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F1 Fast Version® seeds

F1 Fast Version® strains are 100% photoperiod-dependent versions featuring ultra-fast flowering of some of the most appreciated genetics from the Sweet Seeds® genetic collection. These new genetics are F1 hybrids. When grown indoors, these marijuana plants are ready to harvest just 6 or 7 weeks after the photoperiod switch to 12 hours of light and 12 hours of darkness. When grown outdoors, the plants anticipate harvest for about 1 to 2 weeks regarding to their original versions.

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F1 Fast Version® seeds

Strawberry Cola Sherbet F1 Fast Version®

F1 Fast Version® seeds

Sweet Mandarine Zkittlez F1 Fast Version®

F1 Fast Version® seeds

Green Poison F1 Fast Version®

F1 Fast Version® seeds

Tropicanna Poison F1 Fast Version®

€19.60 €28.00
F1 Fast Version® seeds

Gorilla Girl F1 Fast Version®

F1 Fast Version® seeds

Crystal Candy F1 Fast Version®

F1 Fast Version® seeds

S.A.D. Sweet Afgani Delicious F1 Fast Version®

F1 Fast Version® seeds

Sweet Cheese F1 Fast Version®

F1 Fast Version® seeds

Big Devil F1 Fast Version®

F1 Fast Version® seeds

Jack 47 F1 Fast Version®

F1 Fast Version® seeds

Cream Caramel F1 Fast Version®

F1 Fast Version® seeds

Killer Kush F1 Fast Version®

F1 Fast Version® seeds

Sweet Skunk F1 Fast Version®

F1 Fast Version® seeds

Gorilla Sherbet F1 Fast Version®

F1 Fast Version® seeds

Cream Mandarine F1 Fast Version®

F1 Fast Version® seeds

Red Mandarine F1 Fast Version®

F1 Fast Version® seeds

Black Jack F1 Fast Version®


Due to their fast flowering, these strains are very appropriate for growing in humid and rainy zones, in high mountains or regions with cold winters. In these areas that are especially sensitive to fungus attacks, these strains are very adequate because they manage to anticipate harvest to the season when the most virulent botrytis (grey mold) attacks, decimating the buds of the plants that feature longer flowering periods.

What are F1 Fast Version® strains?

Photoperiod-dependent strains are genetics that flower according to the photoperiod (the hours of light and darkness that plants are subjected to).

F1 Hybrids are the first resulting generation of the hybridization between two different and stable varieties. They combine the valued “stability” and also the appreciated “hybrid vigor” in the same generation. The more stable (homozygotes) the parentals and the larger the genetic distance between both of them, the greater this “hybrid vigor” and “stability” is.

The F1 Fast Version® strains are the first filial generation (F1) resulting from the cross between a photoperiod-dependent genetic and an autoflowering genetic. The result of this hybridization between two stable and totally different plants (at least regarding the type of flowering) is known in genetic terminology as “F1 Hybrid”. The F1 Fast Version® strains are hybrid genetics, 100% photoperiod dependent and featuring a very fast flowering stage.

The photoperiod-dependent parental contributes with its photoperiod-dependent trait to the F1 Hybrid in all the offspring. This happens because the photoperiod-dependent characteristic is dominant regarding to the autoflowering characteristic that, on the other hand, is recessive.

The autoflowering parental contributes with a very fast flowering and maturation of the flowers to the Hybrid F1 in all its offspring. In this case the heredity is in a half-way point and the autoflowering genetic reduces the duration of the flowering stage of the photoperiod-dependent parental in between 1 and 2 weeks.

At Sweet Seeds® we have used this type of hybridization that leads for a reduction in the flowering time in some of the most appreciated genetics from our catalog, creating versions with a very-fast flowering of some of our most appreciated photoperiod-dependent genetics.

Sweet Seeds® was the first feminized marihuana seed bank that released this type of hybrid genetics in the market. They are available in the cannabic scene from 2013.

What makes F1 Fast Version® strains so fast in flowering?

