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.
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
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.
How do you germinate seeds indoors?
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 best germination method depends on the cultivator’s choice. Here are some of the most common ways to pop your cannabis seeds.
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.
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.
We like to use seedling pellets that are made of a mix of compressed peat moss and coco husk. To expand, soak it in water for 10 minutes. Once your seedling pellet has absorbed enough water and has expanded to its maximum size, drain off any excess water. The growing medium should be like a damp sponge that would not leave streaks on the table. Dig a small hole about 1/4 in deep for your seed. Use a spoon to lift the seed out of its bath. If it has popped out a taproot be careful not to damage it. Gently place the seed into the hole and lightly cover it with dirt from the pellet. Now that you have started the germination process, your seedling will come above ground within two weeks. The older the seed, the longer it takes for it to germinate.
Starting from seed is a remarkable journey. Understanding the biology is one thing, but comprehending how a little miracle bean can turn into a gigantic tree that can affect your body and mind is nothing short of an evolutionary miracle. Or rather a co-evolutionary story of plant and human.
Our favorite thing about starting from a seed, rather than a clone, is that you get to see the full life cycle and enjoy a plant that is unique, just like you. An entirely new genetic makeup will enter the world for the first time, and if you’re lucky, something remarkable might be born.
2) Planting your seed
To accelerate germination, you are going to want to soak your seed in a small container with lukewarm water and place it in a dark and warm place for 12-24 hours, but no longer. By drenching the seed, it absorbs the water thoroughly, activating the germination process. Doing this also helps to loosen the shell as it becomes a little softer making it easier for the embryo to crack it open. When your seed sinks to the bottom it is ready to be planted, and sometimes the seed will pop out a small taproot. A seed can still be planted though if it does not sink.
Raising a seedling, however, requires some patience, gentle hands, and a smidgen of luck. Thankfully pot seeds are remarkably vigorous because they are what’s called endosperm seeds, which means they have almost pre-formed cotyledon leaves before you even add water. Below is a brief guide on the techniques we have found yield the most success when starting seeds and raising your seedling to a healthy plant ready for transplanting.
Perhaps the most exciting stage, your baby will typically come above ground in 1-2 weeks. As your seedling comes above the soil, its shell might take a few days to fall off. It’s best to leave it alone, nature has the job covered. If it does not come above ground after about two weeks, the chance of success is dramatically reduced, and it’s best to try again. Even the best seeds have an 85% germination rate. When your seedling comes above ground, it is going to want to see a direct light source.
Seedlings require a medium amount of light in which it has enough to grow but not too much light that it gets burned. Leaving your seedling in direct sunlight will cause the leaves to curl, while too little light will cause the seedling to stretch. If growing outside, seedlings want to see a direct light source to stop them stretching. If inside, a sunny windowsill with more than half a day of sunlight works wonders. Otherwise, 18 in away from a growing light works excellently. Your seedling should not stretch more than 6 in at most. We’ll cover lighting in more depth in a later blog.
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.
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.
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
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.
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.
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.