Cannabis seed breeders often refer to F1, F2, S1, IBL & BX marijuana seeds. Find out what the terms mean and how they evolved. Learn how cannabis breeders combine strains to enhance, strengthen, or combine traits & effects of cannabis to create the perfect experience. Use this technique to create your own cannabis strains and breed weed seeds to preserve genetics – or cross-breed some more!
What are F1, F2, S1 cannabis seeds?
To many people cannabis seeds are simply cannabis seeds. But breeders and connoisseur growers also use different terms for cannabis seeds, such as F1, F2, S1 etc. In this review, we will explain what is meant by these terms and precisely what they tell you about the cannabis seeds which they describe.
|●||The basics of cannabis genetics for breeders|
|●||Different types of F1 cannabis seeds|
|●||The difference between F1 and F2 cannabis seeds|
|●||How does selfing produce S1 cannabis seeds?|
|●||Cannabis genetics hybridisation process case studies|
|●||Cannabis seeds quality: what to know before growing?|
The basics of cannabis genetics for breeders
Most home growers tend not to worry too much about terms such as F1 cannabis seeds, F1 hybrid cannabis seeds etc. So long as the seeds contain reliably good quality genetics few people are too concerned about the terminology used. However, to many cannabis breeders it is vitally important to understand the sometimes subtle, but critical, differences.
What does f1 hybrid mean? Cannabis seeds are formed when pollen from the male pollinates a female plant. The male genetics cross with those from the female to create F1 cannabis seeds, meaning that the cross is a First generation cross. If the parents were from two different strains the result would be F1 hybrid cannabis seeds.
Note that male pollen spreads easily and will pollinate any nearby female plants. That’s why professional breeders have isolated, dedicated breeding rooms which prevent accidental pollen spread. Pollen may be applied with small brushes using e.g. paint brushes, allowing specific branches to be pollinated with pollen from different males if required. Or male and female plants may share the same room, pollen is spread simply using air circulation fans.
Anyone involved with breeding/pollen would normally shower and change clothes to prevent unintended cross contamination between different areas of their breeding facility. Once pollinated, the female plant focusses much of her energy into seed production (rather than bud production).
What are F1 hybrid cannabis seeds?
F1 cannabis seeds simply mean that they are a first generation of offspring from the parent strains. Hybrid vigour is a term often used when discussing cannabis seeds, along with the question ‘Can an F1 outbreed for hybrid vigor?’ Cannabis hybrid vigour is observed when different strains are hybridised in an F1 cross.
If the parent strains were quite different indica and sativa strains then the seeds would be called F1 hybrid cannabis seeds, these may show vigorous growth and display ‘hybrid vigour’ resulting in growth which is faster than usual. This extra growth vitality is seen when different cannabis genetics are hybridised to create an F1 cannabis cross.
Different types of F1 cannabis seeds
F1 cannabis seeds explained! You can buy F1 autoflowering cannabis seeds or photoperiod F1 feminised cannabis seeds. Autoflower seeds tend to have a reputation for being faster and perhaps a little easier/more convenient than feminised seeds, but much depends on the preferences of the grower. F1 regular cannabis seeds are also popular with some old school growers or those conducting their own breeding experiments.
F1 fast cannabis strains are also available, with strains such as Think Fast. These strains have recessive autoflower genetics which cause the f1 fast cannabis strains to grow from seed to harvest a couple of weeks faster than traditional strains. For some outdoor growers this could be the difference between a harvest which ripens before the bad weather arrives and one which doesn’t.
Many connoisseur growers prefer to buy genuine F1 cannabis seeds in order to get the highest chance of the consistent quality results which are most similar to the parent strains. F1 White Widow cannabis seeds from Dutch Passion are a good example. The large numbers of repeat White Widow growers know that their best chances of producing original Grade-A White Widow buds is to use F1 White Widow cannabis seeds.
The difference between F1 and F2 cannabis seeds
F1 cannabis seeds are produced when two parents are crossed. When you see F1 cannabis seeds for sale you would normally expect them to show the closest qualities to the original strains. When the F1 cannabis seeds are grown and subsequently crossed the resulting seeds are known as F2 cannabis seeds.
