necessary steps are the same.

To germinate seeds this way, lay one paper towel on top of a countertop, place a few seeds, and cover them with a second paper towel.

Lay one paper towel on top of a countertop, place a few seeds, and cover them with a second paper towel. Photo by: Gina Coleman/Weedmaps

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Use a spray bottle to moisten the paper towels and then store the cushioned seeds between two plates, under a face-down bowl, or gently place them in a plastic bag. Maintain a temperature of about 72 degrees Fahrenheit, keeping the paper towel wrapped seeds in the dark and away from a windowsill. In two to five days, the seeds will pop inside the paper towel sandwich and emit tiny roots, ready to plant when they reach about five millimeters in length.

Use a spray bottle to moisten the paper towels and then store the cushioned seeds between two plates, under a face-down bowl, or gently place them in a plastic bag. Photo by: Gina Coleman/Weedmaps

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The paper towel method also has its risk, as the fragile seedlings can be damaged during the potting process. The tiny roots can also get tangled in the paper towels, so make sure to move the seeds to potting soil before roots grow too long. Use your hands or tweezers to gently remove each seed from the paper towels and place them in a prepared growing medium.

How do you germinate seeds indoors?

Whether you’re planning an indoor cultivation or outdoor grow, it’s best to germinate your seeds indoors. It’s easier to maintain proper temperature, light exposure, and moisture inside, and you can protect your seeds from the elements. Indoor germination, whether using soil or paper towels, will ensure your cannabis seeds have the best chance for survival.

To germinate seeds indoors, use any of the methods described above. Within a few days, you’ll have popped seeds ready to transfer to a growing medium.

Do you need to germinate seeds before planting?

While many plants can be germinated in the ground, cannabis seeds are fragile enough that you should germinate them before planting.

Once your seeds have sprouted roots, they should be planted in soil, a soil-less medium, or in your hydroponic setup. Make sure not touch the root, caring for and navigating the seedling so that the roots face downward. Plant the seed about one inch deep in your growing medium, cover lightly, and allow for about a week for the seed to emerge from the soil. If the seed hasn’t poked through by day ten, it likely didn’t survive.

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Hopefully all of you aspiring growers have been able to get your seeds so we can move to the next step: germination.

Take great care handling seed and seedling. Most flower and vegetable seeds are simply planted directly in the soil, but because of the value of cannabis seeds, germinating seeds prior to planting is encouraged. Growers can achieve a much higher survival rate by germinating in a non-soil medium and then transferring the seed to soil once the tap root has emerged from the seed.

Here is one of the simplest and most successful methods: Put a double layer of paper towels on a dinner plate, then thoroughly soak the towels with water and tilt the plate to drain off the excess. Place your seeds on top of the wet towels and cover with another double layer of soaked paper towels. Be sure excess water is drained off—you don’t want the seeds to be swimming.

Cover the plate with an upside-down plate or pot lid. A plastic bag or plastic wrap also works. Don’t make the seal tight—you want to leave some openings to allow air flow.

Keep the germinating seeds away from direct light. For best results, keep them at about 75 degrees Fahrenheit. A radiant heat source, like a heating pad, helps expedite the process. If you’re using a heating pad, be sure to keep the heat setting on low and place a folded hand towel between the heating pad and plate: Direct contact between the plate and heat source can cook your seeds.

Under the right conditions, seeds usually open in one to five days, so check them daily. Do not allow the towels to dry, and add water as needed to maintain moisture. Some seeds can take as long as 10 days to germinate, but if seeds have not opened within 10 days, they are not viable.

When the seeds open, the first thing to emerge is the root. Once the root sprouts it can grow quite fast.

When the root grows to a few millimeters in length, the seed is ready to be transferred to soil. Always take great care not to damage the tap root when handling. The best soil to use for a sprouting baby ganja plant is a “seed starter” or “seedling” mix. These are light neutral blends with very little fertilizer. Heavily fertilized soils will kill seedlings quickly, and cannabis seedlings prefer loose, aerated soil that their roots can easily penetrate. A bag of good starter soil is easily identifiable: When you pick it up, it should feel light and fluffy. Soils that are heavy and compact are not good for seedlings.

Now, on to potting (no pun intended). A healthy seedling will be ready for transplanting into larger container, with richer soil, in about a month. A 16- to 20-ounce container is ideal for a seedling’s first home (many growers use a Solo cup). The container must drain, so punch some holes if needed.

Fill your container with pre-moistened soil and create a hole about a half-inch deep for your seed. The tip of a pencil works well for making the right sized hole. The seed should be about a quarter-inch below the surface.

Place your germinated seed, root down, into the hole and cover lightly. Do not pack the soil on top of the seed; a light protective layer of soil is all that is needed.

Once they sprout in one to three days, new seedlings will need lots of light, and fluorescent grow light works best. Give your baby ganja plants 16 hours of light per day.

It’s very important to have a breeze on your plants immediately. A fan placed at the proper distance and speed should create a breeze just strong enough so your plant “dances,” but not so strong that it’s bent in one direction.

Without a breeze, indoor ganja plants won’t receive the stimulus needed to develop sturdy stems and branches, which the plant will need to bear the weight of big, sugary buds.

The Potanist is written by Bud Baker and Herb Green (yes, those are pseudonyms; yes, they are real people). Reach them at [email protected]

Graphics by Stephanie Rudig

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