Immature cannabis seeds, on the other hand, tend to be green and have a soft outer shell that breaks when any kind of pressure is applied to it.
We do not recommend taking the size or shape of a seed into consideration as a sign of its quality. Some strains simply produce smaller seeds than others, and sometimes the same plant can produce seeds of different sizes and shapes. Never discard a seed just because it is smaller or of a different shape than another one.
Can You Tell The Sex Of Cannabis Seeds From Their Appearance?
This simple and cost-effective method is a great way to tell the good genetics from the bad; they will sink or swim, literally. Seeds that remain buoyant on the surface are more than likely of poor quality and are to be discarded. Seeds that sink to the bottom like a botanical cannonball are probably healthy and should be germinated.
Keep in mind that the simple process of packaging and storing cannabis seeds can also affect their appearance. Abrupt changes in humidity, temperature, or light exposure can make some seeds appear darker or lighter than others, but ultimately have no effect on their quality.
It’s important to only conduct this test if you are planning to germinate the seeds immediately afterwards. The viable seeds that sunk to the bottom of the glass will have taken in water, crossing the membrane of the seed and signalling that it’s time to come to life—activating germination.
When I water* the soil, it tends to move some soil over the seed. I label my cup and place it in a dome for high humidity and added warmth (shown next to a clone). Position a small grow light above the dome and have the timer the same as your 18 hour garden clock. We want some air, moisture, warmth and light right now.
The cannabis seed sinks when it absorbs water (24 hours). When you return the next day and uncover your glass, you may notice that the seed sank to the bottom.
Keep the soil moist, but not wet. there is a difference. After my initial watering, I do not water* it again for 2-3 days, and then I am spraying water* over my cup of soil.
Giving the seedlings a mild nitrogen mixture in your water* will help vigorous, healthy growth at this stage (if your soil does not compensate in this important area). Be careful! They are still young and very impressionable.
Once your seedling has 5-7 growing days in the cup, you can transplant it anytime to it’s larger container. Make this large enough for the life of the plant (I use 5 gallon containers) I never want to run out of room (soil) at the point of flowering.
I use a solo cup and slice four slits in the bottom for good water drainage and added aeration. It also makes the transplant very easy.
Sometimes, as in this example, the seed shell stays attached while the seedling works it’s way upward and fights to exist.