Found a random seed lying around, but not sure whether it's cannabis?
Knowing what a healthy cannabis seed looks like is important so you don't waste your time trying to grow a dud seed.
In this article, we'll look at the general appearance of cannabis seed, and how you can test them to make sure they are good to grow.
What do healthy cannabis seeds look like?
First, let's discuss what a healthy cannabis seed should look like.
Color
Cannabis seeds come in several natural colors - black, dark brown, red-brown, or gray. Good quality cannabis seeds often have a shiny, waxy coating on them. Seeds with these dark, rich colors and a subtle shine are ripe and ready for germination.
However, you may also find cannabis seeds that are white, yellow, light green, or other pale colors.
Lighter-colored seeds were likely harvested too early. They weren't given enough time on the plant to ripen fully and develop. These paler cannabis seeds may still sprout, but they'll generally be of lower quality.
Tiger stripes
Quality cannabis seeds often have subtle markings called "tiger stripes" or dark spots. These markings may not be visible to the naked eye, but they indicate a fully developed, high-quality seed.
Under magnification, you can look for these tiger stripe patterns or speckles on mature, healthy cannabis seeds. Their presence is a good sign that the seeds reached peak ripeness before harvest.
Size & Shape
Cannabis seeds have a unique shape. They are oval, have the shape of a drop, and are small in size. On average, a cannabis seed is about 2 to 5 mm long and 2 to 3 mm thick. If you want to know what you can expect in advance, then we can advise you to take a look at the seeds of a tomato.
Shell & Texture
A well-ripened cannabis seed had sufficient time to harden its shell. Healthy cannabis seeds, therefore, have hard, smooth skin without cracks. You can test the hardness of the shell by taking the seed between your fingers and applying gentle pressure. Immature seeds will easily crack or crumble, while qualitative cannabis seeds won’t damage.
Note: the moisture from your fingers can damage the seed. Please use linen gloves to prevent this.
How to test your seeds for quality
1. Float test
An easy way to test if a cannabis seed is still good is the "float test" in a glass of water.
Steps for Float Test:
- Place your seed in a glass of water.
- If the seed sinks within 2 hours, it's good to go. Seeds that sink have a higher chance of germinating than floaters.
- Seeds that still float after 2 hours will probably not germinate.
Important: Please remember that this float test is not 100% accurate. It just provides you with an indication. Also, once soaked in water, the seed's germination process will activate. So only do this test if you plan to grow your seeds immediately, keeping them in storage
2. Visual Inspection
We mentioned earlier that the color of cannabis seeds could indicate how healthy they are. Light-colored seeds won't often grow well because they aren't fully developed. However, there are other ways to tell a cannabis seed's quality aside from its color.
Here are some tips for visual inspection:
- Wrinkled texture: Wrinkled or shriveled seeds have likely lost moisture and may be less viable. Smooth, plump seeds are a better bet.
- Cracks or splits: The seed coat is a developing plant's first line of defense. If there are visible cracks or splits in it, said the defense has been compromised. In most cases, these flaws mean that the seed can't fully germinate.
- Mold or discoloration: Avoid seeds with any visible mold or unusual discoloration. These often indicate fungal growth or improper storage, harming the seed's viability.
- Firm texture: Gently squeeze the seeds. They should feel firm and solid, not soft or pliable. A soft seed usually means there's some sort of internal damage or moisture that can hinder germination.
3. Germination test
You can also check the health and legitimacy of your cannabis seed with a simple paper towel test.
What you'll need:
- Cannabis seeds: About 10-15 seeds to represent the batch
- Paper towels: Absorbent and unbleached paper towels would be best
- Plate or tray: Any shallow container that can hold a damp paper towel
- Spray bottle with clean water
- (Optional) Ziploc bag: To create a mini greenhouse environment
Instructions:
Step 1: Lightly dampen the paper towel. Don't soak it completely, as excess moisture can cause seed rot. Then, lay the dampened paper towel flat on a tray or plate.
Step 2: Place the seeds evenly on the damp paper towel, leaving enough space between them for individual observation.
(Optional): Fold the paper towel to cover the seeds loosely, preventing them from drying out. If using a Ziploc bag, seal it partially to maintain humidity while allowing air circulation.
Step 3: Place the tray or bag in a warm and dark area. Make sure the temperature in that location is consistently warm (around 70-80°F/21-27°C). Use a heat mat if you live in a cooler environment.
Step 4: Spray the towel when it starts to dry so the seeds don't dry out. Check them every day. Look for signs that they are starting to germinate.
What to Watch For:
- Taproot: After 3-7 days, you should start seeing most or all of the seeds sprout a white taproot, followed by a small green shoot
- Uniformity: Most seeds in the batch should germinate within a similar timeframe, indicating good overall quality
If 80% or more of the seeds you placed on the paper towel grow their taproot and shoot within the same timeframe, congratulations! You've got some high-quality seeds.
If 50% or less of the seeds didn't sprout taproots within the same timeframe, you've like got a bad batch. More so if none of the seeds sprouted.
Remember: While this test provides valuable insights, it's not foolproof. Certain factors like genetics and seed variety can influence germination times. However, a consistently low germination rate across several seeds is a strong indicator of potential issues.
Frequently Asked Questions
Does the cannabis strain affect the seed's color?
Yes, the color of a cannabis seed may indicate what strain it is. For instance, White Haze seeds are lighter than other strains. But they can still be very potent. Remember that many things affect the quality of the cannabis seed, like growing conditions and genetics.
So, while seed color is one of the cues you can use to tell a seed's quality, it is far from the only one.
Can you determine the sex of the cannabis seed just by looking at it?
No. It is impossible to tell the sex of a weed seed by looks alone. Cannabis seeds don't show any indication of their gender until they sprout. You can tell which ones are male or female based on the appearance of pollen sacs (males) or hairy pistils (females).
Until then, the sex stays hidden - even with the help of a microscope or magnifying glass.
Does the size of the weed seed matter?
Seed size doesn't show how good a cannabis plant will be. Bigger seeds have more stored energy to grow fast at first. But that doesn't mean healthy plants later. Small, mature seeds can still grow strong. Large seeds can be weak if damaged.
Look at other things like color and feel. It's not just size that matters for quality. Good seeds come in all sizes.
Conclusion
Picking healthy cannabis seeds is important for good plant growth.
Good cannabis seeds often have tiger stripes, a teardrop shape, and a smooth texture. They are dark-colored with a hard, waxy shell. You can also run a float test or germination test to check seed quality.
