Feminized Hemp Seeds: Hemp Growers Make Allies with Geneticists

Published: May 29, 2022

Uniquely high quantities of CBD and CBG oil are produced in the flowers of female hemp plants.

Uniquely high quantities of CBD and CBG oil are produced in the flowers of female hemp plants.

With the 2018 Farm Bill legalizing the commercial production of hemp, enterprising farmers have discovered yet another opportunity to profit. 

Research experts have confirmed that the female hemp plant produces higher quantities of CBD, the prestigious phytocannabinoid. As a result, feminizing hemp seeds presents an opportunity to make the most of every harvest. 

This breakthrough might also prove to be the solution to the long-term problem of cross-pollination, which also affects phytocannabinoid yields in hemp harvests. 


If you are invested in hemp cropping, you probably already know that “feminized seeds” are much more expensive than regular ones. So, are they really worth it? Why are ordinary female hemp seeds not a practical choice for an all-female harvest? 

In botany, some plants are dubbed “hermaphroditic,” bearing male and female traits on the same flower. So, these sorts of plants self-pollinate.

On the other hand, there are the “dioecious” plants. These can either bear male or female characteristics and therefore need external agents for pollination – Hemp is an example of a dioecious plant. 

Michael Scheffel, Managing Director of Policy and Standards with the Canadian Seed Growers’ Association (CSGA), said: 

“Hemp is naturally a dioecious plant, meaning it has separate male and female plants. A normal cannabis variety or hemp variety will produce approximately 50% female plants and 50% male plants.” 

Note: In high-stress periods, hemp can turn hermaphroditic. 


Simply put, feminized hemp seeds are cultured to grow exclusively female hemp plants. These seeds are modified to eliminate the male chromosomes, drastically reducing the likelihood of producing male hemp plants. 

As a result, it enables maximized profits and decreased losses. 

Analytical reports suggest that experienced hemp farmers can earn up to $40,000 per acre of hemp. This means a 20% decrease in phytocannabinoid yield (often from cross-pollination) could amount to an $8,000 loss. 

Therefore, to produce a female-only harvest, masculinized female plants are a necessity. 


“At a certain stage of development, you want to get the female plant to produce male flowers and produce pollen,” Scheffel says. “But, this is still a female plant, and all the pollen it produces will only have XX chromosomes.”

So, fertilizing a female plant with pollens of chromosome type XX, will produce only female plants. However, these results might vary per certain conditions, such as genetics and environmental factors.

Now, though the goal is to create 100% female plants (monoecious types), John McKay, Chief Scientific Officer of New West Genetics and professor of plant evolution genomics at Colorado State University, said that just a few companies get it absolutely right. 

Hence, the term “feminized seeds” is not exactly scientifically accurate. Instead, “monoecious” is more appropriate since the plants are usually female with pollen or male flowers. Then, there is the gender skew, which is a significant deviation from the more common 50:50 ratio of males to females.


Having understood what these seeds and their flowers are all about, the next question to be tackled is: “how are hemp seeds feminized?”

There are two ways of feminizing hemp seeds: the natural way that involves rodelization and the artificial way that incorporates silver in the process.

“Applications that reduce the ethylene level in tissues or antagonize the action of ethylene causes the formation of male flowers instead of female ones” — Paraphrase, Byers et al., 1972.


This method involves subjecting a specific female plant, one which is  known to contain hermaphroditic traits, to increased stress. The action causes a slight interruption in its flowering cycle, prompting a much longer flowering period. Eventually, the plant is spurred to produce male flowers in response to the genetic threat. 

With the elongated flowering stage, the female plant develops pollen sacs from the male flowers, which can be harvested and applied to a pure female plant (one without hermaphroditic traits). The seeds obtained through this process are considered ‘feminized’ seeds.

However, this process might not work all the time. Since some hemp plants are hypersensitive to hermaphroditism, the pollen of the stressed female plants might transfer the intersexual traits to the seeds.


