what does f1 strain mean

Basic Genetics Terminology For Cannabis

Our beloved marijuana strains are produced using several different breeding methods. Check out the terminology used to describe the unique genetics of different cannabis varieties.


Breeding cannabis is a complicated art that can be performed in plenty of ways. Here, we describe the common terms surrounding various cannabis genetics and how they came to be. We decided to keep it short and concise, as all the scientific minutiae can be very complex.


Landrace varieties originate from regions where cannabis plants have been growing for a very long time in the wild—centuries, or even millennia. This naturally creates stable, robust genetics that produce a homogeneous offspring. This means that the landrace strains from a particular area will develop very similar growth patterns, appearance, and chemical composition. Hindu Kush or China Yunnan are examples of pure landrace strains.

F1 stands for a “first generation hybrid”. When two strains with completely different genotypes breed, for example, a Master Kush with Durban Poison, their offspring will be an F1 hybrid. When this hybrid is bred together with another F1 hybrid from the same batch (a sister or a brother), it creates an F2 hybrid. When this process is repeated, it creates an F3, then F4, and so on. After F5, the plants can be considered as IBL.

IBL stands for “inbred line”, meaning that after several generations of hybridising a specific lineage, the strains become almost like a different family of strains. Skunks were hybridised and selected for their very pungent and potent nature, and after many generations, they developed into the Cheese family, which can be called an IBL.


Poly-hybrids derive from mixing completely different hybrids with each other. For example, Master Kush and Durban Poison produce offspring called F1(A); AK-47 and White Widow produce an offspring called F1(B). When F1(A) and F1(B) have a lovechild, it will be coined as a poly-hybrid.


Backcrossing refers to taking a hybrid strain and breeding it back with the original parent. For example, a male Chocolope and a female Jack Herer develop an F1 hybrid. When this F1 hybrid is hybridised with the original female Jack Herer, the resulting strain will be coined as BX1. When this BX1 gets backcrossed again with the original female Jack Herer, it will be coined as BX2, and so on. The genetics of the original female strain can be retained by keeping the plant in the vegetative stage as a mother, keeping the cuttings as clones or using tissue culture propagation.


Selfing is when a mother plant is pollinated by herself. Breeders use special chemicals on female plants to induce stress, which results in the plants producing male flowers, which produce pollen. When this pollen in used on the female flowers of the same plant or a clone from the same mother, the resulting seeds will be “selfed” or coined as S1. When the S1 seeds are backcrossed with the original parent, they’re called S2, S3, and so on. Breeders often do this to preserve the genetics of the strain, and to feminize the seeds.

Cannabis genetics are not all the same. We are here to clear up any confusion surrounding breeding terminology, from landraces to IBL.

What does f1 strain mean

Frequently Asked Questions:

Genetics 101 & Terms

В F1,F2,F5’s and IBL’s what is the difference and what’s that mean?

A- Put simply, a F1 is the result of the final parent crossings 1st seed set. The F2 would be the seeds from the F1 crossed together , and so on. A F1 will have both parents represented in the seed stock. A F5 will have little variance, very uniform, and very similar to the parent line. A IBL stands for In Breed Line . This is when over 90% of all seeds share the same traits, and growth patterns. So in short F1’s will give you some variety in phenos, and a F5 will give you very similar plants. Beyond F5’s and F6’s you start to find that sometimes genetic redundancies, and loss of vigor happen. We try to only create up to F1’s to F3’s for this reason, and to insure that you have a stable seed backup.

В Pheno, whats that?

A- A Pheno simply, is a set of traits that define a group of plants, from 2 different parents of the same seed set. Example: Lets say we crossed, Haze x Afghani #1. The haze is 100% Sativa, the Afghani #1 is 100% indica, and together they make a 50/50 mix of both. 1 pheno in those seeds would be plants that exhibit mostly sativa, “Haze” traits. That would be the “Haze or sativa” pheno. The same would be for, both the “Mostly Indica or Afghani #1” pheno, and the 50/50 mix of both, being the Seed Strains pheno itself.

В Why are all of your “Breeder Basics” packs F1’s?

A- F1’s are the best way to be able to pick a individual genetic pheno. F3 and above packs will exhibit a similarity that we were ideally breeding for. Seeds of a F1 cross, of lets say Kush #1 (Hindu Kush x Afghani #1) ideally in theory, would exhibit В to have 25% mostly Hindu Kush phenos, 50% evan mix (Kush #1) phenos, and 25% Mostly Afghani#1 phenos. This gives you 3 Phenos to individual and pick from to suit your needs, for your breeding project. Over 80% of all seed stock sold by most company’s is mainly F1 stock.

В Do all Cannabis Strains breed really well together?

A- No, not all Cannabis go together well. Pure Sativas and Pure Indicas might have to be crossed more times, to create a stable stock. More work has to go into a project like that. Crossing 2 Pure Indicas together has much more probability of having a better combination outcome, with less crosses to stabilize, if any. The same also generally applies to 2 Pure Sativas crossed together. Every strain is different in it compatibility, and it Dominate and recessive traits.

В Dominate and Recessive traits whats that mean?

A- Dominate traits have a greater likelihood of passing the trait to the next generation. Recessive traits that are present in the parent plant, wont be as likely to be passed, or have a low percentage of the recessive traits in the next generation. Plants are usually designed with mostly these traits in mind, to make it harder for copycat breeders to come out with a stable F2 stock of their own.

 So do you breed for Recessive genes or dominate and what’s that mean for me?

A- We breed for seeds to have the most stable and true outcome. We incorporate as many dominate genes as we can, to insure your breeding project will carry with it ,the traits you wanted to pass down to the next cross. We know that this will mean our strains might have more “knock offs” than the next guy, but like TreeTown says “You can can copy, but you can’t replace the original”. For this reason we don’t release any strain crossed by itself from another bank other than landraces, and banks that are not releasing stock anymore.

В Are there any instructions on how to grow your strains?

A- All grow reports, fertilizer strategy, and tips are located on the bottom of each description of the strain on our strain page, as soon as the strain is released.

What does f1 strain mean Frequently Asked Questions: Genetics 101 & Terms В F1,F2,F5’s and IBL’s what is the difference and what’s that mean? A- Put simply, a F1 is the result of the