The subject of F1 and F2 cannabis genetics can be a complicated subject, with questions such as ‘is F1 better than F2 cannabis?’ Whether you get better results with F1 vs F2 cannabis seeds will depend on the individual phenotypes being grown, as well your definition of the word ‘better’. It is perhaps safest to say that F1 cannabis seeds are more likely to show results closer to the original parents compared to F2 seeds.
Note. Growing and crossing F2 cannabis seeds would produce F3 cannabis seeds.
What are inbred line cannabis seeds (IBL)?
Inbred line cannabis seeds, often known simply as IBL seeds, are the result of inbreeding the descendants of the F1 cannabis seeds. It is usual to breed for 5 or more generations (F5) in order to be regarded as inbred line cannabis seeds. At this point the IBL may often be considered as a distinct strain in its own right.
Remember that the cannabis seeds have been produced from plants with genetics which are practically identical over several generations. Although this type of breeding is arduous and may take several years, the resulting cannabis seeds are typically very consistent with highly predictable results for the grower.
The Skunk family of cannabis seeds is an example of in-breeding which has allowed the successful preservation of the distinctive skunk aroma and taste.
What are poly-hybrid cannabis seeds?
The most reputable cannabis seed suppliers work hard to identify the best genetics and then stabilise them, a process which sometimes takes several years. Stable consistent cannabis seeds give the grower the best chance of replicating premium quality genetics in their own grow room. However, if two (F1) hybrid strains are crossed the result is poly hybrid cannabis seeds.
When growing such seeds you can reasonably expect any of the genetics from the diverse parentage to be expressed. For some growers, variety is a good thing. For other growers seeking a tent full of consistent/uniform plants, poly-hybrid cannabis seeds are unwelcome guests.
Many of the less experienced seed suppliers intent on making a ‘fast buck’ simply cross male and female plants to create rapid seed production with absolutely no thought given to stabilisation or optimisation of the genetics. Be sure to do your research carefully before buying cannabis seeds and choose seed banks with a good track record of customer service, plenty of repeat customers and perhaps a few cannabis cups. Cannabis cups are usually a sure sign that your seed bank takes their profession seriously and is there for the long haul.
|Dutch Passion cannabis cup winning strains|
How does selfing produce S1 cannabis seeds?
What does F1 and S1 mean? Female cannabis plants can produce S1 cannabis seeds through a process known as ‘selfing’. Usually this involves taking a cutting/clone from the female mother plant and turning it into a male by a process known as ‘reversion’.
This can be done by spraying the female with a chemical such as Silver Thiosulphate. The stress of this causes the female to become a male plant. Pollen is then collected from this plant and used to pollinate the original mother plant. This allows the original female to effectively be ‘self-pollinated’ or ‘selfed’. The cannabis seeds are known as S1 seeds and have the added stability benefit of using the ‘same’ genetics from the male and female.
Cannabis genetics backcrossing explained
When two parent strains are crossed the result is an F1 cannabis seed. If this seed is grown and crossed with one of the original parents, it is known as backcrossing. Backcrossing is a way of stabilising a cannabis strain since it allows parent genetics to be backcrossed with genetically similar offspring. As a result, greater genetic stability is conferred on the resulting cannabis seeds. This produces more consistent seeds with more predictably uniform results in your grow room.
Cannabis genetics hybridisation process case studies
Often cannabis breeders will aim to combine two great qualities from different strains into a new hybrid. Often this will involve e.g. taking the cannabinoid content from one strains and augmenting it with XXL yields from another.
Orange Hill Special
Orange Hill Special is a Dutch Passion photoperiod feminised seed variety. She was in-bred over 6 generations after the initial crossing with genetics from Orange Bud and Californian Orange.
Orange Bud and Californian Orange are both members of the multi-cannabis cup winning Orange Family of cannabis seeds. These strains stand for premium quality harvests of beautifully citrus scented buds. Orange Bud and Californian Orange have slightly different but complementary terpene profiles. The aim of the hybridisation was to combine the best features of each variety into a new stable strain which would embody the best taste, THC levels and yields.
