How to Germinate Cannabis Seeds in a Paper Towel (Step by Step)

Step 1: The 15-hour dark soak

Drop your seeds into a cup of room-temperature water, 65-72°F, and put the cup somewhere dark and warm. Fifteen hours is the sweet spot. The soak softens the shell and signals the embryo that it is time to move.

Most seeds sink within a few hours. Floaters are not automatically duds — give them a gentle tap with a clean finger and keep going. Do not push past roughly 20 hours, because a long soak starves the seed of oxygen and stalls the taproot.

Step 2: The damp paper towel

Wet two paper towels and wring them until they are moist but never dripping. Lay the seeds out an inch apart, cover with the second towel, and slide the stack between two plates or into a zip bag left slightly open for airflow.

Keep the whole setup in the dark at 70-80°F. Darkness is not optional — it tells the seed it is underground. A closed cupboard or a drawer near a warm appliance works fine.

Step 3: Plant at a quarter inch

Check once a day and re-mist so the towels never dry out. Between 1 and 4 days you will see a white taproot. Once it reaches about a quarter inch, it goes in the ground.

Plant taproot down, half an inch deep in pre-moistened soil. Cover lightly, never pack. Handle the seed by the shell only — touching the root tip can kill it outright.

What usually goes wrong

Three failure modes cover almost every dead seed: towels that dried out overnight, a room that sat below 65°F, or a soak that ran 30+ hours. Fix those and germination rates on fresh, healthy genetics usually land above 90%.