How To Germinate Cannabis Seeds In Soil

Luke Sumpter

Cannabis Journalist & Health Science Researcher

Luke Sumpter

Last updated: March 28th, 2024

If you come to grow cannabis, you might be perturbed by how many ways there are to do it. What's more, even getting started can be complex, with several options for germination. Overwhelmed, you might be wondering whether you can germinate directly in the soil and save yourself some time and energy. The good news is that you can, and it's easy. Here, we'll show you how to do it.

Why Germinate Cannabis Seeds In Soil?

Can you germinate cannabis seeds directly in soil? You sure can. In fact, it's a straightforward and effective method, and depending on what you're growing and how you want to grow, it's often the preferred option. After all, seeds germinate directly in the soil in nature, so why not replicate this process in the grow room?

Some choose starter packs or propagation chambers, where the seeds germinate in very small soil blocks, in enclosed and humid spaces. Others choose to germinate in soil directly in the ground or the plant's final pot.

There are two main reasons you would germinate directly in the final pot—the first is ease. Whilst germination rates and overall plant growth are often better if you germinate in a propagation chamber (and then transplant), it's much easier to germinate your seeds in the pots in which they'll spend most of their lives. For growers who want ease over perfection, it's an easy way to get plants started.

The second reason you'd choose to germinate directly in the soil is if you're growing autoflowering plants. Due to their autoflowering traits, these plants don't have much chance to recover from stress and damage (whereas photoperiod plants can veg for longer). Transplanting can damage roots and stress plants, which can have negative consequences for autos, stunting growth and yield. So, generally, it's safer to start autos in their final pots and avoid transplanting them.

What Kind Of Soil Is Best For Cannabis Seeds?

Regular, high-quality potting soil mix works well. However, you'll want to avoid growing medium with a very high nutrient concentration. For instance, growers who use a coco mix tend to dig a hole and put soil in the hole before germinating. This is because the coco mix is damaging to young plants.

Seedlings require minimal nutrients to start growing and are particularly sensitive to synthetic nutrients. Therefore, a high-quality organic soil is best. When soil is organic, it's comprised mainly of plant material and won't damage young plants, as these nutrients affect roots differently.

You should also use a medium with good water retention, as moisture and humidity are critical when triggering germination in cannabis seeds.

How To Germinate Cannabis Seeds In Soil

Germinating your cannabis seeds in soil is straightforward. As long as you're careful and the seeds are from a reputable seedbank, germination rates will be high, and the resulting plants will be healthy and productive.

Equipment

• High-quality soil
• Cannabis seeds
• Pot/propagation chamber
• Water
• Heater (optional)
• Tweezers (optional)
• Cling film (optional)
• Thermometer (optional)
• Hygrometer (optional)

Instructions

1. First, you need to fill your pots or propagation chambers with high-quality soil. You don't want to make it too compact, so fill them, but there's no need to compress the soil.
2. Once the soil is in, you need to scoop out a slight indentation for the seed. This should be around 2cm deep and about the same width—it needn't be too deep!
3. Now, thoroughly clean your hands or use tweezers, and place the seed in the indentation. It's possible to transfer disease to seeds, which will either stop it from germinating or kill the seedling soon after it sprouts, so good hygiene is essential.
4. Once in place, lightly cover the seed with soil. Do not compress.
5. Water until the soil is wet, but not soaked. Seeds germinate based on moisture content, so dry soil won't work.
6. Leave to germinate. If using a propagation chamber, then put the lid on. If germinating in the final pot, you can stretch cling film over the top and poke several holes. This will help to keep the humidity high and improve the chances of germination. Ideal temperatures are around 22° and 25°C. You can use thermometers to monitor the temperature and hygrometers to monitor the humidity, though this isn't necessary.
7. Wait roughly 3–10 days for germination to occur. Old seeds can take longer than this, but it is very unusual. Most seeds will germinate within a few days.

Hints And Tips For Germinating Cannabis Seeds In Soil

The following tips will help you to optimise the germination process and ensure the best possible results:

• The perfect daytime temperature is 23°C and the ideal nighttime temperature is 17°C.
• Soil pH level should be around 6.0–7.0.
• Relative humidity (RH) should be 70–90%.
• Though no specific lighting is necessary, seedlings are thought to favour fluorescent lighting (cool white code 33).
• Minimise seed handling and ensure hygienic practice throughout all of the stages outlined above.

Aftercare For Seedlings Germinated In Soil

Once you've followed the above steps, you can mostly leave seeds to themselves. The three main factors to monitor are temperature, humidity and moisture. Usually, the soil will retain enough moisture without extra watering. However, if you notice the humidity dropping or the soil drying out, you can water it again.

Otherwise, let seeds do their thing and accept that however good your practice is, there will always be some that simply don't germinate. Once seeds have germinated, you'll have newborn seedlings in your care. The first week or two are particularly sensitive, so be careful!