F1, F2, F3, F4, F5 and IBL Cannabis Seeds

Cannabis is a fascinating plant with an interesting history. It has been used for medicinal and recreational purposes for centuries, and the demand for it is only increasing. There are many different strains of cannabis, each with its own unique properties. In this blog post, we will discuss F1, F2, F3, F4, F5 and IBL cannabis seeds in detail. We will explain what they are and how they are grown. We will also highlight some of the most popular strains of cannabis seeds available today. So if you’re interested in learning more about these strains, keep reading!

What Are These Combination Between Short and Long Photoperiod Plant Strains? 

There has been a rise in demand for unique cannabis strains. Breeders are tasked with creating new strains that have pleasant characteristics such as giving the user a good high or containing delicious aromas of candy and fruits etc. These positive traits are selected to be bred again to emphasize them more. However being a breeder is not an easy job as it requires precision and practice because not all experimented combination between short and long photoperiod plant crosses will turn out well and be loved by cannabis enthusiasts. 

F-series cannabis strains are bred from two parents that are known for their desirable traits. The first number in the F-series designation (F0) refers to the generation of the seed. The second number (Fx) is simply a way to identify each strain within the F-series. IBL cannabis seeds are also known as “true breeding” strains. This means that the seeds will produce plants that are genetically identical to the parent plant. IBL strains are always a good choice for growers who want to ensure consistent results.

The F derives from Filius, the Latin word for “son” which means that these strains are birthed from two parent strains. F1, F2, F3, F4, F5 and IBL cannabis seeds are all popular strains of cannabis that are grown by many people. They each have their own unique properties and benefits.

F1 Strain

F1 is known as a first generation because it is the result of a cross between two purebred cannabis plants. This is aiming to draw out the dominant characteristics like big buds, tallness, rooting, growth potential, color, and yield, amongst many others. F1 plants not only provide quality yield but stability in phenotypes, as well as those grown in the future. If the combination between short and long photoperiod plant cross is successful, then the breeder can focus on perfecting the strain for its good traits. 


F2 is bred from two parents where at least one parent is an F1 strain, however both parents can be F1. This strain is unstable because the plant grown can have a variety of phenotypes from the previous genetic background of the parents as the possibilities are many. In pursuit of a stable strain, then the breeding process needs to advance to F3! 


This is made from two F2 parents. If this is accomplished then stronger stability is present. It is important to note that the outcomes and progression from F3 is solely dependent on the breeder and what they want to create. For example, if the breeder wanted  a moderately short plant then they will breed in more recessive genes for the lack of height into future generations. Although you have to observe the combination between short and long photoperiod plant carefully and note its stability levels and its phenotypes. This stage tends to be the most impactful because of how unstable F2 is, so to get it to become stable, it needs a lot of patience! 


F4 seeds are the results of breeding F3 seeds. Again, for more stable seeds with pleasant traits, breeding will carry on in the fifth generation. 

F4 has a smaller range of phenotypes present in the outcomes of the plant. By carrying on with the selection process, the plant is going to become more stable as there is a higher chance of producing identical combination between short and long photoperiod plants. Genes like the scent produced or the amount of yield a plant produces will become identical to other F4 plants grown. 


By this stage, the act of perfecting the breeding is exercised and the strains have predominantly dominant and pleasant traits. With all the pleasant traits passed down from four generations, a new species is created with stronger levels of stability. 


IBLs are the final stage after F5. IBL stands for “inbred line”. This strain creates a balanced and homogenous offspring with pleasant and specific characteristics for future generations that will be grown. Essentially, this strain has reached stability. 

What are the differences between F1, F2, F3, F4, F5 and IBL cannabis seeds?

F1, F2, F3, and F4 cannabis seeds signify successive generations of breeding, with each displaying variations in uniformity and vigor. F1 represents the first crossbreed offspring, famously reliable for uniform traits—a fusion of dominant genes from purebred parents. F5 continues the line through further breeding. IBL, or Inbred Line, cannabis seeds come from extensive self-crossing to achieve a stable strain. Understanding what is F1 hybrid is crucial for growers seeking consistent quality and traits in their first-generation plants.

Contact Green Nexus For Your Seeds

Cannabis strains may seem complicated because of the variety that is available. If you are seeking information on cannabis seeds, check out our detailed strain profiles or get in touch with our team at [phone] for clarity. We’ll be sure to help you make the best choice for your unique circumstances.