The fast flowering of our F1 Fast Version® genetics is mainly due to the type of autoflowering genetics that intervene in the cross. At Sweet Seeds® we select the fastest-flowering autoflowering genetics for the production of these photoperiod-dependent strains featuring fast flowering.

There are a lot of types of autoflowering genetics regarding the duration of their life cycle. Some autoflowering genetics may even need 4 months to complete their life cycle, with a flowering stage that may be of up to 2 months. At Sweet Seeds® we have always avoided to work with autoflowering genetics that feature long life cycles. The autoflowering genetics from our catalog feature a very short life cycle (from the appearance of the cotyledons till harvest), of between 7 and 9 weeks, with a flowering stage of between 4 and a half and 6 weeks. Obtaining very productive autoflowering strains that are resinous, aromatic and, at the same time, fast, is the result of long massal selection programs in successive generations.

The autoflowering specimens with the shorter flowering stage are selected for the production of F1 Fast Version® strains. These select autoflowering genetics featuring very fast flowering provide to the F1 Hybrid a very fast flowering in all the offspring when compared to the photoperiod-dependent parental.

Advantages of F1 Fast Version® genetics

Growing these strains allows for keeping all the advantages of the photoperiod-dependent varieties, such as:

  • Preservation of Mother Plants:

One of the main advantages of growing with photoperiod-dependent seeds is the possibility of preserving, for an indefinite time, clones of any special plant that we find. This can be done by keeping the clones with artificial lights in a photoperiod of 18 hours of light and 6 hours of darkness. With this light cycle the Mother Plants keep in the vegetative stage without ever getting into the flowering stage and they can be used to produce clones.

  • Vegetative Propagation:

These photoperiod-dependent plants can be multiplied in our garden by taking clones from our plant from seed or from our mother plant.

  • Height, size and production:

Keeping photoperiod-dependent plants with a vegetative photoperiod, for as long as we wish, we can control the height and size of the plants to obtain big sized plants and high production of buds. In outdoor growing, this allows us to get enough stock for our annual consumption with just a few plants. In the same way, controlling the photoperiod in order to induce the flowering without any vegetative growth, we can obtain the opposite effect: small and discreet plants with a fast life cycle. To plan the desired height in advance, we will have to take in consideration that, depending on the strain, the plants may double or even quadruple the height presented in the beginning of the flowering stage or since we start the change in the photoperiod in indoor grows.

Besides the previously mentioned advantages that are shared by all the photoperiod-dependent strains, the fast flowering of the F1 Fast Version® genetics allows for extra advantages for the cannabis growers:

  • Savings in the time spent in the grow:

The duration of our grows is very important. With this type of genetics we will be able to enjoy our weed a few weeks earlier.

  • Savings in electric consumption:

A very important detail for indoor growing with artificial lights, taking in consideration the prices of electricity and the contamination that it takes to produce electricity.

  • Savings in work and effort:

If we harvest a few weeks before, we will consequently dedicate less time to taking care of our plants. We can dedicate this time to other hobbies and to enjoy our harvest.

  • Savings in flowering nutrients:

With a shorter flowering time we will also consequently use less flowering nutrients.

  • Allowing to anticipate harvest to fungus attacks and to the cold and rainy weather:

This is one of the most important advantages of F1 Fast Version® genetics. This advantage can be a particular benefit for outdoor growers from humid and rainy areas, high mountain zones or regions with harsh winters. Fast-flowering marihuana plants can anticipate harvest to the most virulent season of fungus attacks, that decimate the buds in long time flowering plants. It also allows for an anticipation to the arrival of bad weather and the cold. These genetics are ready to harvest between late August and early September in the Northern Hemisphere. Late February to early March in the South Hemisphere.

  • Strong presence of the Hybrid Vigor or Heterosis:

As they are F1 Hybrids, they feature strong hybrid vigor. The hybrid vigor phenomenon is normally expressed in a quantitative way. This means that they are measurable and in marihuana they are usually expressed as:

    • Increase in production.
    • Better adaptation to the environment.
    • Greater resistance to plagues and disease.
    • Greater tolerance to environmental stress.
    • Increase in the growth speed.
    • Greater precocity (reduction in the time needed to achieve maturity).
    • Increase in the general size of the buds, stems, leaves, etc.
    • Increase in the total number of nodes, leaves, flowers, trichomes, etc.
    • Increase of the amount of terpenes and cannabinoids.