This method is generally more effective. The practice follows the same ‘stress’ method above but involves spraying the female hemp plant with colloidal silver every day after the plant flowers. The application of silver slows down the production of ethylene, a hydrocarbon gas that helps the plant through the flowering stage. 

As a result of the constraint, the female hemp plant starts producing male flowers with pollen sacs, which can then be harvested and used to flower new female hemp plants to produce feminized seeds.

Although several other compounds can be similarly employed, colloidal silver is, by far, the easiest to source and to make. It is also non-toxic, non-caustic, and easy to purchase.


At this juncture, creating a dominant female hemp population seems like a breeze. However, there are a few challenges with this method:

The CBD-THC Conundrum

One of the primary purposes of developing an all-female population of hemp is for the much higher level of CBD (or other desired cannabinoids). However, as the CBD rises, so do theTHC level. This could quickly become a legal problem. 

“Depending on the genetics, there’s a strict correlation between THC and CBD. To still get a high level of CBD, but also keep the THC below the 0.3% level, you really can’t take these hemp plants past somewhere between 6-8% CBD. The higher it goes with CBD, the more it tends to drag up the THC level, which causes the plants to get hot,” says Scheffel. 

Not Your Regular Seeds

Another difficulty is the relative high cost of these seeds. This situation is, however, understandable due to the increased investment made into producing these seeds.

According to McKay, “People were selling it for tens of thousands of dollars per pound, especially during the CBD Gold Rush era.”

Taking into scope the overall cost of production, these seeds might cause anyone looking to start a large-scale venture with a stable supply chain to think twice before making the move. 

There is also a risk of sourcing low-quality feminized hemp seeds, which might yield hermaphroditic plants. 


Feminized seeds are fast becoming a staple in the hemp industry since most farmers agree they are a worthy investment. Here are some reasons the United States’ hemp industry appreciates its presence:

1.Less Worry

By choosing feminized seeds, growers would not need to worry about male hemp plants pollinating their female flowers and reducing cannabinoid yield.

2. Better Forecasting

With feminized seeds, it is a lot easier to predict crop yield and profit levels. Better predictions permit a much more effective planning and negotiating process.

3. Higher Profits

The most appealing part of using feminized seeds is the higher chance of increasing profits. 

With regular seeds, farmers have a 50:50 chance since they usually grow to have a balanced amount of male and female flowers. In this case, the grower might need to destroy roughly half of their crop during planting; thereby, denting their ROI. 

On the flip side, feminized seeds have a roughly 99% chance of germinating into CBD or CBG resin producers.

4. Lesser Work (in some areas)

Having more female plants, as desired, means less work with flower assessment and culling of male plants. Therefore, more time and effort are focused on other production areas.


Many hemp companies are eager to advertise and offer feminized seeds to growers for the possible mouth-watering profits, but not all can deliver on the lofty promises of high feminization rates. So, for a better chance of getting actual feminized seeds, it is vital to take these carefully calculated steps:

  • Make your purchases from reputable feminized seed companies. 
  • Ensure that the company has a high feminization rate, must have been around for a few years, and has good customer reviews.
  • Finally, ensure the seeds are certified and tested to stay above legal waters and maximize profits.

Author: Deborah Agboola, Content Editor at Mariposa Technology

About Mariposa Technology

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The mission of Mariposa Technology is to deliver simple, point-and-shoot scientific testing solutions utilizing handheld Raman spectroscopy and proprietary data powered by advanced mathematics and algorithms, starting with hemp and other varieties of cannabis.

Our vision is a world of agricultural testing that is user friendly, free of solvents and chemicals, with quick and consistent results, all while meeting or exceeding the highest industry standards.

Our technology will bring the power of laboratory-level testing into the hands of farmers, researchers, regulators and more. PAMAP (Predictive Analytical Modeling Application for Plants), our first commercial offering, will empower the hemp and cannabis industry to optimize their crops, delivering real-time precision farming data at the click of a button.

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