Orange Hill Special is a member of the most potent cannabis seed selection available, the High THC cannabis seed collection. This is where you can expect consistent 20-25% THC levels across all plants when grown in good conditions. Such stability and consistency don’t arrive by accident, it’s the result of several years of careful selection, lab analysis, stabilisation and careful breeding. If you’re looking to grow heavy harvests of extremely THC rich citrus scented skunk buds then Orange Hill Special is a perfect choice. For best results, LED grow lights are recommended.
Cannabis Breeding: How Are New Strains Created?
While browsing Leafly’s strain database, you may wonder what a cross of this and that strain is, what a hybrid or a backcross is, or what a parent strain is. All of these have to do with plant breeding—essentially, breeding a male and female plant to combine or refine the genetics of two plants or strains. Breeding two different strains often results in a new strain, or hybrid.
Cannabis breeders typically breed to purify and strengthen strains, combine strain traits, or enhance specific characteristics.
Cannabis breeders typically breed to purify and strengthen strains, combine strain traits, or enhance specific characteristics like higher yields, specific aromas, potency, and many other things.
When growing and breeding, it’s important to know where your seeds come from and what kind of genetics they have. If the seed breeder can’t give you a detailed history of how a packet of seeds was bred or what they were crossed with, you never really know what you’re getting.
Plant breeding is a fundamental process of growing cannabis. Breeding is highly technical and typically done on a commercial scale, but with legalization increasing, breeding is becoming more popular. You can even do it yourself.
The Basics of Breeding
Cannabis plants can be either male or female. Cannabis consumers are mainly concerned with female plants, because only females produce the sticky buds that we all know and love. But male cannabis plants are important for the breeding process, as they are needed to pollinate the bud-producing females.
Take the strain Super Lemon Haze as an example. It’s a hybrid (or a “cross”) of Super Silver Haze and Lemon Skunk—these are the parent strains. At some point, the breeder decided that they liked some attributes of Super Silver Haze and some of Lemon Skunk and decided to combine the two.
To do this, you need a male of one strain to pollinate a female of the other. Once pollinated, the female will then produce seeds that express the genes of both the male and female plant. Those seeds will be harvested and grown separately, and voilà: You have created a hybrid.
So how do you know whether to pick a male or a female of each strain that you’re crossing?
“Often in cannabis, the traits of the female carry over to progeny (seeds) more than the male. That said, the traits of the male are often obvious to the discerning grower so one should definitely choose a male that will complement the traits of the female,” says Nat Pennington, founder and CEO of Humboldt Seed Company who’s been breeding cannabis for 20 years. “So much is possible with truly intentional breeding strategies.”
How to Breed Cannabis Plants
After two parent strains are selected for breeding, a male and several females are put into a breeding chamber to contain the pollen. A breeding chamber can be as simple as an enclosed environment with plastic sheeting on the sides, or a specially designed sterile environment for large-scale breeding.
“A healthy male can pollinate up to 20 females, and by pollinate, I mean absolutely cover the plant with seeds.”
A single male plant can pollinate tens of females. “It’s always a good idea to have only one male, genetically speaking, per pollination effort,” says Pennington. “A healthy male can pollinate up to 20 females, and by pollinate, I mean absolutely cover the plant with seeds.”
This is intentional breeding—any grower who’s accidentally grown a male and pollinated a crop will know that one male can easy pollinate hundreds of females, filling your whole crop with seeds.
Once in the breeding chamber, you can grow the plants vegetatively for a few weeks to let them get bigger, but it’s not necessary. Put them on a flowering light cycle: 12 hours of light, 12 hours of dark.
The mature male will grow pollen sacs within the first couple weeks of its flowering phase. Pollen will release from the sacs, move through the air, and land on the female plants, pollinating them. Having an enclosed breeding chamber is important to contain the pollen and also to prevent outside pollen from getting in.
You can also help along the pollination effort by shaking pollen from the male onto the females, or by collecting pollen from the male and directly applying it to the females. These female plants will continue to grow and flower, during which they’ll grow seeds (as well as buds). These seeds will express the genetics of both the male and female plant.