    Not all the vegetable species feature the hybrid vigor phenomenon, although it is very frequent in the vegetable kingdom and it is expressed with greater intensity in allogamous species, which is the case of marihuana. The wider the distance between the parentals, the greater the hybrid vigor.

    • Great stability:

    As they are F1 Hybrids, these genetics show great stability. This is a very sought trait by all the growers. Even more when this stability is shown in characteristics that are desired and sought by the cannabis grower.

    Breeding and inheritance in F1 Fast Version® strains

    For the development of the F1 Fast Version® genetics we use the best selected autoflowering strains and the collection of elite clones from the Sweet Seeds® bank of mothers.

    The autoflowering or photoperiod trait is dependent on a single gene. This gene presents two possible alleles. One is dominant (F), which is the one that codifies the photoperiod character while the other one is recessive (a) and is the one that codifies the autoflowering character. As the allele that codifies the autoflowering character is recessive, to express this type of flowering it is required to be in a state of homozygosis, which means that all the autoflowering plants are (aa), as they have received a gene (a) from the father and another one from the mother.

    On the other hand, every photoperiod strains (elite clones) of the Sweet Seeds® bank of mothers that we use to produce F1 Fast Version® strains are homozygotic for the dominant character that expresses the photoperiod-dependent flowering. They are (FF) as they have received a (F) gene from the father and another one from the mother and this is something that we can deduce from the analysis of the offspring of these clones.

    The first resulting generation of the cross between these two types of strains –photoperiod (FF) and autoflowering (aa) –, obeying to the first Mendel Law or to the Hybrids Uniformity Law for the first filial generation, provides as a result a 100% of hybrid specimens (Fa) and as (a) is recessive and (F) is dominant, 100% of the population is photoperiod dependent and zero autoflowering plants show up. This first hybrid generation between homozygotes for one or multiple characters in the genetic line is known as F1 Hybrid.

    As it refers to a F1 seed, if we cross these seeds (Fa) with each other to obtain more seeds, then the second generation, known as F2, concurring with the second Mendel Law or Character Segregation Law for the second filial generation, will not produce 100% Fast Version (Fa) specimens anymore. Within the specimens originated from this procedure, we would obtain a mix of 25% autoflowering (aa), 25% photoperiod (FF) and 50% Fast Version (Fa). The only generation that is 100% Fast Version (Fa) is the F1 Fast Version®.

    Discovery of the F1 Fast Version® strains. The beginning

    At Sweet Seeds® we have been one of the feminized marihuana seed banks pioneer in the development of autoflowering genetics. And the first seed bank in the world to offer F1 Fast Version® genetics to cannabis growers.

    Around the year of 2007 at Sweet Seeds® we started our programs to introduce the autoflowering gene in our most appreciated elite clones, with the final goal of obtaining equally exquisite genetics but in autoflowering version.

    When we performed the first crosses between autoflowering genetic lines and our beloved photoperiod-dependent elite clones, we observed that 100% of the first generation was photoperiod-dependent. There was not one single autoflowering specimen. This was something expectable and indicated that the autoflowering character was recessive and the photoperiod-dependent character was dominant. But what really called to our attention in our first experiment was how fast the F1 Hybrid flowered. We even double checked our calendars to be sure that there were no mistakes in our annotations. We confirmed that there were no errors whatsoever. The cross with the autoflowering strain leaded to an important shortening in the flowering time to the F1 Hybrid and bud maturation happened about 2 weeks earlier.

    This new experiment was repeated each time that we wanted to develop a new autoflowering strain through hybridization between our best autoflowering genetic lines and elite clones from our bank of mothers. The successive experiments confirmed that the resulting F1 Hybrid from these crosses featured a much faster flowering than the photoperiod-dependent parental.

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