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Case Study: Propagating Cannabis Seeds by Floating

June 03, 2019

  • Why Float Cannabis Seeds?
  • Floating Cannabis Seeds

Why Float Cannabis Seeds?

In general, growing cannabis from seed can offer the opportunity for growers to possibly create something new which can be exciting and different. Besides genetics, phenotypes based on the grow environment can create different alterations of the same cannabis strain (Conviron, 2017). An individual can easily purchase seeds online or by pollinating and hybridizing one’s own seeds for use. Cannabis growers may find more success by first floating or soaking their cannabis seeds in filtered water, than planting directly into a growing medium.

Cannabis Seeds Floating In Water

Tesseract (Andy’s Blue Dream x White Lemon Stomper) cannabis seeds floating in filtered water. Genetics are from Pink House Colorado. Image taken by RMK.

The germination of cannabis seeds depends on the right amount of heat and moisture (NGA, 2018). Since viable cannabis seeds float on the surface of the water, they are able to retain the proper ratio of moisture and air. Seeds that do not float may be sterile or underdeveloped. When you roll the seed in your hands prior to floating the seed, it should be firm and brown with the occasional dark stripes in appearance. Immature cannabis seeds appear green or sometimes white and as stated above they will sink to the bottom when you attempt to float them.

Floating Cannabis Seeds

Properly floating cannabis seeds is as easy as placing these seeds in warm filtered water with a ~7pH in a container that is covered from direct light. When the tap root is about ¼ to ½ inch in length, you know the cannabis seeds are ready to be placed into their growing medium.

Cannabis Seeds Taproots Exposed

Tesseract cannabis seeds with taproots popping out. Check out the seed hulls, they are a dark brown color with several dark spots and stripes. These seeds were soaked for a 24 hours. Image taken by RMK.

These cannabis seeds were floated in 8oz white paper cups covered by a pot tray. These cups were then placed under a T5 light approximately 1ft away from the tops of the cups.

Cannabis Seed Standing Upright

A Tesseract cannabis seed with a taproot popping out is being placed standing up into a small cup of presoaked promix for planting. Image taken by RMK.

Within 24 hours these seeds had a success rate of 100% with all seeds showing tap roots and being placed into a different set of 8oz paper cups that were full of presoaked promix. The promix was only immediately presoaked using filtered water with ~7pH. The cannabis seeds were placed with taproots sideways or with the seed hull standing upright and the taproot pointing downwards about ½ to 1” inch deep into the promix growing medium.

Cannabis Seeds Sprouting

The small cups holding the seedlings are separated to easily identify several different strains in the large white tray. Image taken by RMK.

After a total of four days since the cannabis germination started a majority of the cannabis seedling should begin to sprout from the surface of the growing medium.

In conclusion, floating cannabis seeds can be beneficial for cannabis seed propagation for several reasons. Finding viable seeds and ensuring a higher success rate of germination, even if it may take longer for some seeds, are two main reasons why a cannabis grower may want to try floating cannabis seeds as a means of propagation instead of other methods which are also perfectly acceptable.


  1. NGA - National Gardening Association. (2018). “Propagating Amaryllis Seeds by Floating”. National Gardening Association.

  2. Conviron. (2017). “Cannabis: Propagation. Cloning Methods For Commercial Growers”. Conviron.

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