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High Grade Genetics
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22,50€ – 56,25€Price range: 22,50€ through 56,25€
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| Weight | N/A |
|---|---|
| Genetic Type | Hybrid, Pure Indica |
| Harvest Time | 10-12 Weeks, 8-10 Weeks |
| Harvest Yield | 400-500g/ m2, 500-600g / m2 |
| Seed Gender | Feminized Seed |
| Seedbank | Amsterdam Genetics |
| THC | High THC (20%), Mid THC (15%) |
| Where to Grow | |
| Country | Dutch |
| Effect | Muscular, Narcotic, Relaxing |
| Genetic Family | Blueberry, Skunk |
| Quality | Annibale's Choice, Most Productive |
| Taste and Smell | Berries / Grapes / Fruit, Cream / Butter / Milk, Pine / Wood / Balsamic, Spices / Incense / Cheese |
Double Blue Feminized by Amsterdam Genetics represents one of the most refined selections for those seeking the perfect fusion between violet aesthetics and the structural density of old-school indicas.
It is a cultivar that does not just offer an extraordinary visual impact, but guarantees a thick, oily resin production, optimized for variable climates and high-efficiency indoor setup.
Double Blue Feminized by Amsterdam Genetics is a clear indica-dominant hybrid born from the cross between the legendary Blueberry and the vigorous Silver Bubble. It features a stabilized flowering time between 8 and 10 weeks, with an indoor yield ranging between 400 and 600g/m². THC levels average between 15% and 20%, offering a very deep relaxing effect.
The plant develops a robust structure with a medium-short internodal space, facilitating the management of the vegetative plane. It is particularly appreciated for its ability to produce anthocyanins (purple/blue colorations) in response to slight nighttime temperature fluctuations.
Double Blue Feminized is the result of a breeding project aimed at stabilizing the aromatic traits of the “Blueberry” family without inheriting its typical structural fragility. The union with Silver Bubble brought the vegetative vigor necessary to support heavy flowers and swollen calyxes, typical of hash varieties.
A stabilized cross that maximizes tissue density and anthocyanin pigmentation typical of the Blue lineage.
Analyzing technical data on Seedfinder, it emerges how this plant maintains excellent resilience in high altitude and guerrilla contexts, inheriting a leaf robustness that protects it from environmental stresses. Double Blue Amsterdam Genetics is a plant that “communicates” heavily with the grower: the chromatic shift of the leaves toward cobalt and plum hues is not just an aesthetic trait, but an indicator of the correct biochemical maturation of the plant.
Growing Double Blue requires an expert hand in pH and mineral nutrition management. Varieties descended from Blueberry are historically sensitive to sudden changes in the leaf area and require a constant supply of microelements to avoid early chlorosis that could compromise the actual harvest weight.
Initial stretch is moderate, but the plant tends to fill out lateral volume very well. It is essential to manage the branch plane so that light penetrates to the base, preventing lower flowers from remaining underdeveloped.
In a protected environment, Double Blue Amsterdam Genetics responds magnificently to LED lighting with a spectrum enriched in blue and deep red. The use of the SOG technique allows for maximizing production per square meter, concentrating energy on the apical buds.
VPD monitoring is critical, especially between weeks five and eight: values of 1.2-1.4 kPa ensure the plant continues to transpire correctly, avoiding salt buildup in the root zone. A high intake of Magnesium and Calcium is mandatory to support thick resin synthesis and prevent necrotic spots on the wide leaves.
Outdoors, this genetic reveals its “mountain” nature. When grown at high altitude, the more intense UV radiation stimulates an even more massive trichome production as a defense mechanism. The root zone must be managed with pots of at least 35 liters to allow explosive growth during July.
Towards the end of September, the nighttime temperature excursion (ideally around 12-14°C) will activate anthocyanin production. This not only improves aesthetics but protects the flowers from late sun rays and fixes the terpene profile. Be careful with morning humidity, though: the buds are so hard and compact that natural ventilation must be guaranteed by an internal cleaning pruning (lollipop) performed with precision.
The aromatic profile of Double Blue is a triumph of berries and forest earth. Myrcene dominates the olfactory base, providing that musky scent that accompanies the physical relaxation sensation.
Linalool adds a floral lavender nuance, while Pinene refreshes the bouquet with balsamic pine notes. On the palate, the smoke is dense, almost creamy, with a persistent aftertaste of ripe blueberry and dark spices. During curing, the “Berry” note becomes more pungent, transforming into an aroma reminiscent of slightly toasted red fruit jam.
With a THC around 20%, Double Blue Feminized offers a primarily somatic experience. Users describe the effect as a “heavy blanket” wrapping the body, ideal for evening hours or moments of total pause.
It is a cultivar sought after by those who prefer varieties with a physical and narcotic profile, useful for melting away accumulated muscle tension. The perception is one of deep but serene sedation, which does not excessively weigh down the mind but invites rest. It is not a daytime variety: its nocturnal nature emerges strongly after the first twenty minutes.
The most common mistake with Double Blue is a pH swing in the substrate. A too sudden variation immediately blocks phosphorus and magnesium absorption, leading to a stop in the development of swollen calyxes and early yellowing of the leaf area.
Another risk is over-defoliation. This plant needs its wide leaves as a nutrient reserve for late flowering; removing too many stresses the genetics and slows down trichome production. Limit yourself to removing only the foliage that directly covers the lower flower sites.
Finally, poor ventilation in late flowering is fatal. With flowers this hard, botrytis can settle in the heart of the apical bud without showing external signs until the time of cutting. Keep extractors and fans at maximum speed during the last three weeks.
Original Blueberry is a masterpiece of flavor but can be very slow and fragile. Double Blue Feminized by Amsterdam Genetics is decidedly faster, more productive, and easier to grow, while keeping the aromatic berry DNA intact.
Blue Dream has a more marked sativa drive and airier flowers. Double Blue wins on bud physical density and the strength of bodily relaxation, making it more suitable for those seeking a pure indica experience.
Purple Punch bets everything on candy sweetness and aesthetics. Double Blue Amsterdam Genetics offers a more earthy, complex profile and superior agronomic resistance in less controlled outdoor environments.
This variety is not recommended for growers who cannot control ambient humidity below 50% during the final stages of flowering. Its bud density does not forgive air stagnation. It is also not recommended for those seeking an energizing effect for work or study: Double Blue will force you to slow down, making it difficult to concentrate on complex or dynamic tasks.
In full flowering, the plant responds well to an EC of 1.8. Avoid exceeding 2.0 if you do not see perfect transpiration, to avoid nutrient burns on the tips.
It usually lasts about 15-20 days from the photoperiod switch. The plant almost doubles its initial height.
They start showing around the sixth week, intensifying in the last two if the nighttime temperature drops below 16°C.
Yes, but monitor pH obsessively (5.8 – 6.0). Blueberry lines are less tolerant of acidity swings than Skunks.
Start flushing about 10-14 days before the scheduled harvest, when you see that most of the pistils have turned orange and the trichomes are cloudy.
A selection that convinces for its combination of structural vigor and sensory intensity. Double Blue Feminized develops flowers that are true purple resin jewels, adapting perfectly to those seeking high-level physical relaxation without giving up a generous commercial yield. An ideal cultivar for the grower who wants to combine “Blue” tradition with the security of a modern and resilient plant.
