How to Harvest Your Own Cannabis Seeds

Congratulations! You’ve mastered the art of growing your own marijuana plants from seed and clone, and you’ve succeeded in bringing in a number of fruitful harvests. Perhaps you’ve even found a couple of strains along the way whose plants produce such a scrumptious bud that you have a new goal in mind: to produce your own cannabis seeds and have a truly home-grown harvest for your next crop.

Woah There, Tiger

As with most forms of sexual reproduction, in order to produce marijuana offspring (or cannabis seeds), you need a male and female plant. A male plant can produce pollen, which acts as a fertilizing agent in female plants, around two weeks before a female plant is ready to receive it. Because of this difference in sexual maturity, it is important to keep your male plant alive and thriving as you wait for your female plant to reach maturation. You can do this by pruning the male’s quick-growing buds and allowing the slower-growing flowers time to mature at a more leisurely pace.

Cannabis Seeds

When the Moment’s Right

Once the female plant has begun to produce flowers of a decent size with a number of long hair-like pistils, she is ready to receive the male plant’s pollen. There are two ways to approach the actual pollination stage: you can stick male and female together and let nature take its course, or you can manually pollinate specific female branches.

Au Naturel

The first option is the easiest up front, but will ultimately take the most effort on the part of the grower. Essentially, when both male and female plants have reached maturation, you should place them next to each other and shake the male plant. This will encourage a release of pollen, which will spread around the air and land throughout the female plant. Repeat this step once or twice a day for two days to ensure fertilization.

If the female plant is fertilized this way, there is no way to control how many cannabis seeds are produced, or where on the plant they come from. When it is time to harvest, you will notice that most, if not all, of your bud has a plethora of seeds buried within. In addition to being a lot of work, this mass production of seeds can be very wasteful. Growers may not have enough room to plant all of the seeds, and the leftover bud will be less robust due to the female plant’s energy being put into seed production.

Doing It by Hand

The second, more popular option is to pollinate specific branches on the female plant with pollen from the male. Before you get down to the dirty deed, you need to put in some prep time for both the male and female plants. First, turn off all fans and air circulation devices. For the female, prune the lower branches as well as the fan leaves that surround the branch or branches that you wish to pollinate. After preparing the female plant, clip off some of the more attractive and full-looking flowers from the male plant and place them in long paper wine bags (at least one good-sized flower per bag).

Now it’s time to pollinate. Carefully slide the paper bag with male flower around the prepared branch of the female plant. When the entire branch is covered, tightly close the end of the bag at the base of the branch using a zip-tie, string, or tape that will peel easily (such as masking tape or painter’s tape). Once the bag is secured, shake it strongly to encourage the spread of the pollen. Over the next couple of hours, repeat the shaking process one to two more times.

When removing the bag after pollination, be careful not to jostle the branch or the flower inside the bag. This could lead to accidental fertilization of other branches on your female plant (or surrounding plants). Although this requires more specific and detailed work up front, you will thank yourself later. This method of fertilization will provide you with enough seeds to plant for your next crop, while not overwhelming your female plant with seeds in every bud.

Bun’s in the Oven

Mature Female Marijuana PlantNow you play the waiting game. Continue on caring for and pruning your growing plants, and keep an eye on your female for the signs of fertilization. Once pollinated, most cannabis seeds will fully ripen within 4 to 6 weeks. You should expect to leave your fertilized flower on the plant longer than the bud that is not fertilized.

A ripened seed is structurally sound and dark brown or tan in color, often (but not always) with obvious stripes along the outside. The harvesting process is relatively simple. Simply dig into the fertilized flower and pull out the seeds. Don’t worry about messing up your bud harvest: female flowers that have been fertilized expend a lot more effort into growing seeds than producing THC, so the fertilized bud will not be nearly as potent to consume as the rest of the plant. (Of course, you can still use the seedless fertilized flower for shake, melting into butter, or making other edibles.)

The Circle of Life

Once you harvest your cannabis seeds, the next step is to plant them and start the entire process over again. If you’re not ready to start a new crop just yet, don’t worry. You can freeze the seeds and they will retain their ability to germinate.


Article by: Daphne Eccleston