How to Germinate Cannabis Seeds

Germination is the crucial first step in cultivating cannabis, where the seed awakens from dormancy and begins developing a root and its first leaves. The paper towel method is very popular due to its simplicity, high success rate, and the ability to directly observe the emerging taproot.

1. Preparation and Material Selection

Seed quality: Use only high-quality, mature cannabis seeds. These are typically dark to light brown, often with a tiger-like pattern. Pale or greenish seeds are usually immature and have poor germination rates.

Water: Ideally use distilled or reverse osmosis water to avoid chlorine or minerals that may interfere with the germination process. Alternatively, you can boil tap water and let it cool.

Paper towels: Use unprinted, tear-resistant kitchen paper. It must be absorbent but still maintain its structure when wet.

Tweezers: Use a pair of tweezers that you have disinfected with a sanitizing spray beforehand.

2. Setting Up the Germination Chamber

Layering: Take a clean plate and place two to four layers of paper towels on it. Moisten them carefully until fully saturated. Gently squeeze out excess water so the towels are damp but not dripping. Too much water can “drown” the seeds by blocking oxygen.

Placing the seeds: Place the seeds at least 2 cm apart on the lower paper towels. This prevents mold transmission and makes handling easier later.

Covering: Place another two to four layers of moist paper towels on top. Ensure each seed has direct contact with the paper.

3. Creating the Optimal Germination Environment

Darkness and humidity: Place a second plate upside down over the first, or use a plastic container with a lid. This blocks light and stabilizes humidity.

Temperature: The ideal germination temperature is consistently between 23–25 °C (73–77 °F). A warm location such as the top of a router or a heating mat works well. Temperatures below 20 °C slow down germination, while temperatures above 28 °C may damage the seeds.

4. Monitoring and Care

Daily checks: Inspect the setup daily and lift the top plate gently.

Moisture management: The paper towels must remain consistently moist. If they begin to dry out, lightly mist them with lukewarm water. Ensure no standing water collects at the bottom of the plate.

Germination time: Most cannabis seeds germinate within 1–5 days. Older or more stubborn seeds may take up to 10 days.

5. Transplanting the Seedling

Ready for transplanting: The seed is ready once the white taproot (radicle) is about 1–2 cm long. Don’t wait too long, as the root can grow into the paper towel.

Caution: The taproot is extremely delicate. Use sterile tweezers or hold the seed gently by the shell. Never touch the white root directly.

Planting: Plant the seedling root-down into a prepared growing medium (e.g., seedling soil or coco). The seed should sit about 0.5–1 cm below the surface. Lightly cover the hole and water gently.