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How Cannabis Breeders Find ‘The One’

Cannabis is an intrinsic plant species, captivating civilization for millennia. As early humans discovered the beneficial attributes from the multi-purpose plant, the quest to domesticate the species began. When first discovered, cannabis grew naturally, reproducing without man’s intervention.

However, it did not take long before humans began domesticating the species, learning to manipulate the plant to grow in different manners. While some early breeding attempts focused on the ‘bigger is better’ principle increasing size and yield from the plant, others were motivated to improve the psychotropic effects by elevating THC.

In the early days, cannabis breeders from Amsterdam to California dabbled with known landrace strains, producing new genetics with similar traits yet crossed with more favourable attributes. For instance, fibre producers mixed and matched strains that resulted in thicker stalks for textiles. Others learned that crossing one of the original skunk-smelling Afghan strains with a Thai Stick variety produced a hybrid plant with intoxicating THC levels. If those guys only knew what we know now!

Modern cannabis research, especially in the past few decades, has uncovered many of the plant’s beneficial secrets. Discovering the cannabinoids, terpenes, and flavonoids and their contribution to the outcome of a plant has been monumental for cannabis breeders.

Additionally, as plant genetics is now studied more intensely, today’s breeders are privy to an abundant array of characteristics that bring out the best in a cultivar. Taking the ‘best of the best’ is how cannabis breeders find ‘The One’.

How Breeders Determine ‘The One’

Defining potential candidates for cannabis breeding purposes for the first time requires some strategy. Most importantly, the question arises, what are the attributes that will define the strain? Will it display high THC or medical marijuana high CBD levels? Does it offer a fruity smell and taste, or will it deliver an earthy aroma and flavour? Will it be indica or sativa dominant, and how well will the new hybrid strain combat pest and disease?

There are many considerations a breeder must ponder when determining a potential cross.


In today’s cannabis market, demands range from high psychoactive THC cannabis strains to medically beneficial CBN, CBG, and CBD strains. Depending on which of the cannabinoid contributions a breeder wants to produce determines the origins of the parent plants.

Sativa or Indica Dominant

When looking at different strains to determine a new hybrid, breeders search for cultivars that complement each other to produce the plant they envision. While hybrids can be either Sativa or Indica Dominant, a blend of the two sub-species contributes to the growth and outcome of the new strain.

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Flavour and Aroma

The discovery of terpenes in cannabis changed the game for breeders. Thanks to these secondary metabolite’s contributions, there is now a plethora of tastes and smells to choose from. Whether a cultivar exhibits sweet citrus flavours to piney or floral scents, breeders cross certain marijuana strains to overwhelm the sensory channels.


While environmental controls, substrate choices, and nutritional demands differ in every growing situation, high-yielding varieties are a hot commodity. In high-producing cannabis cultivation facilities or large-scale fibre operations, strains must profitably contribute to the operation. One unproductive flip can ruin the balance sheet for these larger companies. Breeders can choose from known genetic thresholds to determine which cultivars offer a lucrative RIO.

Pest and Disease Resistance

If there is one thing all cannabis growers detest, it is pest and disease issues. The battle to eradicate an infiltration of the illusive two-spotted spider mites or a bout of botrytis is one of the worst maladies to overtake a grow room. Fortunately, cannabis genetics determine specific influences in strains that build a robust immune system, helping the cultivar achieve resistance to these nuisance invasions.

Environment Adaptability

Cannabis grew fine on its own for centuries, finding nice sunny spots with plenty of water to live out their life cycle. Through natural selection, they learned how to adapt to their environment and flourish. Once man discovered the little jewel, however, things began to change.

In today’s hot marijuana market, seed companies develop seeds from a plant in a particular region and shipped them to all ends of the world. Typically, the plant’s survival is based mainly on the environment it is grown in, although the genetic disposition of the seed form can also influence its behaviour.

Thanks again to genetic developments, breeders can select parents with strong environmental adaptability traits.

Initiating Reproduction

Once the marijuana breeder determines the parental lineage, the real work begins. Cannabis is a dioecious species meaning there are individual male and female plants. Male reproductive organs are visible through the stamens, which eventually produce little seed pods, while females display their pistils as they enter the reproductive stage.

Cannabis breeders must first grow both parents into the pre-flower stage before the process can occur. Isolating the male parent in an airtight chamber is necessary to collect the pollen and, more importantly, to keep it from drifting into unwanted areas.

Tiny pollen sacs will begin forming as the male proceeds into maturity. Within a short time, the pollen sacks will become enlarged and eventually burst yellow powder in all directions. A knowledgeable breeder will quickly trap the pollen and then apply it to the female parent when she reaches the reproduction stage.
There are several methods used to apply pollen to the female. Simply putting the male plant in the same chamber with increased airflow is the easiest application. Yellow pollen will fly everywhere!

Another method is to sprinkle the fluorescent pollen onto the female plant’s pistil sites as they become mature. Some breeders have one male and several females in the same room.

On the other hand, advanced controlled breeding procedures apply various pollen specimens from different males and use them on one individual female plant. Whichever method is used, strict attention to detail and meticulous record keeping is a must during this step in the breeding process.

How do cannabis breeders find "the one"

Discovering the F1(first generation)

Pollen can be saved and frozen from the male plant while the female(s) F1 progresses through the flowering stage. As the mother plant matures, breeders watch and collect data on the plant’s growth performance. When she finishes off, the final Certificate of Analysis will reveal detailed analytics on the new hybrid. Breeders then determine if it is a viable cross.

If the results are pleasing, breeders then germinate the F1 seeds. The young plants proceed through the vegetative stage for a few weeks before flipping them into the reproductive stage. Depending on the size of the breeding operation, the offspring will present a variety of phenotypes. Obviously, the more plants available for observation reveals the various characteristics of each phenotype.

If there is a wide variety of phenotypes, the plant is said to be heterozygous. On the other hand, a plant is homozygous when it produces a small amount of variation. The homozygous plants display a stronger genetic expression because their offspring inherit distinct genes from both parents.

At this point, some offspring will make it to the next round, and some will not. Cannabis breeders narrow down their search for ‘The One’ at this juncture. Depending on their performance, the remaining F2 generation plants are evaluated for further refining.

Stabilizing the Genetics

There are several methods used for advanced genetic refining. Self-pollination is a means to reduce gene diversity, stabilizing the genetics in the next breeding round. This process helps improve the solidity of the gene pool as it matures into the next phase.

Other breeders may want to influence desirable traits from a particular strain. For instance, if the original male displayed an excellent calyx to leaf ratio, the second cross back to the male’s pollen will amplify those traits. This process is called back-crossing.

For breeders who experience a small variety of phenotypes from a homozygous plant, inbreeding two similar plants from the same phenotype is another option.

While some breeders may be happy with the results after cross-breeding two or three times, others continue the stabilizing process until they finally find ‘The One’.

Start With Good Genetics in the Beginning

The domestication of cannabis throughout the years reveals more options now for breeding purposes than ever before. Unfortunately, at the cost of losing many of the great old landrace genetics. However, advancements in science and technology in the cannabis industry continue to encourage and influence breeding practices, opening the door for further cannabis plant breeding.

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Post author
Charle Thibodeau
Charle’ Thibodeau is a freelance writer with almost a decade´s experience, specializing in cannabis content for the past two years. A strong motivation to educate, inform, and promote the culture surrounding this miraculous plant is her earnest mission.
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