How To Precrack A Cannabis Seed

Cannabis is a plant that requires special care for everything, from germinating a seed to harvesting and drying. When a seed is grown with all the organic nutrients it needs and intense sunshine, it can produce a shell that is extra tough. Genetics also play a role in how thick a shell can be.

cannabis seeds

Winning seeds are rich in color with a smooth exterior and good tiger striping

Oftentimes, you may find that when you drop seeds in a cup of water, they do not sprout even after 48-72 hours of soaking (the average time it takes for a cannabis seed to sprout). You can either precrack a seed prior to exposing it to moisture, or as a last resort, you can crack seeds that have been soaking and have failed to sprout. This allows you to save and start seeds that may not have sprouted otherwise.

Here’s how to precrack a seed:

Step 1: Float. Place the seeds in a small glass of water, preferably 6.0 Kangen (beauty) water. Float until the seeds sprout.

Step 2: Prepare for cracking. If they fail to sprout after 48-72 hours, crack them open. Using a pair of tweezers or needle nose pliers, line the seed up with the bottom (flat end) of the seed pointing towards the inside of the tweezers (and you) and the tip (pointed end) of the seed pointing out and away from you. This technique allows only one seed to be popped at a time.

Step 3: Apply gentle pressure. Once you have the seed properly positioned, gently apply pressure until the seed barely cracks open. This requires a delicate touch. If you squeeze the seed too hard, it will burst, causing the seeds' internals to explode out of the shell, killing it. The shell should open, however, you should not see any white or internal parts coming out of the shell. This can happen in an instant, so be careful.

germinating cannabis seeds

Drop seeds into a cup of water to allow them to germinate

Step 4: Place in a paper towel. Lightly wet a paper towel, making sure to squeeze out any excess moisture. Again, 6.0 Kangen water is recommended. If the paper towel is too wet, the seeds will mold and die. If it doesn’t have enough moisture, the seed will either not sprout or will also die, especially if it’s precracked. Make sure to place no more than 10-12 seeds per paper towel. It’s best if you fold the paper towel in half and then line the seeds along the middle, inner part of the paper towel. Since the seeds will sprout tails that can easily become tangled with one another, it’s best if there’s a little space between the seeds. Tuck the seeds in the paper towel by folding the ends slightly; then move onto Step 5.

paper towel tech

Germinating a seed in a damp paper towel is easy and effective

Step 5: Place in a Ziplock bag. Gently place the paper towel in a Ziplock bag, making sure no seeds fall out of it, and then close the bag. It’s recommended that you leave a little bit of air inside the bag. You don’t need to blow into the bag or anything, simply don’t squeeze all of the air out of it. Place the bag on a counter or someplace that is easy to check on and at a temperature between 70-76 degrees Fahrenheit. If the seeds are kept in a space that exceeds or drops below those temps, they are likely to either not sprout (too cold) or have an increased probability of becoming males (too hot). If your environment is too cold, place the bag on a heat mat.

Step 6: Wait. Let the seeds rest and do their thing for the next 12-72 hours, in which time they should sprout and grow taproots that are 2-3” in length. Check on them every 8 hours or so, making sure the paper towel doesn’t dry out. If you notice it becoming dry, lightly mist with water. Most healthy seeds will be ready to plant after 2-3 days in a paper towel; however, older seeds and seeds with thicker shells can take a little longer; 4-5 days. As long as there is no mold, the seeds still have a chance to sprout. If you don’t see any change or growth after a week, the seeds will likely not sprout.

Step 7: Prep the sprout for planting. Ideally you wait until the seed shell has popped off. If it is still attached when the taproot has reached the desired length, gently remove it. It works well to separate the seed shell like chopsticks; place a thumb on each side of the shell against the tap root and open the shell gently. Once the shell is removed, look for a little sleeve covering the leaves at the top of the sprout. With a careful touch, pull it off. The sleeve wraps the leaves together, and once removed, allows them to freely grow. If the tail of a seed has grown into the paper towel, rip the paper towel around the taproot, being careful not to damage the root, and plant the seedling with the small piece of paper towel still attached.

seed sleeve

The sleeve wraps the leaves together, and once removed, allows them to freely grow

Step 8: Plant the sprouts in soil. After you see a nice taproot 2-3” length, carefully plant the seed in a small pot with soil. Place it under a LED light and expose it to an 18/6 photoperiod.

delicate seedling

Seedlings are delicate; be careful when handling them

Step 9: Water as needed. Water the seedling as needed. Seedlings require less water than you think and can easily become overwatered due to not having much of an established root system to help soak up water. They can also easily dry out in rooms that have low humidity, high temperatures, or intense light exposure. It’s best to water seedlings with 6.0 Kangen water and a pump sprayer, which will allow you to gently mist water at the ideal pH level. This helps ensure no overwatering occurs.

Get Cracking

It can take a little practice to get this technique down, but is effective and can help sprout seeds that might not grow otherwise. Happy cracking!