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harvesting cannabis seeds

Learn every step of the cannabis harvest and post-harvest process.

There’s another way to detect when harvest is closing in. Some basic knowledge of plant anatomy can help growers spot these shifts. Certain parts of the cannabis plant begin to change in appearance as they ripen. Rather than relying on guesswork alone, you can use these botanical landmarks as indicators. First, you’ll need to get familiar with certain tissues, glands, and organs, so you know what to look out for.


In general, every strain has its own estimated flowering time. This statistic can be useful in preparing for harvest, but it’s not always accurate. Environmental factors can extend or shorten the blooming phase. Indica strains mature faster and will flower for 6–8 weeks, whereas their sativa counterparts typically take 8–12 weeks.

A calyx is the first part of a cannabis flower to emerge from the node. This structure starts off life as a bundle of small leaves and eventually unfolds into fully formed flowers. They remain at the base of each bud and house the reproductive organs. Calyxes are the most resin-rich part of a cannabis flower, and their role is to provide structural support, ensuring buds aren’t blown away during high winds or pecked off by winged predators.

Have you ever smoked some dank-looking weed only to find it tears your throat apart? This is the result of uncured cannabis. Curing adds significant time to the end of the growing process, but it adds so much value to a harvest. It’s a prolonged drying process that removes moisture from the interior of flowers, something that drying alone cannot achieve.

If you meant when to harvest seeds from cross-pollinated Marijuana plants, then the seed will fall from the flower by itself once it is mature and ready to germinate into another Marijuana plant. Usually, as a best practice to harvest Marijuana seeds, some growers wait for the whole flowering cycle to end just as if they were harvesting the flower.

You can also judge the ripeness of the Marijuana by taking a look at the trichomes; or little hairs/crystals on the flowers and surrounding areas of the Marijuana plant. If they are transparent its still too soon, if they are milky white they are ready and if they turn brown they have become over-ripe. It is also advisable to follow the instructions to harvest Marijuana seeds on the packet since most reputable breeders also have a tried and tested flowering time for optimum ripeness, potency and flavour of a Marijuana strain.

After the whole process of germination, growth and flowering, a lot of growers ask themselves when to harvest Marijuana seeds. Usually, the breeders will include a suggested flowering time for each strain, but as a rule of thumb, Indica marijuana plants harvest in 6-8 weeks while Sativa Marijuana plants take 10-12 weeks.

Look for these signs for when to harvest Marijuana seeds

You might find our FAQ Submission How Do I Harvest My Plant? useful

It’s important to continually practice germination testing to be sure your stored seeds haven’t lost all viability. To test this, periodically plant a seed and document its ability to germinate.

Male cannabis plants will produce pollen several weeks into their flowering cycle. Once their pollen sacs have opened up and released, the plant will begin to senesce and eventually die. It is important to collect pollen right as the sacs are beginning to open up, as this is the time pollen is most viable.

Moisture is a death sentence for pollen viability. Because of this, many breeders opt to mix flour into their pollen at a ratio of 4:1 (flour to pollen) when storing it long-term. This additional step will help keep pollen dry for a longer period of time.

Seed and Pollen Storage

Separate or sift seeds over the screen to remove any unwanted plant matter from the seeds themselves. Brush off the seeds—they should be completely free of any remaining plant material such as leaves, stem, or trichomes, as these elements put seeds at a higher risk for contamination and spoilage during long-term storage.

To release the seeds, simply break up the dried buds over a screen and they will fall out. You can release the seeds en masse by rubbing the flower between your fingers and lightly breaking it apart.

The best way to harvest pollen for storage is to remove an entire male flower cluster and place it in a sealed storage container for several days. After the cluster has dried, place it over a micron screen with parchment or wax paper underneath, and give it a light shake. This will allow the pollen to separate from any remaining plant matter and fall through the screen and onto the wax paper.

For a cool environment, store seeds in either the refrigerator or freezer. Seeds need a consistent temperature without fluctuation to remain dormant long-term.