When the seeds are mature, they are harvested and stratified (or dried). “The secondary process of maturation happens after the plant is dead, and the seed needs to be stratified before it will germinate,” says Pennington. “In general, harvest for flower takes place three to four weeks before harvest for seed.”
These seeds—now a hybrid of the two parent strains—will be grown on their own, outside of the breeding environment.
But the process doesn’t end there. The hybrid strain that you buy at the dispensary has likely gone through many rounds—or generations—of breeding to strengthen its genes and to ensure that its descendants are healthy and consistent.
Just as you and your sibling might have different physical attributes from your parents, each seed created from a round of cross-pollination will have different attributes from its parent strains. Maybe you have your father’s eyes and your mother’s hair, but your sister has your mother’s eyes and hair. Each cannabis seed is unique and will express different traits, and different combinations of traits, from one or both of the parent strains. These seeds with various expressions are called phenotypes.
Homozygosity ensures that a plant will consistently produce the same seeds with the same genetic makeup over and over again.
A plant that produces a set of phenotypes that have a lot of variety are said to be heterozygous. With cannabis, you typically want seeds that are homozygous—ones that have the same set of genes. Homozygosity ensures that a plant will consistently produce the same seeds with the same genetic makeup over and over again, ensuring that buyers and consumers will get the same plant or seed time and again.
After a strain is crossed, a breeder will then have to select which phenotype of the new strain they like best. For large-scale growers, they want to choose the best phenotype for mass production.
Back to the Super Lemon Haze example: This strain takes a lot of its bud structure, trichome and resin production, and overall appearance from Super Silver Haze. But it takes its flavors and aromas from Lemon Skunk.
Lemon Skunk also tends to grow extremely tall and has loose buds, whereas Super Silver Haze grows smaller and has denser buds. Through selecting specific phenotypes, a breeder can pick one that has the attributes they want to keep. In this case, a phenotype that has the structure and bud density of Super Silver Haze and the flavors and aromas of Lemon Skunk.
Most likely, there were early phenotypes of Super Lemon Haze that grew tall and loose like Lemon Skunk, or tasted more like Super Silver Haze. But the breeder discarded those phenotypes and keep growing the ones that have the attributes of what we now know is Super Lemon Haze.
High-quality breeding still doesn’t stop there. Once a breeder has crossed a strain and narrowed down a phenotype and finally has the one, they will usually backcross that strain to strengthen its genetics.
Backcrossing is a practice where a breeder will cross-pollinate the new strain with itself or a parent—essentially, inbreeding the strain. This makes the strain more homozygous, and strengthens its genetics and desirable characteristics, and also ensures that those genes continue to pass down from generation to generation.
The hybrid that you bought from the dispensary has gone through months and even years of growing, crossing, and backcrossing, as well as a selection process to pick the best phenotype of that strain.
Breeding is about time and patience. Says Pennington: “To be a breeder, you have to be willing to accept the fact that you won’t have uniformity in the offspring, [you’ll get] lots of ugly ducklings in the hunt for your golden goose. To make seeds that will actually reflect the golden goose takes time, and it takes more than just a one-off cross. Even after you found your golden goose, expect to have to do a whole number of stabilizing backcrosses to reproduce your golden goose in seed form.”
How To Easily Breed Seeds And Create New Cannabis Strains
Maybe it’s not every growers ambition to start their own seed company – and nobody’s saying you should. Though it can be pretty cool to create your own cannabis strain. Just imagine you’d be the one creating the next Tangerine G13 or Amnesia Haze – or another legendary, award-winning weed variety.
Imagine you’d be the one creating the next Tangerine G13!
Creating own cannabis varieties is pretty easy too and could potentially be a green goldmine. Even if you don’t create the next Super Silver Haze on your first try, it is still worth trying. Cross-breeding your own weed strains is very educative and results in a huge collection of cannabis genetics. Meaning you might hold seeds to strains that are no longer being produced – to cultivate or cross-breed with.
Crossing Weed Strains
There is one thing you definitely need if you’re planning to breed your own weed strains: male cannabis plants. Unless your plan is to make feminized cannabis seeds, which is a different story we’ll dive into another time. To recognize and distinct male from female (and hermaphrodite) weed plants, have a look here.
Because although you can grow male cannabis plants in the same room as female cannabis plants. It’s important to separate the males before their flowers open, releasing their pollen into the room, to avoid uncontrolled fertilization.
Rest assured, there is no need for a separate grow room for the male plants to develop from there. As a flowering male can be held under a simple lightbulb or simply in the windowsill. Furthermore, you can even cut off a few branches and put them in a vase to collect the pollen a week later. Regular Cannabis seeds create male and/or female plants.
Selecting Parents For Your Strain
The trick to select the perfect male weed plant is to have good and above all trained senses. Because it’s up to you to see which male has the best growth and the most attractive (or present) aroma.
Hollow stems on male cannabis plants may indicate high THC-production in its offspring
Obviously, only select male cannabis plants with a nice structure and a healthy root system. If possible, cut off a few branches in search of hollow stems. As a hollow stem in weed plants is often an indicator for high THC-production in the plants.
Male plants that are quick to flower are often dominant in passing on their genes – so it’s best to leave those be. Late-bloomers however, carry recessive genes.
Crossing your female plant with late-blooming males will therefore retain the desired characteristics from your fem – instead of your cross turning into a copy of your male parent. If you’re serious about selecting the right male, make sure you have a separate room for them. As there you can leave them to flower longer, to discover more about their grow characteristics.
How To Collect Cannabis Pollen
Now you’ve selected the right male, it’s time to collect its pollen. A pretty easy job considering the plant is eager to release its pollen to fertilize female plants. Simply shake a branch with open male flowers above a sheet of (black) paper or a plastic container. And the pollen will fall down from the flower onto the desired surface.
Make sure there are no vents on and windows are closed though. As the male cannabis pollen is designed to travel with wind – and in this case we’re trying to contain it to not fertilize the wrong (or too many) female plants. Also avoid working with your female plants right after this job, as pollen easily sticks to your clothing and hair.
Fertilizing Female Weed Plants
Selecting the ideal female cannabis plant is easier than selecting males. As you can truly judge the fruits before you put in the labor. To guarantee a stable plant, try growing her out of seeds and cultivate it from clone too. Thereafter, you can choose the characteristics you like to see in your own creation(s). Be sure to take aroma, structure, flowering time, esthetics, taste and effect into account – as those are the most important elements to look for in a good cannabis plant. Logically, only select the best of the best females to create your own weed seeds with.
Simply use a paint brush to pollinate your female cannabis plant, with the collected male pollen. [Image: Gracie Malley / Cannabis Now]
Pollinating your female cannabis plants is as easy as collecting male pollen. Preferably wait until the plant(s) you want to fertilize are three to five weeks into their flowering period. Then take the selected female out of the grow room, again, to avoid uncontrolled pollination of the rest of the plants. Label one or more branches to fertilize, to know which plant was crossed with which and when. And use a clean (paint) brush to apply the pollen on one or more branches for seed production – leaving the rest of the flowers to produce seedless weed: sinsemilla.
Deactivating Cannabis Pollen
About three hours after fertilization, it is time to deactivate the leftover pollen on the plant. You can do that by simply spraying your plant with water. Be sure to change your clothes and have a shower after this, before you place the fertilized female back in the room.
After fertilization, you can let your cannabis plants fulfill their flowering period until they are ready to harvest. The seeds are fully grown after two to six weeks, but can stay in the bud and hung to dry after harvest. Your home grown cannabis seeds then require another month before they’re ready to be germinated – preferably with our favorite germination method.
Be sure to keep an eye on them once they start flowering, as you’ve now produced ‘regular cannabis seeds’. This means your plants can turn both male or female when they enter the flowering stage. Providing you with what you need to further stabilize your creation into the perfect weed strain.
What strain would you choose to cross your own variety with?
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The germination of cannabis seeds is illegal in most countries. Amsterdam Genetics cannabis seeds are exclusively sold as collectable souvenirs to customers living in countries where the cultivation of cannabis is illegal. All information on this website is intended for educational purposes only and is not meant to incentivize people to engage in illegal activities.